# Sticky  Can we really hear a difference between amps?



## Sonnie

*Can we really hear a difference between two amps?*

More specifically... between two amps that have been level matched in a controlled listening test. We are not talking about amps that have been modified or are driven beyond their reasonable limits.

What a crazy and completely worn out question... I know, I know, but I figured why not have a bit of fun with it anyway. 

Naturally our ZERO TOLERANCE FORUM RULES are going to apply as they ALWAYS do! So... if you are one of those who simply cannot have a sensible discussion on a hot and debated topic... STAY FAR AWAY from this thread. 

Consider the following link and quoted articles:

*LINK*: *Science and Subjectivism in Audio*



> Any amplifier, regardless of topology, can be treated as a “black box” for the purpose of listening comparisons. If amplifiers A and B both have flat frequency response, low noise floor, reasonably low distortion, high input impedance, low output impedance, and are not clipped, they will be indistinguishable in sound at matched levels no matter what’s inside them. Of course, some of the new “alphabet soup” topologies do not necessarily satisfy those conditions.
> 
> I really believe that all this soul-searching, wondering, questioning, agonizing about amplifiers is basically unproductive and would be much more rewarding if applied to loudspeakers instead. For various reasons that I have discussed in the past, people are more willing to change amplifiers than loudspeakers. That’s most unfortunate because a new and better loudspeaker will change your audio life but a new amplifier will not.
> 
> —Peter Aczel, Editor & Publisher, The Audio Critic





> There has been a lot of hot chatter on the E-mail circuit over the past couple of months about the Steve Maki and Steve Zipser challenge in Miami. I thought you would appreciate a complete recount of the events. Zipser, a high-end salon owner, had issued a challenge that he would pay the airplane fare of any interested party who wanted to see him prove he could hear the differences between amplifiers.
> 
> On Sunday afternoon, August 25th, Maki and I arrived at Zipser's house, which is also Sunshine Stereo. Maki brought his own control unit, a Yamaha AX-700 100-watt integrated amplifier for the challenge. In a straight 10-trial hard-wired comparison, Zipser was only able to identify correctly 3 times out of 10 whether the Yamaha unit or his pair of Pass Laboratories Aleph 1.2 monoblock 200-watt amplifiers was powering his Duntech Marquis speakers. A Pass Labs preamplifier, Zip's personal wiring, and a full Audio Alchemy CD playback system completed the playback chain. No device except the Yamaha integrated amplifier was ever placed in the system. Maki inserted one or the other amplifier into the system and covered them with a thin black cloth to hide identities. Zipser used his own playback material and had as long as he wanted to decide which unit was driving the speakers.
> 
> I had matched the playback levels of the amplifiers to within 0.1 dB at 1 kHz, using the Yamaha balance and volume controls. Playback levels were adjusted with the system preamplifier by Zipser. I also determined that the two devices had frequency response differences of 0.4 dB at 16 kHz, but both were perfectly flat from 20 Hz to 8 kHz. In addition to me, Zipser, and Maki, one of Zip's friends, his wife, and another person unknown to me were sometimes in the room during the test, but no one was disruptive and conditions were perfectly quiet.
> 
> As far as I was concerned, the test was over. However, Zipser complained that he had stayed out late the night before and this reduced his sensitivity. At dinner, purchased by Zipser, we offered to give him another chance on Monday morning before our flight back North. On Monday at 9 a.m., I installed an ABX comparator in the system, complete with baling-wire lead to the Yamaha. Zipser improved his score to 5 out of 10. However, my switchpad did develop a hang-up problem, meaning that occasionally one had to verify the amplifier in the circuit with a visual confirmation of an LED. Zipser has claimed he scored better prior to the problem, but in fact he only scored 4 out of 6 before any difficulties occurred.
> 
> His wife also conducted a 16-trial ABX comparison, using a 30-second phrase of a particular CD for all the trials. In this sequence I sat next to her at the main listening position and performed all the amplifier switching functions according to her verbal commands. She scored 9 out of 16 correct. Later another of Zip's friends scored 4 out of 10 correct. All listening was done with single listeners.
> 
> In sum, no matter what you may have heard elsewhere, audio store owner Steve Zipser was unable to tell reliably, based on sound alone, when his $14,000 pair of class A monoblock amplifiers was replaced by a ten-year old Japanese integrated amplifier in his personal reference system, in his own listening room, using program material selected personally by him as being especially revealing of differences. He failed the test under hardwired no-switching conditions, as well as with a high-resolution fast-comparison switching mode. As I have said before, when the answers aren't shared in advance, "Amps Is Amps" even for the Goldenest of Ears.
> 
> Tom Nousaine
> Cary, IL





> *Richard Clark $10,000 Amplifier Challenge FAQ *
> 
> *by Tom Morrow *
> 
> *Written 6/2006
> *
> 
> The *Richard Clark Amp Challenge *is a listening test intended to show that as long as a modern audio amplifier is operated within its linear range (below clipping), the differences between amps are inaudible to the human ear. Because thousands of people have taken the test, the test is significant to the audiophile debate over audibility of amplifier differences. This document was written to summarize what the test is, and answer common questions about the test. Richard Clark was not involved in writing this document.
> *
> The challenge *
> 
> Richard Clark is an audio professional. Like many audiophiles, he originally believed the magazines and marketing materials that different amplifier topologies and components colored the sound in unique, clearly audible ways. He later did experiments to quantify and qualify these effects, and was surprised to find them inaudible when volume and other factors were matched.
> 
> His challenge is an offer of $10,000 of his own money to anyone who could identify which of two amplifiers was which, by listening only, under a set of rules that he conceived to make sure they both measure “good enough” and are set up the same. Reports are that thousands of people have taken the test, and none has passed the test. Nobody has been able to show an audible difference between two amps under the test rules.
> This article will attempt to summarize the important rules and ramifications of the test, but for clarity and brevity some uncontroversial, obvious, or inconsequential rules are left out of this article. The full rules, from which much of this article was derived, are available here and a collection of Richard's comments are available here.
> *
> Testing procedure *
> 
> The testing uses an ABX test device where the listener can switch between hearing amplifier A, amplifier B, and a randomly generated amplifier X which is either A or B. The listener's job is to decide whether source X sounds like A or B. The listener inputs their guess into a computerized scoring system, and they go on to the next identification. The listener can control the volume, within the linear (non-clipped) range of the amps. The listener has full control over the CD player as well. The listener can take as long as they want to switch back and forth between A, B, and X at will.
> 
> Passing the test requires two sets of 12 correct identifications, for a total of 24 correct identifications. To speed things up, a preliminary round of 8 identifications, sometimes done without levels or other parameters perfectly matched, is a prerequisite.
> 
> Richard Clark normally has CD source, amplifiers, high quality home audio speakers, and listening environment set up in advance. But if the listener requests, they can substitute whatever source, source material, amplifiers, speakers (even headphones), and listening environment they prefer, within stipulated practical limits. The source material must be commercially available music, not test signals. Richard Clark stipulates that the amplifiers must be brand name, standard production, linear voltage amplifiers, and they must not fail (e.g. thermal shutdown) during the test.
> *
> Amplifier requirements *
> 
> The amplifiers in the test must be operated within their linear power capacity. Power capacity is defined as clipping or 2% THD 20Hz to 10kHz, whichever is less. This means that if one amplifier has more power (Watts) than the other, the amplifiers will be judged within the power range of the least powerful amplifier.
> 
> The levels of both left and right channels will be adjusted to match to within .05 dB. Polarity of connections must be maintained so that the signal is not inverted. Left and Right cannot be reversed. Neither amplifier can exhibit excessive noise. Channel separation of the amps must be at least 30 dB from 20Hz to 20kHz.
> 
> All signal processing circuitry (e.g. bass boost, filters) must be turned off, and if the amplifier still exhibits nonlinear frequency response, an equalizer will be set by Richard Clark and inserted inline with one of the amps so that they both exhibit identical frequency response. The listener can choose which amplifier gets the equalizer.
> *
> 
> FAQs: *
> 
> *How many people have taken the challenge? *
> 
> Richard Clark says over a couple thousand people have taken the test, and nobody has passed. He used to do the test for large groups of people at various audio seminars, and didn't charge individuals to do the test, which accounted for the vast majority of the people who did the test. Around 1996 was the last of the big tests, and since then he has done the test for small numbers of people on request, for a charge ($200 for unaffiliated individuals, $500 for people representing companies).
> *
> When did the challenge start?*
> 
> Sometime around the year 1990. Richard Clark says in a post on 7/2004 that the test with the $10,000 prize started about 15 years ago.
> *
> What were the results of the test? *
> 
> Nobody has ever successfully passed the test. Richard Clark says that generally the number of correct responses was about the same as the number of incorrect responses, which would be consistent with random guessing. He says in large groups he never observed variation more than 51/49%, but for smaller groups it might vary as much as 60/40%. He doesn't keep detailed logs of the responses because he said they always show random responses.
> *
> Is two sets of 12 correct responses a stringent requirement? *
> 
> Yes. Richard Clark intentionally made the requirements strict because with thousands of people taking the test, even random guessing would eventually cause someone to pass the test if the bar was set low. Since he is offering his own $10,000 to anyone who will pass the test, he wants to protect against the possibility of losing it to random guessing.
> 
> However, if the listener is willing to put up their own money for the test as a bet, he will lower the requirements from 12 correct down to as low as 6 correct.
> 
> Richard Clark has said “22 out of 24 would be statistically significant. In fact it would prove that the results were audible. Any AVERAGE score more than 65% would do so. But no one has even done that”.”
> *
> Do most commercially available amplifiers qualify for this test, even tube amplifiers and class D amplifiers? *
> 
> Yes. Nearly all currently available amplifiers have specs better than what are required for the test. Tube amplifiers generally qualify, as do full range class D amplifiers. It is not clear whether Richard Clark would allow sub amplifiers with a limited frequency response.
> *
> Besides taking Richard Clark's word, how can the results of the test be verified? *
> 
> Many car audio professionals have taken the test and/or witnessed the test being taken in audio seminars, so there isn't much doubt that the test actually existed and was taken by many people. One respected professional who has taken and witnessed the test is Mark Eldridge. Because the test has been discussed widely on audio internet forums, if there were people who passed the test it seems likely that we would have heard about it. Sometimes there are reports of people who believe they passed the test, but upon further examination it turns out that they only passed the preliminary round of 8 tests, where levels were not matched as closely as for the final test.
> *
> How can audio consumers use the results of this test? *
> 
> When purchasing an amplifier, they can ignore the subjective sound quality claims of marketers. Many amplifier marketers will claim or imply that their amplifiers have some special topology, materials, or magic that makes the sound clearly superior to other amps at all volume levels. Many consumers pay several times more than they otherwise would for that intangible sound quality they think they are getting. This test indicates that the main determinant of sound quality is the amount of power the amplifier can deliver. When played at 150W, an expensive 100W measured amplifier will clip and sound worse than a cheap 200W measured amp.
> *
> Does this mean all amps sound the same in a normal install? *
> 
> No. Richard Clark is very careful to say that amps usually do not sound the same in the real world. The gain setting of an amplifier can make huge differences in how an amplifier sounds, as can details like how crossovers or other filters are set. When played very loud (into clipping), the amplifier with more power will generally sound better than a lower powered amp.
> 
> Most people perceive slight differences in amplitude as quality differences rather than loudness. The louder component sounds “faster, more detailed, more full”, not just louder. This perceptual phenomenon is responsible for many people thinking they liked the sound of a component when really they just liked the way it was set up.
> *
> I changed amps in my system to another one with the same measured power and I hear a sound quality difference. Does this show that the test results are invalid? *
> 
> No. Installing a new amplifier involves setting the gains and crossovers, and any slight change you make to those settings is going to affect how things sound.
> *
> Is adding an equalizer just a way of “dumbing down” the better amplifier ? *
> 
> Richard Clark allows the equalizer to be added to whichever amplifier the listener wants. It can be added to the amplifier that the listener perceives as the weaker amplifier . The EQ is most likely to be used when comparing a tube amplifier (which exhibits slight high frequency rolloff) to a solid state amplifier . In that case Richard Clark says he can usually fashion an equalizer out of just a resistor and/or capacitor which for just a few dollars makes the solid state amplifier exhibit the same rolloff as the tube amplifier, and therefore sound the same. If the tube amplifier really sounded better, then modifying the solid state amplifier to sound indistinguishable from it for a few bucks should be a great improvement.
> *
> How might allowing clipping in the test affect the results? *
> 
> It's impossible to know for sure because that would be a different test that has not been done. But Richard Clark seems to think that in clipping, conventional amplifiers would sound about the same, and tube amplifiers would sound different from solid state amplifiers.
> 
> Richard Clark reported that he did some preliminary experiments to determine how clipping sounds on different amplifiers . He recorded the amplifier output using special equipment at clipping, 12db over clipping, 18db over clipping, and 24db over clipping. Then he normalized the levels and listened. His perception was that with the same amount of overdrive, the conventional amplifiers sounded the same. With the same amount of overdrive the tube amplifiers sounded worse than the conventional amplifiers . On the basis of that experiment, he said “I believe I am willing to modify my amplifier challenge to allow any amount of clipping as long as the amplifiers have power ratings (actual not advertised) within 10% of each other. This would have to exclude tube amplifiers as they seem to sound much worse and it is obvious”.
> *
> If a manufacturer reports false power ratings, will that interfere with the test? *
> 
> No. The test is based on measured power, not rated power .
> *
> Does this mean that there is no audible difference between sources, or between speakers? *
> 
> No. There are listening tests that show small but significant differences among some sources (for instance early CD players versus modern CD players). And speakers typically have 25% or more harmonic distortion. Most everyone agrees that differences among speakers are audible.
> *
> Does the phrase "a watt is a watt" convey what this test is about?*
> 
> Not quite but close. Richard Clark has stated that some amplifiers (such as tubes) have nonlinear frequency response, so a watt from them would not be the same as a watt from an amplifier with flat frequency response.
> *
> Do the results indicate I should buy the cheapest amp? *
> 
> No. You should buy the best amplifier for your purpose. Some of the factors to consider are: reliability, build quality, cooling performance, flexibility, quality of mechanical connections, reputation of manufacturer, special features, size, weight, aesthetics, and cost. Buying the cheapest amplifier will likely get you an unreliable amplifier that is difficult to use and might not have the needed features. The only factor that this test indicates you can ignore is sound quality below clipping.
> 
> If you have a choice between a well built reliable low cost amp, and an expensive amplifier that isn't reliable but has a better reputation for sound quality, it can be inferred from this test that you would get more sound for your money by choosing the former.
> *
> Do home audio amps qualify for the test? *
> 
> Yes. In the 2005 version of the test rules, Richard explicitly allows 120V amplifiers in a note at the end.
> *
> How can people take the test? *
> 
> They should contact Richard Clark for the details. As of 2006 Richard Clark is reported to not have a public email account, and David Navone handles technical inquiries for him. Most likely they will need to pay a testing fee and get themselves to his east coast facility.
> *
> Is this test still ongoing? *
> 
> As of early 2006 , there have not been any recent reports of people taking the test, but it appears to still be open to people who take the initiative to get tested.
> *
> Do the results prove inaudibility of amplifier differences below clipping? *
> 
> It's impossible to scientifically prove the lack of something. You cannot prove that there is no Bigfoot monster, because no matter how hard you look, it is always possible that Bigfoot is in the place you didn't look. Similarly, there could always be a amplifier combination or listener for which the test would show an audible difference. So from a scientific point of view, the word “prove” should not be used in reference to the results of this test.
> 
> What the test does do is give a degree of certainty that such an audible difference does not exist.
> *
> What do people who disagree with the test say? *
> 
> Some objections that have been raised about the test:
> 
> 
> Richard Clark has a strong opinion on this issue and therefore might bias his reports.
> In the real world people use amps in the clipping zone, and the test does not cover that situation.
> Some audible artifacts are undetectable individually, but when combined with other artifacts they may become audible as a whole. For instance cutting a single graphic EQ level by one db may not be audible, but cutting lots of different EQ levels by the same amount may be audible. Maybe the amps have defects that are only audible when combined with the defects from a particular source, speaker, or system.
> Some listeners feel that they can't relax enough to notice subtle differences when they have to make a large number of choices such as in this test.
> There is a lack of organized results. Richard Clark only reports his general impressions of the results, but did not keep track of all the scores. He does not know exactly how many people have taken the test, or how many of the people scored “better than average”.
> If someone scored significantly better than average, which might mean that they heard audible differences, it is not clear whether Richard Clark followed up and repeated the test enough times with them to verify that the score was not statistically significant.
> *Is there one sentence that can describe what the test is designed to show? *
> 
> When compared evenly, the sonic differences between amplifiers operated below clipping are below the audible threshold of human hearing.
> 
> *Links *
> 
> 
> Full Rules of the Challenge dated May 25, 2005
> Richard Clark's comments on the challenge
> A carsound forum thread about the challenge, containing more comments from Richard Clark.
> 
> *Note from the author *
> 
> I wrote this Summary/FAQ because I found that many of the people who disagreed with Richard Clark about the challenge simply didn't have the whole story on the challenge. I originally thought the challenge was flawed even after I read the rules a few times, but after reading lots of comments from Richard Clark, my objections were answered and now I believe that understanding the challenge is a very useful tool for learning what is audible and what isn't. I have no relationship with Richard Clark and have never communicated with him except that I've read his public postings about the challenge. If anyone finds typos or factual errors in this document please contact me.


I have leaned towards the camp of not being able to hear any significant difference between almost any two amps out there when played at moderate levels on the typical speaker system, unless there is something wrong with one or the other amp that might cause it to color the sound. 

Granted... a low-end receiver may well have an issue driving a system of certain electrostatic speakers... or speakers with low sensitivity, especially if pushed to higher levels. There are going to be exceptions, but for the sake of this discussion, let's say we are using a pair of Klipsch RF-62 II speakers with a sensitivity of 97dB @ 2.83V / 1m ... or perhaps the Duntech Marquis speakers that Zipser was using above at 92db. 

I have owned processor/amp combos and/or receivers from Sony, Denon, Sunfire, McIntosh, Adcom, NAD, Onkyo, Earthquake, Anthem, Rotel, Lexicon, Emotiva (and probably others I cannot remember) powering Snell B-Minors, Klipsh Forte, PSB Image, SVS, JBL, Boston Acoustics, VMPS RM30's, MartinLogan Ascents, ML Spires and recently the older ML Prodigy mains with a Theater center and Ascent surrounds powered by Emotiva XPA-1's and an Onkyo 906 Receiver. Currently (updated January 2104) I run an Onkyo 5509 with an Emotiva XPR-5 with MartinLogan Montis, Stage X and Motion 12's. The most significant difference I ever heard was moving to the Martin Logan speakers. NOTHING had EVER made anywhere close to a difference in sound as did the MartinLogan speakers. I thought at one time that my NAD receiver had more of a soft sound (maybe "warmer" as some will state the description), but was told (never did verify it with NAD or via measurements) that NAD intentionally setup their receivers with a rolled off high-end. However, I have heard significant differences in speakers. I have also performed A/B testing between several amps and have not found any differences outside of clipping and/or distortion.

Is it not the desire of the audiophile to have electronic equipment which does not alter the sound?

Your thoughts and comments will be interesting.


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## atledreier

I have tried quite a few amps in my time too. 

And I must say I agree, as long as the amps are in their comfortable operating range, there is very little difference.


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## robbo266317

I'm showing my age again. 
Back in the 80's I built a 100 Watt per channel amp using the new wizbang MosFets, using the ETI 5000 kit, and a mate of mine wanted to compare it's sound with his new (expensive) amp/tuner.

So I made up an a/b switch box for the speakers and set amps to the same gain by measuring the volts across the loudspeaker with a 1 khz tone.

To me his amp was very muffled in the top end on classical music but hard to pick on standard pop/rock.
I know amplifier design has come a long way since and you would be unlucky to find any moderately priced amplifier which you could hear any problems with in an a/b comparison. I recently replacing the electrolytic's in my Mosfet amp and it still acquits itself extremely well.

There are more things to look at than simple frequency response and distortion measurements in equipment though. 
At around the same time, Nakamichi released their range of moving coil pickups for turntables with mixed reviews. Their engineers analysed the three groups of "Great", "good" and "poor" units.

What they found was the "good" group of devices had either a nice frequency response or nice phase response. 
The "great" ones had both a nice frequency AND phase response whereas the "poor" ones had both bad frequency and phase responses.

The same applies to speaker crossovers and keeping both frequency response and phase response smooth _should_ make an audible difference.

More recently another friend built a set of transmission line speakers and asked if I would like to listen to them whilst having a barbecue lunch. I of course agreed.

Knowing that Bob is a classical music man and I lean more towards rock I took along a Bruce Springsteen CD and we sat down to an afternoon of listening.

The speakers sounded good with the classical music however I complained about his left speaker when I played the Springsteen CD. He told me I was imagining things!
A few weeks later he phoned up and sheepishly said he had not cut the baffles for the grill cloth correctly and in the left speaker it was covering the midrange (male vocals) by about 80°.

These days I would spend more money on transducers than worrying that the amp was not up to scratch as the speakers are still the weakest link, followed by the crossover design.

Just my 2c


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## recruit

It will be the volume and power rating of amps that differ so some more powerful amps will drive speakers more easily and with difficult loads so just the volume levels will be higher, the difference in sound comes when using different processing/processors and the quality of the DAC's and pre-amp stage and processing chips.

I went from an Onkyo to the Arcam AVR600 and then the AV888 and SQ was taken to another level :T


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## tcarcio

I really think it has more to do with how you run the amps and connect the amps. If you have the same exact setup then at normal listening levels that do not strain either amplifier the sound is the same. It also means being used in the same room with the same ecoustics. I alway's think amps sound different in different places like either in the store or in my home theater, because to me they do.


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## Anthony

My experience with different amps has be believing that you can hear a difference, but it is mostly because of style and power supply. By style, I mean feedback, transistor type, etc.

I had an old Kenwood 6ch amp that had incredible distortion numbers, but a very high feedback design. It sounded harsh and fatiguing with anything containing high frequencies. Bass and midrange were very clean. 

I heard similar things from a digital switching amp (Class G/H, I think, not Class D).

I demo'd Parasound and Rotel amps and found them very neutral, but you could tell when you hit their limits, as the sound would audibly compress (an explosion or kick drum just didn't have as much pop). To be fair, these were their 85W/100W offerings, so I was likely playing them at the edge of their range.

I moved up to a Marantz receiver that had a clean, and neutral sound. No compression artifacts at higher volumes, but it didn't like the 4Ohm Magnepans, so I upgraded to an Outlaw 5ch amp and never looked back. Compared to all the other amps I tried, the Outlaw has a MASSIVE power supply (no dynamic compression) and is very clean (low, but not zero feedback design).

So there are differences in amps, due mainly to fact that none are ideal in power response, distortion response, etc -- even if their frequency response curve looks flat. And while I love my Outlaw amp, I bet Parasound, Rotel, Adcom, Krell, Emotiva, etc all have offerings that I would find indistinguishable from it.


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## torceador

Basically, I believe amps are commodity items. Now that I am 55 and have hearing loss above 13kHz, it's a very, very moot point for me. But when I was younger, before I did myself so much hearing damage, there was an amplifier comparison I could determine very well. It was the difference between Class-A type that had no crossover point, and Class-B type that did. Incidentally, it was at very LOW volumes where you could tell the difference. If you measured with an oscilloscope, you could tell there was a lot of coloration going on there in the Class-B. That's why, from very early on, amp measurements were made at high power levels, to minimize the percentage of crossover distortion in the total signal. (I can make my product look good if I think about HOW to measure it)

Newer models of hybrid A/B designs have active circuitry to speed the push-to-pull transition to the point that it is hard to measure, let alone hear. I still have a couple of old beloved Class A amps that I use from time to time, but they consume too much power even at rest to be environmentally responsible to leave them plugged in.

All that said, though, I am pleased that brushed aluminum, blue LEDs, weighted knobs, and ballast weight make amplifiers sound so much better. If it weren't for dissatisfaction there wouldn't be turnover. And without turnover, I wouldn't get newer stuff for cheap off of auction sites.

I hope anyone reading this that has 'higher SPL than the other guy' as a design goal would notice my statement above about hearing loss. If you fancy yourself a 'Golden Ear', remember Beltone doesn't make gold models.

torceador


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## eugovector

I would love to see some testing on distortion as well, an ABX on an amp pushing 1% distortion vs. 0.01% and see if folks can really tell the difference. I seem to recall article hypothesizing that you'd have to exceed 1% before most folks could hear the difference.

At the end of the day, I haven't heard a few amps, and I'll take some high quality speakers with a low-end amp any day, vs. HQ amp and LE speakers.


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## Anthony

Sadly it is a lot more complicated than that. Some amps have fairly constant harmonic distortion numbers, others vary wildly by frequency and output level (which can account for colorations in sound). Then there's which type of distortion.

I have tube amps that have horrible distortion numbers (even mode, though), and sound wonderful, despite the fact that they are "warming" the sound. 1/10th that in odd modes is harsh and grainy.

I used to have a program that would simulate distortion effects on any sound clip to let you experiment with perception and sound. Sadly that was two computers ago, so I have no idea where I could find it again. You were at the mercy of the test system (or headphones), but the relative changes were interesting to listen to. Based on what I remember, 1% was audible in SS amps, but 0.1 to .01 was very hard to tell a difference. 

Thankfully, manufacturers are backing off of the "spec wars" of the 80's and 90's, where they were using large amounts of feedback to get 1kHz power numbers with ultra low THD specs (at the expense of overall sound quality and dynamic range). A lot of companies were guilty of this -- it was easy to market. It wasn't until reviews starting testing all channels driven with full range signals that consumers (and eventually the amp manufacturers) wised up and started offering much better products.


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## tonyvdb

I think that "most" good quality amps that have real world ratings will preform well and like has been said sound very similar. I think the difference is in the build quality of the cheep companies. A $150 amp rated to put out 200 watts per channel is going to be far less capable at driving to full output and will distort than a manufacturer that uses good parts and over-sized capacitors will cost more but as the saying goes "you get what you payed for". 
If your comparing manufacturers that all use good parts I think it really depends on the type of speakers your using and even the receiver/source signal more than the amp its self.


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## fitzwaddle

If two amps test the same, in the same test conditions, I believe they would sound the same.

Clearly though, the introduction of a 5th foot on the new Yamaha AVRs represents a significant auditory breakthrough. :sarcastic:

http://www.hometheatermag.com/images/newsart/080610yamaha.jpg

(prepares for the onslught of 5th foot devotees)


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## Anthony

fitzwaddle said:


> http://www.hometheatermag.com/images/newsart/080610yamaha.jpg
> 
> (prepares for the onslught of 5th foot devotees)


Only if the 5th foot is colored by a special green marker -- otherwise it is suboptimal :bigsmile:

(for those who weren't hoodwinked in the 90's: http://aroundcny.com/technofile/texts/greenink86.html)


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## fitzwaddle

Hahaha, I had forgotten about that. Surprised noone has advocated putting a pyramid over your receiver too, or maybe a receiver sized "power band" bracelet.

http://www.powercoreband.com/?gclid=CMqni7ep0KQCFYjt7QodDjPcCA


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## RBTO

Going back to your question about changing a 1kHz tone, there can be many different 1kHz "tones" since a tone doesn't specify the waveform (e.g., 1kHz squarewave, 1 kHz wind instrument note, etc., etc.) However, you cannot change a 1kHz sinewave without changing it into something else. Why am I blithering about this? It relates to what one poster mentioned and that's harmonic distortion. Different amplifiers can have different amounts of harmonic distortion which is one of the primary differences between amplifiers of different vintages. As of late though, amplifiers are being manufactured which have very low levels of harmonic distortion - so low in fact that it would be almost impossible to hear amplifier distortion with the ear.

I can fully accept both of the original quotes and believe in many cases, unless the amplifiers are badly matched, no differences are audible between competing amplifiers. As one poster stated, it becomes more a matter of things external to the amplifier (speakers, wiring, etc.) for audible differences to exit, and under test conditions where these are minimized, not too many folks would be able to tell when an amplifier has been switched out with another, unless the second has ratings in the basement compared to the first.

I've never accepted that a high priced amplifier is worth its value solely in terms of sound quality (there might be other factors to consider such as construction & durability). That is more true these days than ever. For those that can't afford the $100K amplifier, don't pine at what you are missing!!! Take solace in that your $2C (that's $200 for those that don't know the Roman numerals) amplifier, if purchased more recently, can and probably does sound just as good as that high priced one under listening conditions most people enjoy.


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## Anthony

To get back on topic, though, I have access to a really nice O-scope at work and have been meaning to test my Outlaw amp, among others. I just haven't had the time. I really respect the reviewers/websites/magazines that check all the specs of every product.


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## Jim Holmes

Perhaps my observations have no relevance to this thread due to the fact that my experience was in professional audio applications but I know when I was doing live sound production with arena sized PA systems there was a big difference in the sound of different amplifiers of similar output. The PA company changed its brand of amplifiers four times on the same speaker system in a three year period. The first set of amps were a conventional power supply type with a very warm and musical tone however they were large and heavy and were power hungry. Competitors came forth with switching power supply amps that were lighter and more power efficient but the tone of the amps was shrill in the high frequency range and they could not reproduce the envelope of the note of a kick drum completely. The owner had purchased them without giving them a listen first. These amps were quickly replaced by another brand which had similar issues although they did sound a little warmer. The fourth replacement was good as this brand had excellent tone and could reproduce bass notes effectively. 

Three observations I made throughout this ordeal was first, the amplifier needs to be able to store or access enough current to comlplete the entire envelope of a low bass note. Second, it must be able to exhibit good control over the transducers it is driving to give proper transient response. Third, the amp must not add odd order harmonics to the fundamental high frequencies or it will sound shrill and color the sound. 

That being said, I recently purchased a large seven channel surround amplifier to replace some pro A/B type two channel amplifiers with a slightly higher power output but the seven channel amp is a dual differential balanced design and even with less power it sounds much cleaner with tighter bass and more accurate reproduction on the same speaker system.

I therefore conclude that not amplifiers sound the same nor do they sound the same in the same brand.


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## Jungle Jack

Hello,
I have never personally noticed a massive difference with the exception of Tube Amplifiers. The issue with Level Matching is not all Amplifiers are capable of outputting at the level. 

My Aragon 8008bb and HCA-3500 both are capable of huge amounts of power thanks to having over 2.0 kVA Toroidal Transformers and over 150,000uf of Capacitance. This is the same Power Supply as my 5 Channel HCA-2205AT that is considered one of the most powerful Multichannel Amplifiers available without a Fan.

Having a fan really can make an audible difference. Especially many Pro Amps have them as they are designed with Rack Mounting in mind and are not usually if ever near Recording Areas. In an HT, this can be an issue.
Cheers,
JJ


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## eugovector

Jungle Jack said:


> Having a really can make an audible difference. Especially many Pro Amps have them as they are designed with Rack Mounting in mind and are not usually if ever near Recording Areas. In an HT, this can be an issue.


Incomplete thought, I'm guessing "fan".


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## Jungle Jack

D'oh. I am Posting on my Macbook that has multiple Key's not working. I have to Cut and Paste the Letters h,y, and the number zero every time I write words containing said Letters. It was indeed fan I intended to write. This is not easy to write Posts. Truly an Ice Cream Cone to Forehead feeling while doing so. And the Delete Button is broken.
Cheers,
JJ


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## eugovector

Sounds like you need to borrow a USB keyboard


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## Jungle Jack

Excellent idea. I was going to scrap it, but makes a great deal more sense.
JJ


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## fitzwaddle

Jim Holmes said:


> I therefore conclude that not amplifiers sound the same nor do they sound the same in the same brand.


I don't think the premise was that all amplifiers sound the same - rather, that any two amps that measure the same, under the same measurement conditions, should sound the same. I.e. there isn't some other ethereal / unmeasurable property that gives amps "character".


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## DrAudio

Hey all - been awhile since I posted up. Been busy moving and changing jobs and whatnot. 

I'm glad this question came up. In my opinion it's actually very interesting. Similar to the typical can you tell cable differences/equipment (physical) grounding, and all the other jazz.

I initially tried to write my dissertation on this same question although my methodology was actually going to be scientific rather than survey, listening tests, etc.. There are ways of measuring differences in the auditory system in the brain and are done very regularly using electrophysiologic tests. They can measure differences early on or late in the system depending on where you want to look in the process. 

I think it'd be really cool for an equipment manufacturer or one of the stereo magazines to sponsor something like this. It would provide really interesting information and actually scientifically ground some of these often debated questions.

-D


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## mdrake

This is very interesting topic and one that stirs a lot of debate. I have never attempted blind testing two amplifiers but I would find it really interesting to do a blind test between a valve and solid state amp. 

Matt


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## Josuah

Yes, I can hear differences between amplifiers. I characterize those differences in clear terms like distortion or response time (i.e. not just warm or detailed). The simple set of measurements usually provided with audio gear is insufficient; a larger set of measurements is better but often not done or at least not published. The audible differences I have clearly identified in my own testing are differences that I believe can be measured, and I have some expectation of what those measurements would look like.


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## recruit

I went from an Onkyo 905 AVR to a pre/pro set up and the amps inside the Onkyo were very good, it was only when playing at very loud levels that I could tell the difference, the Onkyo strained and the sound hardened and became a little too uncomfortable to listen where as the Rotel 1575 did not when pushed harder and was easier on the ear.


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## sub_crazy

This is an interesting discussion.

I do think it is very hard to tell a difference in amps unless you can do a comparison at home at the SAME TIME. I once did a comparison of 6 or more different amps I had in my rack at one time with the help of a friend. 3 of them sounded very similar and we had to nit pick which we liked better, 2 others had the same dry quality to the sound which made them sound dull to me and 1 was horrible compared to the others. These were all high end names from Classe, Aragon, Krell, EAD, ADA, Parasound and Sunfire. I had my list of favorites which differed from my friends list but the similar sounding ones were all in the top 3 on both our lists.

I think a great amp is just that, it should not add anything but what is on the recording. An amp can only damage the signal so the better ones just have less flaws IMO.

I have tried a lot of amps over the years and even some which are HIGHLY regarded which I hated. I am now back to the amp that does the least damage in my system which I regretfully sold but found again.

I am pretty much saying that in my system my amp does the least damage to the signal than all the others I have tried.


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## lcaillo

I agree with draudio that we need to address the question scientifically. Now many on the purely objectivist side will say that this has been done. In my opinion it has not been done from a truly objective and scientific perspective. We know a lot about reproducing sound, a lot about how amps work, and a lot about the psychological and physiological aspects of perception. What we have not done is addressed in a systematic manner the reasons that people hear what they do. While the vast majority of differences of many types can be explained by placebo, expectation bias, and other "soft" variables, there are also some clear possibilities for differences to exist in the hardware.

The question that we need to address is why people hear what they do, searching for explanations systematically. This involves more than just showing no difference in ability to identify amps in ABX blind testing. There are so many variables that this does not explain that the results are simply not that interesting. For instance, a constant theme in many of the more reasonable comments here is that amps have to be operating within their nominal range to assume little or no difference. Many years of experience have demonstrated to me that this is often not the case when people do experience differences. What are the parameters that matter? How do we identify them in the field with such high variability in loads, source material, and system design? How should we test amps to reflect more closely how they will be used? What parameters matter most when dancing around this assumption that amps are operating within their range of ability? How do we identify differences that might exist? What is there that matters beyond obvious clipping, THD, IM, and noise? All of these are good questions that have only been barely touched as far as reasearch and reporting goes.


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## terry j

key words...operated within limits, not clipping.

I'd bet almost any money people clip their amps far far more than they ever realise.

Then you can tell a difference between a valve and ss amp. but only because it is clipping.


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## Anthony

Leonard, you bring up a good point about not knowing everything about the perception of sound.

Used to be that everyone said humans could only hear to 22kHz or so, so amps and speakers just cut off at that point (or thereabouts) without much worry. I read an article about harmonics a few years back that studied how we can hear detail up to 44kHz, even though we can't hear a pure sinewave tone at that frequency. It has to do with the transient response and how more transient (step function) waves are more like a summation of a fundamental + many harmonics. The more harmonics that are added in, the "crisper" the edge of the waveform. Mathematically, this is known as a Fourier series. 

But if the amps and speakers can't reproduce those frequencies, the sharp edge of that square wave (or plucking guitar string, or drum hit) gets rounded and the transient response is altered somewhat.

So how we perceive this, how transient and high frequency response is affected by distortion, etc, etc, is still not fully characterized.

That all being said, if the amps measure EXACTLY the same, then you wouldn't be able to tell the difference -- I just don't think that's possible yet.


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## Moonfly

What an interesting subject, and debate!

Over the years Ive found it pretty much impossible to distinguish the difference between 2 similarly spec'd amps, and not been all that sure about the differences between quite differently priced amps. Maybe its just my listening levels, not sure, but I'm quite happy to settle on that result personally. I'm fairly happy with my Onkyo and its amps do a perfectly fine job for my speakers. I would upgrade it once I have speakers that might benefit, but I would go silly.

I certainly think money is better pushed on speakers you like, then simply put n amp with it that will drive them well. As recruit has pointed out, I think the more important area is the processing etc, especially in HT setups, and more so in HT setups that need to double a the main music system as well.


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## JerryLove

lcaillo said:


> We know a lot about reproducing sound, a lot about how amps work, and a lot about the psychological and physiological aspects of perception. What we have not done is addressed in a systematic manner the reasons that people hear what they do.


 Actually: We've concretely established that people hear exactly the same thing because two properly built and not-overdriven amps are identical in output to a specificity higher than human hearing.



> While the vast majority of differences of many types can be explained by placebo, expectation bias, and other "soft" variables, there are also some clear possibilities for differences to exist in the hardware.


 Which, on properly built amps not driven to clipping have been clearly eliminated time and time again by blind comparisons.



> Read more: Can we really hear a difference between amps? - Page 3 - Home Theater Forum and Systems - HomeTheaterShack.com


No. We cannot. Unless at least one amp is being over-driven or is improperly built (adds coloration). That's been proven time and time again by testing.


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## Sonnie

Do you know of specific tests that have been done that are recorded on the web... maybe links to them or maybe we can copy and paste a few of them here for added discussion.

It seems evident that there are indeed tests that have proven there is _no_ difference, but I have never seen any tests that show there _is_ a difference... and I suspect there are none, but more tests would be interesting to read.


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## JerryLove

http://www.roger-russell.com/truth/truth.htm#goodamplifiers

In addition to his own expereinces testing, he references testing by Ian Masters in the January 1987 issue of Stereo Review, as well as a test conducted at the 2006 Rocky Mountain Audio Fest and written up in the February 2007 issue of audioXpress magazine.

Also High Power Amplifiers by Julian Hirsch Stereo Review November 1992.


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## Sonnie

Thanks... there is a lot of good reading on that link. :T


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## Moonfly

Sonnie said:


> Thanks... there is a lot of good reading on that link. :T


Seconded :T


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## bassman_soundking

I am not sure if we are talking about just home audio and pro amps? I have definitely noticed a difference in amps before when speaking of car audio (I have had a slew of car audio amps). The only difference that was clearly audible was when I was running Linear Power brand amps. The sounds was (without sounding like a fan-boy) all those cliche attributes. The bass esp. was extremely articulate. I have used and currently do amps that are way more powerful, but dont have the same quality of bass at any volume level. I never believed there was honestly a real world difference before, nor have I experienced one since. LP amps use TO-3's, and have a relatively high damping factor, is this the difference...I dont know. I still have one of the LP amps in a closet for a rainy day (2502 IQ).


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## JerryLove

bassman_soundking said:


> I am not sure if we are talking about just home audio and pro amps? I have definitely noticed a difference in amps before when speaking of car audio (I have had a slew of car audio amps). The only difference that was clearly audible was when I was running Linear Power brand amps. The sounds was (without sounding like a fan-boy) all those cliche attributes. The bass esp. was extremely articulate.


 There are several options. 
1) It's imagined. Let's just assume it's not imagined because we'd need a DBT to determine if it was.
2) The other amps are underpowered (please remember that blatant lies regarding power are rife in the audio amp world). Realistically, a very good car amp might be 25WPC.
3) There's EQ occuring in the amp you like.


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## bassman_soundking

JerryLove said:


> There are several options.
> 1) It's imagined. Let's just assume it's not imagined because we'd need a DBT to determine if it was.
> 2) The other amps are underpowered (please remember that blatant lies regarding power are rife in the audio amp world). Realistically, a very good car amp might be 25WPC.
> 3) There's EQ occuring in the amp you like.



((The other amps are underpowered))

((There's EQ occuring in the amp you like))

These are possibilities....and I know Rockford Fosgate for sure adds like 2-3 db boost in their amps, or at least did in the past (so other companies might as well).

I run an amp in my car now that is wayyyyyyy more powerful than the LP though and while is gets extremely loud it doesnt have the best sq. 600 rms rated LP...and 4k rms measured and ratedfor the Autotek MM4000.1

I honestly did run different sub(s) on the Autotek as I dont own the subs That were played on the LP amp anymore. I mention the Autotek because this is the most powerful amp I have ever owned and can say for sure now that the LP didnt sound better as a result of more power. I did run those subs on several amps although and sounded the same with the one exception.
Other amps run...Alpine, Autotek, Rockford Fosgate, Sound Stream, Infinity, Clairion, Zapco, Polk Audio, The Hott Setup, Jensen, Optimus, Sony, Pioneer, MMats, Precision Power.....and others as well. Other than one is louder than another never really a memorable difference in sound. Some were very very reliable some not some run cool some hot...But same basic sound.


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## Lucky7!

Sonnie said:


> Is it not the desire of the audiophile to have electronic equipment which does not alter the sound?
> 
> Your thoughts and comments will be interesting.


LOL Sonnie, the Zipser test is my fave example of the DBT working correctly. I also agree that the gear ideally will impart no signature at all on the signal passing through it, unless it is meant to, eg EQ.

My current position, based upon many years of designing, building, modifying and servicing a lot of amplifiers of probably every type is that there should be no audible differences between well made units, operating within their specifications. If there is, the unit was not designed well or the perceived colouration intentional on the part of the designer.

As I am not much of a fetishist over brands, I simply want to know if it will perform as I need it to reliably. Many years ago however, I spent a lot of time even testing parts in the amps I designed; would brand A resistor/cap sound better than brand B in this position or that and I tried many permutations of parts as well as topologies. It was not unusual to have as many as a dozen stereo amplifiers on my floor at one time. Because I changed them in/out so often I made a standard connector arrangement for them all so it was one step to change between them. One night after many hours I'd done the last bit of testing and thought I'd made the best amp so far, left it on to soak and went to bed. Next day I listened to some music over breakfast, then went to turn off the 'best' amp to permanently solder in some parts; the music kept playing. I had mistakenly connected in my old mule amp a modest SS Rotel, not the great tube amp I thought I had been listening to for the last couple of hours before bed.

After that I did a lot of testing by close level matching and switching to test myself. Amazingly obvious differences were suddenly not something I'd bet a dollar on. To be sure it wasn't my hearing, I tested others who were sure they could tell differences between just about everything. No one picked such things as a 30yo SS Marantz integrated over a Fisher tube amp for example (I had very efficient speakers with an even Z curve so no real issues there). There were many others too, so it reinforced to me how much our visual perception and preconceived ideas play in what we think we hear.


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## bassman_soundking

A9X said:


> LOL Sonnie, the Zipser test is my fave example of the DBT working correctly. I also agree that the gear ideally will impart no signature at all on the signal passing through it, unless it is meant to, eg EQ.
> 
> My current position, based upon many years of designing, building, modifying and servicing a lot of amplifiers of probably every type is that there should be no audible differences between well made units, operating within their specifications. If there is, the unit was not designed well or the perceived colouration intentional on the part of the designer.
> 
> As I am not much of a fetishist over brands, I simply want to know if it will perform as I need it to reliably. Many years ago however, I spent a lot of time even testing parts in the amps I designed; would brand A resistor/cap sound better than brand B in this position or that and I tried many permutations of parts as well as topologies. It was not unusual to have as many as a dozen stereo amplifiers on my floor at one time. Because I changed them in/out so often I made a standard connector arrangement for them all so it was one step to change between them. One night after many hours I'd done the last bit of testing and thought I'd made the best amp so far, left it on to soak and went to bed. Next day I listened to some music over breakfast, then went to turn off the 'best' amp to permanently solder in some parts; the music kept playing. I had mistakenly connected in my old mule amp a modest SS Rotel, not the great tube amp I thought I had been listening to for the last couple of hours before bed.
> 
> After that I did a lot of testing by close level matching and switching to test myself. Amazingly obvious differences were suddenly not something I'd bet a dollar on. To be sure it wasn't my hearing, I tested others who were sure they could tell differences between just about everything. No one picked such things as a 30yo SS Marantz integrated over a Fisher tube amp for example (I had very efficient speakers with an even Z curve so no real issues there). There were many others too, so it reinforced to me how much our visual perception and preconceived ideas play in what we think we hear.


I am glad someone has a different view than I do and says so in a very tactful manner, and I honestly after all these years can admit that maybe it was thought to sound better and now want to do more A/B blind testing with the amp I have heard the differences in. I will need to repair the amp to do so.....new project.


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## lsiberian

I think a new amp always sounds better than an old one unless the new amp is uglier than expected. But that's probably from the euphoric feeling of having the new amp.


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## bassman_soundking

lsiberian said:


> I think a new amp always sounds better than an old one unless the new amp is uglier than expected. But that's probably from the euphoric feeling of having the new amp.


Haha, yeah new amps r great. And the euphoric feeling cant be compared, unless to a new monitor or projector.


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## Moonfly

A9X said:


> There were many others too, so it reinforced to me how much our visual perception and preconceived ideas play in what we think we hear.


I think this is a big deal. This had been documented in other fields, such as visual perception, and in that field its easy to show others how perception is a big part of what we actually see. The below video illustrates the point perfectly. I'm certain the same thing happens with our ears to a degree, its just infinitely more difficult to show it so inarguably.


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## lsiberian

Moonfly said:


> I think this is a big deal. This had been documented in other fields, such as visual perception, and in that field its easy to show others how perception is a big part of what we actually see. The below video illustrates the point perfectly. I'm certain the same thing happens with our ears to a degree, its just infinitely more difficult to show it so inarguably.
> 
> www.youtube.com/watch?v=Ttd0YjXF0no


Honestly I do think looks matters. I don't want an ugly amp no matter how good of a deal it is. At the end of the day reliability is king though. If something breaks my system is down and that sounds more terrible than the noisiest of amps.


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## gsmollin

I've been through this thread ad-nauseum over at the AVS forum, and of course it always got nasty. So without getting nasty, I will explain why people continue to hear differences between amps, yet in controlled tests there is little or no difference.

As long as modern, solid-state, linear power amplifiers are operating within their linear levels, the differences are so small that they can only be measured, and not heard. The problems and differences arise when they are overdriven. Then almost every amplifier-loudspeaker combination you can put together will respond with its own sound. In most controlled tests, levels are kept low so that there is no clipping/overdriving to hear. But if the volume were turned up, then Zipper would have heard a difference. Actually, everybody would have heard it. It takes only a small increase in the levels to drive an amp into overload. A 3 dB change in volume is barely perceptible, but is double the power, so it's a big deal to the amp. 

That's it in a nutshell. As a adder, the overload characteristics of tube amps are rather different from solid state, and are ususally more gradual. This is most of what tube amp sound is about, although that's not all of it.


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## bassman_soundking

gsmollin said:


> I've been through this thread ad-nauseum over at the AVS forum, and of course it always got nasty. So without getting nasty, I will explain why people continue to hear differences between amps, yet in controlled tests there is little or no difference.
> 
> As long as modern, solid-state, linear power amplifiers are operating within their linear levels, the differences are so small that they can only be measured, and not heard. The problems and differences arise when they are overdriven. Then almost every amplifier-loudspeaker combination you can put together will respond with its own sound. In most controlled tests, levels are kept low so that there is no clipping/overdriving to hear. But if the volume were turned up, then Zipper would have heard a difference. Actually, everybody would have heard it. It takes only a small increase in the levels to drive an amp into overload. A 3 dB change in volume is barely perceptible, but is double the power, so it's a big deal to the amp.
> 
> That's it in a nutshell. As a adder, the overload characteristics of tube amps are rather different from solid state, and are ususally more gradual. This is most of what tube amp sound is about, although that's not all of it.


I agree some ppl have the ability to disagree in a poor manner, glad u r not one of them :T
Nice response also, I agree different amps can clip differently.


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## recruit

I have had Lexicon / Parasound / Meridian / Chord & Rotel power amps in my set ups and tbh it was only when they were pushed hard did you get to notice any changes in sound and that was distortion in some cases when pushed too hard, even some AVR amps will only differ in volume output from my experiences with them, it is more to do with the processing / preamp and DAC stages that will make the sound differ.

So I feel money is better spent elsewhere in your system ie source components and also pre-amp and processors rather than thousands on a more costlier power amp.


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## Lucky7!

gsmollin said:


> As long as modern, solid-state, linear power amplifiers are operating within their linear levels, the differences are so small that they can only be measured, and not heard. The problems and differences arise when they are overdriven. Then almost every amplifier-loudspeaker combination you can put together will respond with its own sound. In most controlled tests, levels are kept low so that there is no clipping/overdriving to hear. But if the volume were turned up, then Zipper would have heard a difference. Actually, everybody would have heard it. It takes only a small increase in the levels to drive an amp into overload. A 3 dB change in volume is barely perceptible, but is double the power, so it's a big deal to the amp.


If the amp audibly overloads in normal use it's too small.

As for the audibility of short duration clipping, here is Bob Cordell's experiment. If it was audible most of the flea power tube systems could only be listened to a whisper levels.

Regarding the hypothetical of whether Zipser test was too low, email Tom Nousaine and ask. There is a 3dB rating difference between the two amplifiers.

Also regarding the point of it being only clipping behaviour that determines the audibility, I have been involved in a couple, as well as my own SBT of amps of similar power. If one were adding a sonic characteristic because of clipping, it should have been apparent, yet wasn't.



gsmollin said:


> That's it in a nutshell. As a adder, the overload characteristics of tube amps are rather different from solid state, and are ususally more gradual. This is most of what tube amp sound is about, although that's not all of it.


Modern tube amps with NFB overload in much the same way and degree as SS amps, plus as many are cap coupled there is strong potential for blocking and slower recovery.


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## JerryLove

gsmollin said:


> In most controlled tests, levels are kept low so that there is no clipping/overdriving to hear. But if the volume were turned up, then Zipper would have heard a difference. Actually, everybody would have heard it. It takes only a small increase in the levels to drive an amp into overload.


 Your math is certainly correct: power doubles ever 3db, but it reminds me of the old saying "I get drunk on one beer... usually about the tenth one."

I don't believe your claim that most DBT's are at a" low" volume, which is to say that, in my experience, the bulk of DBT testing is done at the preferred volume of the listener. Put simply: if you are clipping then you have too small an amp.

You are right that amps driven to failure fail differently. You are wrong in your apparent inference that reasonable volumes neccesaitate failure. A properly chosen amp-speaker pair should not hit audible distortion, nor should it clip. Clipping and THD should be non-issues in both a DBT and actual use of your amp-speaker rig. If they are issues, then you've chosen the wrong amp for your application.

Note: the above applies to music *reproduction*. In music *production* it's not uncommon to deliberately drive an amp to distortion because of a desire for the distorted noise. An electric guitar amp may be set at "10" (or "11") and the gain on the guitar set high, particularly with a tube-stage, to make a distinctive sound (BTW: this can be emulated in software as well: actually running distortion is not neccessairy)


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## goyop

I believe some of the confusion in this area is in partly due to people thinking "system" when others are speaking of a discrete component called a power amplifier. Jerry is correct saying that two amps that have the ability to produce a similar amount of output power are going to sound the same. And if there is distortion then the amp/system is undersized or set up wrong.

The caveats within the power amp are, as mentioned by others, is there enough capacitive storage in the power supply to cover low end demands. But that gets right back to Jerry's comment that if it is not underpowered then it will not distort.

So based upon designing amps, using amps, listening to untold number of amps I can conclude that equally powered amps are going to sound equal assuming that there is no distortion due to the amp design. That means that the THD or measureable distortion is within acceptable limits. One way to think of it is that a power amp takes a signal, sine wave or music, and simply takes it from a one volt wave to one that is much larger in size. The amp simply multiplies what comes in and sends out an "exact" match but much taller. If both amps do this without coloring (adding unwanted EQ) or clipping then they will sound the same. As one person said, the amp is a commodity. Some are built with better components and last longer. A pure power amp is such a basic simple design that there is not much difference between them. There are different "types" of circuits used to make power amps but they really are a commodity now meaning that all decent amps do the same thing.

So in an A/B situation swapping only the amp there would not be any audible difference as demonstrated by all the examples given in this thread.

If one is to start thinking of systems and EQ and impedance and matching then there is not enough time or forum space to compare them.


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## sub_crazy

recruit said:


> I have had Lexicon / Parasound / Meridian / Chord & Rotel power amps in my set ups and tbh it was only when they were pushed hard did you get to notice any changes in sound and that was distortion in some cases when pushed too hard, even some AVR amps will only differ in volume output from my experiences with them, it is more to do with the processing / preamp and DAC stages that will make the sound differ.
> 
> So I feel money is better spent elsewhere in your system ie source components and also pre-amp and processors rather than thousands on a more costlier power amp.


I agree with you recruit that pre-pro's make a much bigger difference in SQ than a well designed amp. 

Any amp that *Does Not Harm* the signal should sound the same.


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## rosco968

The trouble is, all amps harm the signal. I think this is why there is a difference between so many amps. The difference may not be huge or it may be pronounced, but I think amps sound different.


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## JerryLove

rosco968 said:


> The trouble is, all amps harm the signal. I think this is why there is a difference between so many amps. The difference may not be huge or it may be pronounced, but I think amps sound different.


 This is true. All amps distort soun and the distortion efffect is not likely to be uniform. Amps have a published spec regarding how much distortion they create. For most any amp worth discussing, it is less than .1%. That is far below human hearing.


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## sub_crazy

rosco968 said:


> The trouble is, all amps harm the signal. I think this is why there is a difference between so many amps. The difference may not be huge or it may be pronounced, but I think amps sound different.


That's true, I should have said *Does the Least Harm*


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## gsmollin

Thanks for the replies to my post about amplifier overload. Overloading an amplifier is not a simple matter. The load is a complex electromechanical device, the source material can contain pathological signals, and amplifiers almost all have self-protection circuits that distort the signal when they are tripped.

I have a number of speaker impedance curves, and at least one premium brand 8-Ohm speaker has a dip to less than 3 Ohms at the crossover between woofer and midrange, at about 400 Hz. Connect that speaker to an amplifier not rated below 6-Ohms, and send a signal with a strong 400 Hz component, and the system will suddenly distort. This can be heard, but one will have a hard time pinning it down, because the amplifier has to be hit with the bad combination. Nevertheless, if and when this sort of thing happens, the careful listener will hear "A difference in the amplifier". It's not that simple, but it is also true that an amplifier change may break up the bad combination and the new amplifier will "sound different". I know a lot about this incident because it happened to me, and I tracked down the sources of the problems. I would say that the speakers were more to blame than the amp, but everyone knows that if you change the speakers your system will sound different, and they are probably right. With the amplifier it's not so straightforward, and gives rise to threads like this.


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## rosco968

Do you also think that all DACs sound alike as well? I just wonder where the line is drawn in this question??


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## JerryLove

rosco968 said:


> Do you also think that all DACs sound alike as well? I just wonder where the line is drawn in this question??


 Perhaps you should start a thread on that question rather than ask it on this one.


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## Sonnie

Agree... :T


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## Moonfly

rosco968 said:


> Do you also think that all DACs sound alike as well? I just wonder where the line is drawn in this question??


I think there is a lot more feeling that processor make a fair bit of difference in a setup, and I for one lean that way. I agree, starting a thread on that subject would be very interesting.


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## recruit

Moonfly said:


> I think there is a lot more feeling that processor make a fair bit of difference in a setup, and I for one lean that way. I agree, starting a thread on that subject would be very interesting.


The quality as a whole unit will depend on how a processor sounds, so it will be the pre amp stage DAC's and also the processors that will determine how it sounds, the pre amp stage is superb on my Arcam allowing my CD players full potential to be heard, and then the DAC's for my digital inputs (HDMI) also make a big difference and luckily Arcam have taken into account the amount of jitter that HDMI can cause, virtually eliminating it therefore making a better sound, then there is the latest SHARC processing which will also make a difference...anyway best left for another thread...but you get my drift :nerd:


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## rosco968

The only reason I ask it hear is because I think most people would agree that the circuit design and different components in a DAC make a difference in the sound and I wonder why the same wouldn't be true for an AMP?


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## Moonfly

rosco968 said:


> The only reason I ask it hear is because I think most people would agree that the circuit design and different components in a DAC make a difference in the sound and I wonder why the same wouldn't be true for an AMP?


A processor not only has that, but it also has on board software that intentionally augments the signals as they pass through. Simply hitting a DSP mode is a huge example of this kind of thing.


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## rosco968

I am not talking about a processor. I am talking about a DAC (digital to analog converter). There is no software...just a process that affects the sound.


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## recruit

rosco968 said:


> I am not talking about a processor. I am talking about a DAC (digital to analog converter). There is no software...just a process that affects the sound.



Yes, there are many types of DAC's and some are at the low end of the mainstream AVR's and then you have the top of the range ones, Wolfson and Burr Brown come to mind, some will accept DSD from SACD and others will not, it is all down to there sampling rate and there are 24bit and some 32bit but it is not to say that the 32bit DAC is better, there is loads of white papers on DAC's and most of it will go straight over our heads for us mere mortals, here is an example to Digest...

http://www.wolfsonmicro.com/products/dacs/WM8741/


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## Moonfly

rosco968 said:


> I am not talking about a processor. I am talking about a DAC (digital to analog converter). There is no software...just a process that affects the sound.


I appreciate that, but for many (I would argue the majority), the DACS are tied into a processor of some kind, and that the processor is a big variable in that. John makes some better points on the specifics of DACs too though, and he is probably the better person in that subject. I suppose a good test would be a setup comprising of the same amp(s), speakers and source, with stand alone DACs placed in the loop that could be swapped out?

I feel a new thread or two coming on already :nerd:


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## JerryLove

rosco968 said:


> The only reason I ask it hear is because I think most people would agree that the circuit design and different components in a DAC make a difference in the sound and I wonder why the same wouldn't be true for an AMP?


 It's testable the same way amps are testable. Put given waveforms in and compare the output for differences. Quantify and then qualify those differences to determine if they are audable. 

The good news is, moreso than sounic waves in the air, electrical waves in a conduit are relatively absolute things (for the purpose of powering a speaker).

One could also try the ever-popular DBT method to remove theory from practice.


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## Joe in Seattle

I used to be convinced that I could. For instance I chose a Yamaha RXV 2095 over an identically powered Yamaha receiver because the one sounded better driving Martin Logan Speakers. They sounded roughly the same driving less challenging speakers.

I introduced a partially deaf friend to my hobby years ago. He was delighted to listen to my stereo because, even with his limitations, he could hear sounds/music more clearly at my house. That was in the days of a Pioneer Reciver and Speakerlab kit speakers I built myself.

I'm finding these days, at 64, that my aural acuity isn't what it once was, but I can still tell the difference between a good system and a bad one. I doubt my ability to tell the difference between amplifiers - save possbily the comparison between a tube amp and a transistor-based one.

It's all fun, though.


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## gdstupak

As asked in the original post, the answer is 'no' you cannot hear a difference between amps.
But in reality most all amps have some coloration of sound whether intentional or not.
Hearing a difference between amps depends on their coloration characteristics and if you know what to listen for. 2 amps that color sound the same way will sound similar. 2 amps that color sound in different ways will sound different.
So I think the answer is 'yes' and 'no' here in the real world.


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## Moonfly

gdstupak said:


> As asked in the original post, the answer is 'no' you cannot hear a difference between amps.
> But in reality most all amps have some coloration of sound whether intentional or not.
> Hearing a difference between amps depends on their coloration characteristics and if you know what to listen for. 2 amps that color sound the same way will sound similar. 2 amps that color sound in different ways will sound different.
> So I think the answer is 'yes' and 'no' here in the real world.


Are you talking intentional colouring, or unintentional though.


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## gdstupak

Moonfly said:


> Are you talking intentional colouring, or unintentional though.


It doesn't matter whether it's intentional or not, if it's colored, then it's colored. The sound through most amps has been altered in some way, either the eq or THD or feedback or etc... Hearing the coloration depends on how much there is and if you know what to listen for. Whether 2 amps sound similar or different depends on the characteristics of the sound coloring.


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## JerryLove

gdstupak said:


> But in reality most all amps have some coloration of sound whether intentional or not.


 Assuming that you are discussing only potentially audible coloration (as surely we don't care about what we cannot hear): Please support this claim. 

What was your criteria for coloration here, and how did you determine that most amps had it (indeed, do you mean "the majority of models", or "the majority of sold units"; and are you looking specifically at currently sold amps, or are you including the last 100 or so years). Are you discussing only home-audio amps, or are we also talking about the amp in my cell-phone? And finally are we discussing "at all listening levels", or only at some; and if the latter, which.

I assert that any properly built amp, sufficiently powerful for the load given, will be indistinguishable to the human ear from any other properly built and sufficiently powerful amp on the same load. Though I think this is true for any sort of amplifier: I am actually making this assertion for home-audio amplifiers of the types most likely to be discussed on this board. 

For example: I assert that you would be unable to identify by blind listening my McIntosh 2125 amp from my Yamaha P5000S amp powering my Paradigm S2's at a "reasonable listening level" (let's say <98db @1m) in the listening room of your choosing.

Do you challenge that assertion? Or are you asserting that the majority of amps are either improperly built or not sufficient to the loads they power?


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## Moonfly

gdstupak said:


> It doesn't matter whether it's intentional or not, if it's colored, then it's colored. The sound through most amps has been altered in some way, either the eq or THD or feedback or etc... Hearing the coloration depends on how much there is and if you know what to listen for. Whether 2 amps sound similar or different depends on the characteristics of the sound coloring.


My question really was, are you including DSP modes etc in this, or are we talking about pure amplification in its most straight forward form? Ruling out intentional colouring, which I regard as the afore mentioned, and I'm not convinced you can hear a difference till you push the amps beyond their comfort range, in which case I would argue you need a different amp, but otherwise not.


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## gdstupak

Maybe my earlier post was a little vague and needs elaborating.
I believe when used properly, any properly built amp should not show their coloration (just the amp, no DSP) and should not be distinguishable from another amp that is similar.
In the real world most people (in my experience) push their systems to the limit and then amps will show their true colors.
There's more to my thoughts but I'm trying to watch Poltergeist now.


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## gdstupak

Moonfly said:


> My question really was, are you including DSP modes etc in this, or are we talking about pure amplification in its most straight forward form?


Now that makes sense to me. 
Sometimes you gotta spell things out for me, I'm numb as a Hake.
No DSP, I was sticking to the intention of the thread with just the amp.


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## lsiberian

JerryLove said:


> For example: I assert that you would be unable to identify by blind listening my McIntosh 2125 amp from my Yamaha P5000S amp powering my Paradigm S2's at a "reasonable listening level" (let's say <98db @1m) in the listening room of your choosing.


I'd love to be there for that listening test. Those are some great amps. 

I think a real difference comes with sub amps.


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## Moonfly

gdstupak said:


> Maybe my earlier post was a little vague and needs elaborating.
> I believe when used properly, any properly built amp should not show their coloration (just the amp, no DSP) and should not be distinguishable from another amp that is similar.
> In the real world most people (in my experience) push their systems to the limit and then amps will show their true colors.
> There's more to my thoughts but I'm trying to watch Poltergeist now.


I think people that are more into AV dont push their systems to the limit. I think the people pushing their kit to the limit arent really that bothered and dont really pick up on the rubbish being produced. I think most of us here probably also have system that play to levels we are happy with while still within their happy operating range.



lsiberian said:


> I'd love to be there for that listening test. Those are some great amps.
> 
> I think a real difference comes with sub amps.


You know, Ive compare the EP4000 against the ED 1300 and I couldnt tell any difference. Ive also hear a true IB using an EP 4000 and the IB was the best by a considerable margin. The sub made a huge difference, to my ears, the amplification didnt. I think that the money you might spend on a better amp, once you get to a certain level, is better spent on drivers etc, as the improvements are much more noticeable, and beneficial. This again assumes amps working happily within their limits. Ive heard a single driver sealed AV15 sub of the back of a Bash500, and we swapped it out for an EP2500, and the improvements were significant. The Bash500 was simply out of its comfort zone and it showed, nothing to do with it being a bad amp, it was just simply being asked to much of.


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## gdstupak

Moonfly said:


> I think people that are more into AV dont push their systems to the limit. I think the people pushing their kit to the limit arent really that bothered and dont really pick up on the rubbish being produced. I think most of us here probably also have system that play to levels we are happy with while still within their happy operating range.


I agree and wanted to say the same thing but Poltergeist was distracting me.


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## Ricci

IMHO with modern solid state amplifiers that are not intentionally designed to have some coloration, used within their operational boundaries (below clipping, with some dynamic headroom left and with a load that is representative of that intended for use with that particular amplifier design.), you cannot reliably tell the difference between 2 amps in a double blind scenario. There are subtle differences there but I believe that they are too small to detect reliably and get completely swamped by the distortions and inaccuracies imposed by the room and speaker system. The differences do start to become large enough to be apparent as the amplifiers start to get driven towards the edge of their capabilities. 

Tube amps are a whole other affair and add a considerable amount of coloration which is easily heard.


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## ddgtr

My friend and I did some comparative listening when I bought my amp. Everything was the same except the amps. We auditioned some pure class A vs AB from the same manufacturer only. 3 different amps (2 of them class A monoblocks and the other a stereo AB) and we could tell 99 percent of the time the difference, with the levels all matched. The surprise was that the biggest difference was between the two pure class A amps, which had different output ratings, one at 100 and the other at 160 watts!! 

Up until that point both my friend and I were in the "I don't think the differences are easily audible" camp. I don't claim to be an expert or anything, I just enjoy music and quality gear. Haven't done other comparisons, but on this one the differences were audible and rather obvious: warmth, detail and so on.


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## Joe in Seattle

re: ddgtr, Danny, above

I'd be very interested to know if the 160 class A amp was the one preferred vis-a-vis the 100 watter. That has been my experience in the past with two Yamaha amps.


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## bambino

In short i'm going to say yes there is a differance in sound.:T


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## ddgtr

Joe in Seattle said:


> re: ddgtr, Danny, above
> 
> I'd be very interested to know if the 160 class A amp was the one preferred vis-a-vis the 100 watter. That has been my experience in the past with two Yamaha amps.


Yes, in my case this is correct, the 160 was my favorite. My friend preferred the 100. It just goes to show that personal taste beats everything else!! 

The amps we auditioned are Pass Labs. Overall, I liked the 160 watt monos because of the perfect blend of detail and warmth.

The 100 watt monos were my friend's favorites by far.

I ended up getting the x350.5 stereo, which also puts out the first 30watts in class A. The reason was that it sounded very, very close to the xa160.5 monos while the cost was half. 

Even though both the 100 and 160's shared similar technology, the 160's sounded closer to the stereo class AB than to the 100's.

But again, I was surprised at the differences and at the fact that we could identify them. I honestly expected them to sound similar at low - moderate volume and only separate when played really loud.

Regards


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## Gregr

Hi All,

This is a great question..., one that is asked again and again and always peaks the interest of many people regardless of experience. I find all of the answers useful and interesting.

Very quickly, my background is essentially a lifetime amateur of sorts although I have been paid for electrical work many times past. 

My Dad had a local Tv and stereo sales and service for 25 ++ years. I used to help Id problems and change out modules 60's after HS classes. I used to sing and play harmonica in 60's garage bands. Sound quality was always the question, "Dyna-kit's rule"! My claim to fame..., building an external FM antenna using an old tv antenna and cutting the elements exactly to BCN (Boston) radio frequency I then mounted on a wooden broom stick handle on the New England Farm house 3rd story roof peak in Waterville Maine. 

OK enough. In response to your 1khz premise I will say this. My neighbor during HS was a drummer in several of the bands I did some singing with. I will never forget the day he taught me to "tune his drums".
Striking the drum head near the edge near each tightening nut elicits a tone and not only does the tone need to match at each nut but the overall drum tone is set to a specific tone (frequency). So in this case you can clearly see a 1khz drum tone is much different then a 1khz electric guitar tone. This brings me to a simple principal I keep in the back of my mind these days whenever buying new equipment or setting to listen to reproduced Audio which is music and movies, lectures etc..

I have many thoughts today on "Sound Reproduction". But again very quickly, this one thought supported by my drummer friends drum tuning is simply that "A huge consideration when I buy equipment is the "Material Used" in the equipment and the signal path. Which is why I agree with the original writer the speaker is the least expensive (relatively speaking) place to invest in building a quality system that returns the biggest bang for the buck. 

You will never appreciate the incredible music of a "Boutique Designed System" on a "stamped basket $6 speaker (driver) in a cardboard box". But a well made driver with musical characteristics will certainly make some of the of the shelf low budget receivers old equipment sound very good. But now looking at this flip-side this musical speaker/driver will allow you now appreciate better electronics. Which leads to another question and another point for consideration. The 1khz signal from a guitar and reproduced thru electronic equipment can sound different if attention to combining equipment that create a synergy when used together first and the compromises are not addressed second. 

I heard somebody say/write somewhere once that the more money spent on equipment shares an inverse relationship with the amount of compromise expected in an audio system (unfortunately not always true but a good rule to consider I believe)

Thanks for reading I am anxious for a response..., I gotta go.......:heehee:

Greg


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## Ricci

Isn't there STILL $10,000 waiting for someone who can come in and accurately and reliably do this under controlled double blind listening sessions? I believe that challenge has been going for some 10 years now and no one has claimed the money yet. :whistling: 

Placebo effects and uncontrolled, unmatched variables are powerful things.


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## Sonnie

I do wonder myself if it still stands... and if it does, why no one has accepted it. VERY good question!


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## JerryLove

Sonnie said:


> I do wonder myself if it still stands... and if it does, why no one has accepted it. VERY good question!


 Because no one can actually tell amps apart when the prerequisites are met. 

The challenge you were looking for: http://www.tom-morrow-land.com/tests/ampchall/rcrules.htm


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## Sonnie

Thanks for the link... I like this part:

_Twelve correct responses in a row is certainly a lot of correct listening but $10,000 is also a lot of money for a few hours of easy listening. The way people describe the differences is that they are like night and day. I would certainly not have any trouble choosing between an apple and an orange 12 times in a row. When compared fairly I believe the differences in amps are much too small to audibly detect and certainly too small to pay large sums of extra money for. If I am wrong someone should be able to carefully take this test and win my money. _


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## goyop

I am not sure who moderates this site but I am asking PLEASE next time one of these long threads gets going to quickly insert the link to the $10,000 test challenge. Just when you think that logic and reason has prevailed someone posts another "such and such amp sounds warmer..."

There are real world physical limitations at play in electronics of all types. The power amp test challenge shows that any decent power amp is designed to faithfully reproduce whatever is input to it to the point that it is not possible to tell the difference between power amps. This also applies to power cords and possibly other components. So let's set this aside and help people understand it so they can invest in things that are actually going to improve their system.

In my experience the single biggest variable is the speaker system. It is costly to manufacture tweeters that will accurately produce high frequencies at volume. It is also costly to manufacture woofers that are accurate, can be played at high volume, dissipate heat, not distort when hot, and be long lasting. Speaker enclosures and boxes are no longer any big deal since a computer can crunch the numbers. The drivers are the key.

All said and done, assuming a decent amp and speakers, if you don't EQ your room it makes no difference anyway. 

So let's try to educate the people at this forum of what is possible and what is not. We can agree to disagree and all that business but fact is fact. If no one has taken up the $10,000 challenge and won then let's put our energy and instruction toward actual real world issues that can make a difference. And as far as the psychological tricks our minds play on us, it is OK to tell people that they are being tricked. If you don't want to know the truth then don't come to forums where smart people can explain away dazzling sales strategies.


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## Moonfly

Perhaps we should have added a poll?


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## Sonnie

Good idea... I will go back and add one and notify all who have posted in the thread. :T


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## Sonnie

A poll has been added... please vote.


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## Moonfly

I voted. It shouldnt be to hard to guess which way I went at this point


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## gsmollin

Sonnie said:


> Thanks for the link... I like this part:
> 
> _Twelve correct responses in a row is certainly a lot of correct listening but $10,000 is also a lot of money for a few hours of easy listening. The way people describe the differences is that they are like night and day. I would certainly not have any trouble choosing between an apple and an orange 12 times in a row. When compared fairly I believe the differences in amps are much too small to audibly detect and certainly too small to pay large sums of extra money for. If I am wrong someone should be able to carefully take this test and win my money. _


I offered to take the test, and he wouldn't accept MY conditions- that we turn up the volume until the amps were in overload. I have long maintained that the differences in the amplifiers that people can really hear are caused by overload responses between the amplifiers and the connected speakers. Now this gets complicated quickly, because the testing depends entirely on the amplifier, speaker, and source material in question. The right combination can be heard; other combinations cannot. The challenge is much more stringent, the host chooses the operating conditions, and they don't include overloading any amplifiers.

I won't be voting, because the poll is asking the wrong question.


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## Moonfly

gsmollin said:


> I offered to take the test, and he wouldn't accept MY conditions- that we turn up the volume until the amps were in overload. I have long maintained that the differences in the amplifiers that people can really hear are caused by overload responses between the amplifiers and the connected speakers. Now this gets complicated quickly, because the testing depends entirely on the amplifier, speaker, and source material in question. The right combination can be heard; other combinations cannot. The challenge is much more stringent, the host chooses the operating conditions, and they don't include overloading any amplifiers.
> 
> I won't be voting, because the poll is asking the wrong question.


I would argue that pushing amps into overload is cheating. Its like asking which car is best, the one with the blown engine, or the other one also with a blown engine. Overloading an amp is not within its intended design application. The general consensus is that you cant tell the different between 2 normally operating amps. I would perhaps suggest your indication that its difficult even between stressed amps, supports such conclusions rather than proves otherwise.

You dont have to vote, but I believe the question is perfect. If you dont keep the question simple, then there will be contest to the answer to infinity. A simple question requiring a simple answer IMO best serves the purpose. If you cant answer, its my view you dont have a definitive conclusion on the matter.


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## Sonnie

It is asking the question we want to ask... no reason to get any more technical... most will understand it. The first post also clarifies the question further. :T

From the descriptions I have read of how people describe the differences they hear, it is not from overloading the amps and many are quick to explain they hear the differences at moderate levels. I don't think there are many who will disagree that there can be differences when clipping occurs or when seriously demanding speakers are driving beyond an amps limits... that is not in question here.


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## goyop

> gsmollin wrote: View Post
> I offered to take the test, and he wouldn't accept MY conditions- that we turn up the volume until the amps were in overload.


Most people who offer a challenge are doing so to prove a particular point. Take the challenge or don't. You are allowed to offer your own challenge if you would like to do so.

Product testing has to be scientifically sound and reasonable. Most auto testing is done under normal driving conditions and some evasive or emergency maneuvers are included. You don't often see an auto test that says "let's over rev the engine and see which one throws a rod first." It is a pointless test since no one buys a vehicle with that issue as part of their buying criteria.


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## eugovector

goyop said:


> You don't often see an auto test that says "let's over rev the engine and see which one throws a rod first." It is a pointless test since no one buys a vehicle with that issue as part of their buying criteria.


I'd like to introduce you to every 16-year old in my neighborhood.:bigsmile:


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## gsmollin

The automotive analogies are stretched, but what you are proposing is that we race, say, a Ferrari Italia 458 and a Porsche 911S, but limit the top speed to 150 mph. Which one is the faster car? 

I contend that overload performance is what separates the good power amps from the bad, and most people have no idea what levels they are listening to. Witness the repeated, controlled tests, where every amp is kept in its linear range, that is to say derate the Porshe by 3 dB, from its top speed of 209 MPH to 150 MPH, and we find out that every amp sounds the same, i.e. the Ferrari can do 150 MPH too. These are not real world conditions. Power amps get driven into overload every day in normal use. The way they respond to this colors the sound, and that's what people are hearing.


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## gsmollin

goyop said:


> ...You don't often see an auto test that says "let's over rev the engine and see which one throws a rod first."...


Check out auto racing. Every drive-train gets pushed to the limit. Many don't finish. 

You won't see Consumer Reports do this on your typical mini-van test. Nobody cares, and nobody cares about the ultimate capabilities of a table radio either. If that's your point, then OK, we're not talking about the same thing.

In a home theater, the sound track is supposed to be able to hit 113 dB SPL. You do the math on a typical speaker than has sensitivity of 87 dB at one watt, and you will see that a 90 W/channel amplifier will be in its overload region long before 113 dB gets reached. Besides the obvious fact the speakers are the real issue in how well a HT will perform, the power amplifiers "grace under stress" is what separates good amps from great ones.


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## JerryLove

gsmollin said:


> The automotive analogies are stretched, but what you are proposing is that we race, say, a Ferrari Italia 458 and a Porsche 911S, but limit the top speed to 150 mph. Which one is the faster car?


 Very true, but are we asking "which amp is 'better'" or are we asking "which amp better reproduces music X"? They are very different questions.

Even then: our question is more narrow than that. In a car we might discuss fuel efficiency, as in an amp we might discuss efficiency. A car might have comfort where an amp has attractiveness. Both have interfaces. Where a car has acceleration and top speed, an amp has THD and max power.

But the question is about the ability to deliver music... so which one can better transport a briefcase down the highway at 70MPH? A Ferrari Italia 458 or a Porshe 911S? 

They are the same when it comes to how long it takes the package to arrive. 



> I contend that overload performance is what separates the good power amps from the bad, and most people have no idea what levels they are listening to. Witness the repeated, controlled tests, where every amp is kept in its linear range, that is to say derate the Porshe by 3 dB, from its top speed of 209 MPH to 150 MPH, and we find out that every amp sounds the same, i.e. the Ferrari can do 150 MPH too. These are not real world conditions. Power amps get driven into overload every day in normal use. The way they respond to this colors the sound, and that's what people are hearing.


 It may happen every day... and there may be people that "normally" drive amps into overload.

I don't. No one I'm familiar with from audio circles does in "normal use". The audio shops I've been to do not (at least not on their SS units). I've got at home and used at shops amps with level meters, and amps with clipping indicators. 

*All* amps color sound at overload. So which option is better? Getting an amp that colors it less, or getting one you don't overload?!?


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## Sonnie

I think most people are very sensible when it comes to amps and their limits and I do not see the evidence to support people driving their amps into overload "every day in normal use". You have a few folks who will crank their system up close to or perhaps even exceeding its limits on occasion to maybe show off their system... but in every day normal use... amps are not driven near their limits. The typical home theater enthusiast is much different than your typical car audio teen driving his car around town trying to blow the windows out of his car. Sure people will test their systems on occasion, but normal use is not consistently overloading their amps on an everyday basis... it just ain't happening.


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## Gregr

I don't believe the question is speed at all..., its the ride. Just as can you tell the diff between An Audio Note Monoblock pair and a Sound Design receiver. All wiring and other conditions being equal. The question is not can you tell the diff when they blow up the Q. is "can you tell the diff when each is set up to show what it can do".


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## Gregr

However, if you would like to create your own challenge. If you offer $10,000 to see which amp handles overload best..., I will..., let me be the first to say "my amp will beat your amp" I am ready willing and able.

Gregr:boxer:


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## Sonnie

Hey... that sounds like a challenge right there... :T


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## Gregr

Alright, you have everybody dancing a pretty good jig. I think I get your point. I have a few extreme questions myself. 

Why do we do the amp test on your turf Sonnie. I might accept your challenge if you brought your amp anywhere else though I would prefer it if you were to set up here in my home but you cannot touch my equipment or treat the room in any way. Just set up your equipment next to mine. Then the A/B switch is handled by anybody that has no idea which is which and the person who sets up the the equipment cannot see which switch is open or closed. A true double blind study without placebo control. Although it might make things interesting..., no that would only increase your odds and decrease mine. a third amp is literally "out of the question". The original research question is "can I tell the difference between my amp and yours with all being equal.


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## Sonnie

If I were the one offering the challenge, I would have to offer it on the same terms as Richard Clark and request it be brought to me... after all... I am the one paying out the $10,000. That is part of the challenge. 

Actually it appears some of his challenge is more like a bet... and I would not gamble for a penny, so his challenge is not appealing to me. Would it prove a point? Sounds like it would. I would however, want a non-bias third party to set up the testing conditions.


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## Gregr

One more question..., since we are all in such a testy mood. Did I meet, exceed or did I fail your your real research question. Hope I didn't fail too badly in providing entertainment at least for smollion(i can't read the small type excuse the spelling please). 

Some of the answers are interesting. I have to say I believe I have learned a little about most of the contributors to this thread "can we hear a difference between amps". This is a good question and I do not believe the discussion is complete. Because I do believe Sonnie can set up the experiment so that nobody could possibly hear a difference. I believe in my environment I will pick out the peculiar resonant frequency of my amp in my environment. That would be different in any other environment and I am sure I will not know the difference if there were no resonant frequency. Unless maybe if we use my wires: power cables interconnect, speaker cable, fuses..., not part of the original research question. 
I am not going to challenge anybody. I have too many questions.

Room Tx 
crossovers
All the best of course but inexpensive Ha! Ha!? 

Gregr


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## lcaillo

Where did Sonnie ever suggest that he was trying to set up an experiment at all, much less set it up so that such a result was achieved? There are differing perspectives here. No surprise in that. I agree that there is more to the question, but no one will be allowed to be testy here and no one is attempting to judge your success nor failure at any task. The topic was raised to engage discussion on a matter that has very different perspectives. Just because people have strong opinions does not mean that we cannot discuss it in a civil manner nor that anyone is going to be set up for a particular result.


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## Gregr

My mistake I assume too much, excuse me, please. However, I am enjoying watching all of you. I had hoped I wasn't alone. But you know what I am not having fun anymore. 
Good By


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## gdstupak

Gregr said:


> Because I do believe Sonnie can set up the experiment so that nobody could possibly hear a difference. I believe in my environment I will pick out the peculiar resonant frequency of my amp in my environment. That would be different in any other environment and I am sure I will not know the difference if there were no resonant frequency. Unless maybe if we use my wires: power cables interconnect, speaker cable, fuses..., not part of the original research question.


So you're saying that you might be able to tell the difference between your amp and Sonnie's amp because your amp has a fault that causes a 'resonant frequency.'


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## Moonfly

The test would need to be done in an Anechoic chamber if we are really talking about doing the test properly. That said, any room influence should be the same across all amps, and shouldnt be a factor, but removing it as a possibility would be the ideal.


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## gsmollin

I think this thread is moving along pretty well. Over at the "Science" forum, the discussion would have fragmented into personal attacks long ago. We're a level-headed group over here, and stick to the issues while staying civil. And in the vein of sticking to the issues...

No more car analogies. As I said, they are stretched. 

I haven't used the word "clip" in this discussion, but rather "overload". There is a distinction. "Clipping" is a particular overload that occurs when the output transistors enter the saturation region (base forward biased, collector forward biased), which happens quickly, within a volt or two, at the peak of the waveform. In the saturation region, collector current will not be controlled by base current. In the linear region of operation, with the base forward biased and the collector reverse-biased, the collector current will (largely) follow changes in the base current.

My definition of overload is more general, with clipping being a special case. In real world operation, the load is rather dynamic, and especially the speaker's crossover can provide pathological loads. More than one 3-way crossover presents a series-resonance to the amplifier at the crossover frequency that can cause the impedance of an 8-Ohm speaker to dive to <3 Ohms, i. e. 2.8 ohms in one highly regarded speaker. If the amplifier has the drive reserves to maintain a low distortion output in the face of a 3 Ohm resonant load at (say) 400 Hz, then there will be no coloration of the sound. If it doesn't, then there will be a coloration. The output drive capabilities are dependent on output level, because the amp is inherently very non-linear, and depends on a lot of feedback to correct its response. At high drive levels, and low-value load impedance, an amplifier can run out of drive and begin to distort, well before onset of clipping.

I had one such amplifier, a brand-name AVR with an 8-Ohm rating, and a switch to set it to 6-Ohm. I never liked the sound of this amplifier, but didn't know why, until one day it actually tripped-off on a sound transient in a movie. I could re-create the event over and over. The sound level at this time was not especially high, and not at the amplifiers limit, in terms of clipping. After discovering the <3 Ohm speaker impedance at 400 Hz, I set this amp to 6-Ohm operation. After that, it wouldn't trip off, but I liked the sound even less. So I replaced the amp, and picked out a better specified amplifier with generous 4-Ohm ratings. You can spot that on a spec sheet because the power at 4 Ohm is double the power at 8 Ohms. Since replacing that amp, I now _like_ the sound of my HT, and also use it for music.

Because I lived this event, it has made a lasting impression on me, and forms part of the basis of my opinions of these items. I would agree that two amplifiers, operating well inside their spec envelopes, will sound virtually indistinguishable. However, I will also add that this happy situation happens less often in the real world than we would like, and that is the reason threads like this one are perpetually, heavily subscribed.


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## Sonnie

gsmollin said:


> I had one such amplifier, a brand-name AVR with an 8-Ohm rating, and a switch to set it to 6-Ohm. I never liked the sound of this amplifier, but didn't know why, until one day it actually tripped-off on a sound transient in a movie. I could re-create the event over and over. The sound level at this time was not especially high, and not at the amplifiers limit, in terms of clipping. After discovering the <3 Ohm speaker impedance at 400 Hz, I set this amp to 6-Ohm operation. After that, it wouldn't trip off, but I liked the sound even less. So I replaced the amp, and picked out a better specified amplifier with generous 4-Ohm ratings. You can spot that on a spec sheet because the power at 4 Ohm is double the power at 8 Ohms. Since replacing that amp, I now _like_ the sound of my HT, and also use it for music.


I know my Onkyo receiver has a 6 ohm setting... and I might understand a lower powered receiver that is "over-rated" in power having a difficult time driving low impedance speakers... such as my MartinLogan Prodigy's... and a few others... if played at or near reference levels continuously... especially if it is all five channels driven. I use Emotiva XPA-1's on my Prodigy's and my 906 runs the center and rear. I hopefully plan to upgrade to a UMC-1 and XPA-3 sooner or later.

Take the Onkyo 876 receiver rated at 170 watts minimum continuous power per channel, 6 ohm loads, 2 channels driven at 1 kHz, with a maximum THD of 0.1%. But what is it with all channels driven at 6 ohms... and the receiver is NOT rated at 2 or 4 ohms... in reality it is not designed to power 3 ohm speakers. So in this case you are not comparing apples to apples. You even said you picked up an amp with a generous 4 ohm power rating. Had you been running Klipschhorns, do you think you would have noticed that same difference?

You can probably find an exception with several lower powered receivers vs higher powered amps (or even amps designed to run 2 ohm loads) if you are using speakers that are not really designed to be used with those kinds of lower powered amps. 

Where I think most people are claiming there is no audible difference in is between say an $18,500 Krell 402e at 400/800 watts per channel 8/4 ohms respectively... a $2995 Bryston 4B-SST at 300/500 watts... a $1,350 Parasound 2250 at 250/400 watts and maybe a $709 Emotiva XPA-2 at 300/500 watts.... and maybe we do throw a few receivers in the mix... say a Rotel RSX-1560 A/V Receiver and a NAD T-785. I think you might have a hard time even with difficult to drive speakers determining a difference in these under equal testing conditions.


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## goyop

The car analogy was simply to point out the absurdity of testing amps for listening difference at clipping and get back to the initial question of whether a person can hear the difference between two amps under identical listening environments.

I have been in studio recording and live sound off and on for 25 years. I am an electrical engineer and have been on jobs where all these subtle parameters are tested and documented. In all my experience we have never designed nor used any system anywhere near clipping. That is just poor system design. It is also terrible for speakers. In any given situation we design plenty of headroom into the system so that we never approach clipping. We never come close to clipping and if it were to happen we would back it down and fix it as soon as possible.

Design the system correctly, use it within its design limitations, and enjoy pure clean sound. If you need more power buy more power. Nobody designs amps to be run at clipping and nobody designs systems to clip at top volume.


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## gsmollin

Sonnie said:


> ... and the receiver is NOT rated at 2 or 4 ohms... in reality it is not designed to power 3 ohm speakers. So in this case you are not comparing apples to apples. You even said you picked up an amp with a generous 4 ohm power rating. Had you been running Klipschhorns, do you think you would have noticed that same difference?
> 
> You can probably find an exception with several lower powered receivers vs higher powered amps (or even amps designed to run 2 ohm loads) if you are using speakers that are not really designed to be used with those kinds of lower powered amps.
> 
> Where I think most people are claiming there is no audible difference in is between say an $18,500 Krell 402e at 400/800 watts per channel 8/4 ohms respectively... a $2995 Bryston 4B-SST at 300/500 watts... a $1,350 Parasound 2250 at 250/400 watts and maybe a $709 Emotiva XPA-2 at 300/500 watts.... and maybe we do throw a few receivers in the mix... say a Rotel RSX-1560 A/V Receiver and a NAD T-785. I think you might have a hard time even with difficult to drive speakers determining a difference in these under equal testing conditions.


I have to point out that all my speakers are _rated_ at 8 Ohms. They have been connected to amplifiers _rated_ to drive 8 Ohm speakers. The problems are in what is _not_ in the ratings. The issue with 3-way crossovers has come up in speakers costing hundreds at Best Buy, and speakers costing thousands, and sold only at authorized dealers. I don't know what kind of load the Klipschorn presents to the amp. I do know that you should have plenty of headroom in a small room with these monsters, since you are sitting in the mouth of the bass horn. I expect my old amp would have done well with them, because of all the headroom.

I'm not dropping names about what brands of amplifiers will sound better or worse, that has never been my point, or the amount of money you spent. I hope that spending 6 figures on an amp will give satisfaction, but I'm not so naive that I really expect it. In the experiment quoted above, Zipper couldn't tell the difference between an old Yamaha and some boutique monoblock.


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## gsmollin

goyop said:


> The car analogy was simply to point out the absurdity of testing amps for listening difference at clipping and get back to the initial question of whether a person can hear the difference between two amps under identical listening environments.
> 
> I have been in studio recording and live sound off and on for 25 years. I am an electrical engineer and have been on jobs where all these subtle parameters are tested and documented. In all my experience we have never designed nor used any system anywhere near clipping. That is just poor system design. It is also terrible for speakers. In any given situation we design plenty of headroom into the system so that we never approach clipping. We never come close to clipping and if it were to happen we would back it down and fix it as soon as possible.
> 
> Design the system correctly, use it within its design limitations, and enjoy pure clean sound. If you need more power buy more power. Nobody designs amps to be run at clipping and nobody designs systems to clip at top volume.


Well I'll agree that the car analogy was absurd.

Since we're sharing resumes, I hold an MSEE and had a pro sound career many years ago. After that I went into aerospace and most recently work in the energy industry. In all my experience we never designed or used a system outside its specifications: Clipping, gain compression, third order intercept, and pages of other requirements were analyzed, inspected or tested. That's engineering. 

This forum is about _home_ theater. People buy some equipment, plug it together, and start showing movies. There is no design engineer, no spec, no testing, no nothing, and a lot of equipment that ought to play well together doesn't. So people hear problems. I know I did. They aren't sure what it is, and it may be room acoustics as well as anything else. Amplifiers frequently get blamed, and maybe some a culpable, and probably most aren't. Maybe they are clipping the amp by overdriving it, or maybe it's some other fault. We will never find out. 

What I have contended over and over, and will repeat myself yet one more time, is that when people are hearing a difference between two amplifiers they are hearing some kind of problem with the system. Changing the amp may fix the problem, but there was some departure from normal operation that they heard.


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## Sonnie

gsmollin said:


> I have to point out that all my speakers are _rated_ at 8 Ohms. They have been connected to amplifiers _rated_ to drive 8 Ohm speakers. The problems are in what is _not_ in the ratings. The issue with 3-way crossovers has come up in speakers costing hundreds at Best Buy, and speakers costing thousands, and sold only at authorized dealers. I don't know what kind of load the Klipschorn presents to the amp. I do know that you should have plenty of headroom in a small room with these monsters, since you are sitting in the mouth of the bass horn. I expect my old amp would have done well with them, because of all the headroom.
> 
> I'm not dropping names about what brands of amplifiers will sound better or worse, that has never been my point, or the amount of money you spent. I hope that spending 6 figures on an amp will give satisfaction, but I'm not so naive that I really expect it. In the experiment quoted above, Zipper couldn't tell the difference between an old Yamaha and some boutique monoblock.


Granted... not all speakers are created equal regardless of their ratings. MartinLogan's are typically rated at 4 ohms, but an amp is going to see a 1-2 ohm load from those speakers at certain frequencies.

I know where you are coming from with your previous situation of swapping out a receiver for a more powerful amp and your speakers coming alive, so to speak. I had a Denon 2807 on full MartinLogan setup (Ascent i's for mains) and when we were cranking it on up pretty well on David Gilmour in Concert, we felt like the receiver was running out of gas... and it really did not sound like what I was expecting it to... it certainly did not have that clarity that I was hearing at the lower volumes. It sounded like the instruments were bleeding together... distorting. We contributed it to the receiver (which I believe was tested at about 70-80wpc true power) not being able to handle the demanding ML's at higher volumes. Don't get me wrong... I fell in love with the ML's on that Denon receiver at moderate-medium listening levels... it was astounding, but we were really cranking it on up there on a few occasions. Later I connected an Anthem setup (AVM-50/MCA-50)... did not notice any difference until we cranked it on up really high. We certainly perceived it was cleaner at those higher volumes. Later I place a NAD T-785 in the system... no difference from the Anthem setup whatsoever at any volume. So I firmly believe there are certain speakers that simply will not perform to their full capabilities on a lower end lower powered receiver.


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## Sonnie

gsmollin said:


> In the experiment quoted above, Zipper couldn't tell the difference between an old Yamaha and some boutique monoblock.


It does not say what volume levels they were listening to... and the Duntech Marquis speakers may not have been that difficult to drive. 

I will say that it is not in my plans to buy any expensive amps (such as Pass Labs) for my ML's.


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## Ricci

Moonfly said:


> The test would need to be done in an Anechoic chamber if we are really talking about doing the test properly. That said, any room influence should be the same across all amps, and shouldnt be a factor, but removing it as a possibility would be the ideal.


Actually no it wouldn't at all. You can use almost any system or room you want provided that: #1. It stays exactly the same other than the change of amps. #2 The speakers and level used do not present a load that drives the amplifier into a range of non linear operation. ( No using electrostats at high volume with a cheap receiver guys.:nono #3 The amps are perfectly level matched. #4 The listener attempting to discern the differences cannot see or otherwise know which amp they are listening to at any time. #5 the amps shouldn't be intentionally color'd to begin with. Some amps are (tube amps, older rockford fosgate car amps, etc.)


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## recruit

Ricci said:


> Actually no it wouldn't at all. You can use almost any system or room you want provided that: #1. It stays exactly the same other than the change of amps. #2 The speakers and level used do not present a load that drives the amplifier into a range of non linear operation. ( No using electrostats at high volume with a cheap receiver guys.:nono #3 The amps are perfectly level matched. #4 The listener attempting to discern the differences cannot see or otherwise know which amp they are listening to at any time. #5 the amps shouldn't be intentionally color'd to begin with. Some amps are (tube amps, older rockford fosgate car amps, etc.)


The above is more or less a perfect selection for determining if there are any differences between amps


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## Moonfly

Ricci said:


> Actually no it wouldn't at all. You can use almost any system or room you want provided that: #1. It stays exactly the same other than the change of amps. #2 The speakers and level used do not present a load that drives the amplifier into a range of non linear operation. ( No using electrostats at high volume with a cheap receiver guys.:nono #3 The amps are perfectly level matched. #4 The listener attempting to discern the differences cannot see or otherwise know which amp they are listening to at any time. #5 the amps shouldn't be intentionally color'd to begin with. Some amps are (tube amps, older rockford fosgate car amps, etc.)


Which was kind of what this comment was aimed at:



> That said, any room influence should be the same across all amps, and shouldnt be a factor, but removing it as a possibility would be the ideal.


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## lcaillo

One thing to consider is that if there are multiple listeners, which will depend on the testing scenario, there may be bias in the listening position that might make some aspects of any potential differences more or less obvious, or provide distractors that might bias the result themselves. Distractors are variables that may not have any direct effect on what is being tested, but may affect the sensitivity of the test to detect differences or create a focus on some irrelevant detail that affects the attention of the listener.

For instance, suppose that there is a room effect that creates a null or boost at a certain frequency that annoys or simply catches the attention of a particular listener. After listening a bit, the listener might accomodate that difference and not notice it and be able to attend to the rest of the spectrum better. The result might be a conclusion that some difference exists that might not. Of course, multiple trials, random presentation, multiple levels, and other experimental techniques might be applied to minimize the effect of such problems. That takes careful experimental design, however, which may or may not be present.

The point is, room acoustics CAN be accounted for in experimental design but anytime you deal with such a variable that can introduce a bias or variablility you have to consider the implications for the design in terms of numbers of trials, randomizing conditions across subjects and trials, and the effect of the variablility on the ability to detect differences.


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## Moonfly

The anechoic chamber would be the best way forward, not because it would remove the room effects, but because it would remove the tendency to blame such possibilities for the end result, as in failing the test etc. While such a test would be possible in any room, removing any human elements (such as looking for blame in failure situations) would be the ideal IMO.

Thats really what I was trying to get at.


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## JerryLove

lcaillo said:


> One thing to consider is that if there are multiple listeners, which will depend on the testing scenario, there may be bias in the listening position that might make some aspects of any potential differences more or less obvious, or provide distractors that might bias the result themselves. Distractors are variables that may not have any direct effect on what is being tested, but may affect the sensitivity of the test to detect differences or create a focus on some irrelevant detail that affects the attention of the listener.


 Doesn't matter. All of those factors are independent of the amp. If the amps sound the same then all of those factors will play out identically. 

The one exception would be in an abnormally bad location and assuming that there *was* a difference. I don't think I could tell an overloading amp from a non-overloading amp if I'm standing next to a jet engine at the time. 



> The point is, room acoustics CAN be accounted for in experimental design but anytime you deal with such a variable that can introduce a bias or variablility you have to consider the implications for the design in terms of numbers of trials, randomizing conditions across subjects and trials, and the effect of the variablility on the ability to detect differences.


 Multiple, blind, and random are certainly required. There can be no doubt.



Moonfly said:


> The anechoic chamber would be the best way forward, not because it would remove the room effects, but because it would remove the tendency to blame such possibilities for the end result, as in failing the test etc. While such a test would be possible in any room, removing any human elements (such as looking for blame in failure situations) would be the ideal IMO.


 I think they would just blame the anechoic chamber and argue that the amps make a difference that, when interacting with their room, is a huge deal.

The ideal scenario is to test in an area that the person claiming "I can hear the difference" has claimed to hear the difference.


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## lcaillo

IMO, the ideal situation is good experimental design that eliminates as many variables as possible and controls for the rest. What either side argues as bias is not as relevant as using methodology and analysis that is good science and can be used to further knowlege regarding what is audible and under what conditions.

I agree that if one is trying to determine whether claims of being able to detect differences are accurate and one is trying to disprove those claims it make sense to use the conditions that satisfy the claimant. This, however, is not good science. Good science does not try to disprove the beliefs of some in favor of those of others. Good science extends knowledge in an area through experimental manipulation of variables and appropriate analysis of results. No good experimental design sets out to prove that there are no differences. One makes a hypothesis and fails to reject the null if there are no differences.


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## JerryLove

lcaillo said:


> I agree that if one is trying to determine whether claims of being able to detect differences are accurate and one is trying to disprove those claims it make sense to use the conditions that satisfy the claimant. This, however, is not good science. Good science does not try to disprove the beliefs of some in favor of those of others. Good science extends knowledge in an area through experimental manipulation of variables and appropriate analysis of results. No good experimental design sets out to prove that there are no differences. One makes a hypothesis and fails to reject the null if there are no differences.


 So if one wants to determine how a wolf pack hunts: it would be bad science to observe a wolf pack hunting in the woods (as this would lack a manipulation of variables) and instead would stick individual wolves in empty rooms with (preferably artificial: as they are more consistent) prey ?!?

By removing the conditions under which people claim to hear differences, you may remove the actual cause of those differences. What if the amp causes the speakers to excite walls differently than another amp?

No. If you want to know if amps are different all you need is a meter.
If you want to know if differences are audible: you use headphones.

If you want to test the claim that people can hear differences: you do it in the setting that it has been claimed in.


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## lcaillo

If you want to do good science you control for as many variables as you can and manipulate the one under test. If you hypothesize an effect due to room acoustics or the interaction with loudspeakers or whatever, you treat that as an experimental variable.

Observation is the start of all science. Some knowledge is gained from observation, some from experimentation. When you are testing a condition such as described here and trying to define the conditions under which differences may exist, it is entirely reasonable, actually expected, to control as many variables other than the one under test as possible. It may be reasonable to use a setting that is similar to that in which subjects who claim to hear a difference are accustomed, but the results may not be as conclusive as many would like to consider if sufficient controls are not in place. I explained above one example of how room acoustics could have an effect that is not controlled for. There are many considerations in any study and generalizing is difficult. One has to consider each on its own merits. The context of a specific experiment needs to be considered, along with the number of trials, source material, subjects, and all of the specific conditions.

If you simply want to determine whether a particular individual can tell the difference between two amps in a given system or not, then what you describe is fine. My point remains that there is much more to be learned from experiments that are more targetted to discovering what is audible and to what degree in more carefully controlled designs.


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## JerryLove

It's still the same problem. You are watching a wolf in captivity and trying to add a tree and bird-call to get wild predation. In theory, theory is the same as practice; but is practice it isn't. 

I assert that you are working backwards. You would first need to determine that a difference in experience exists and then attempt to determine the cause. If you don't all you are going to do is a thousand tests to end up right where I suggested you start and know nothing more than if you had skipped ahead. 

Since you are interested in science (thought I'm not sure why): science is the process of creating models which can be used to make accurate predictions about reality. You want to execute a scientific experiment? Then describe your model and show how you are testing a falsifiable prediction. If you do not, then you are tossing around the term "science" rhetorically.

I'm interested in practical reality. It is less an issue of accurate models and more an issue of proving or disproving a claim of fact. As such: burden of proof falls on the positive claim. The positive claim is that a difference can be detected. 

Better still is the claim that a difference *is* detected under some set of conditions.

Obviously: if a difference can be detected under some conditions, whether it can be detected under all conditions is not really important to establishing the presence of a difference. (obviously: we must remove non-auditory tester bias... all things must be the same except that which is being tested).



> If you simply want to determine whether a particular individual can tell the difference between two amps in a given system or not, then what you describe is fine.


 Isn't that exactly the claim being tested?!? It's the title of the thread.

Now if you found a difference and then wanted to understand *why*. THEN I would agree with your proposed methodology to isolate the cause.


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## lcaillo

More precisely controlled experimental designs are desirable in my opionion. If you think otherwise that is your opinion and you are welcome to it. I don't care to batter the corpse any longer. I have made my point and you have a different view. So be it.


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## Moonfly

JerryLove said:


> I think they would just blame the anechoic chamber and argue that the amps make a difference that, when interacting with their room, is a huge deal.
> 
> The ideal scenario is to test in an area that the person claiming "I can hear the difference" has claimed to hear the difference.


This is a good point, but with one caveat. You then have to decide if the room is the difference, or the amp, or a combination of both. This would require doing the test again and again in multiple rooms to iron out the issue of room interaction, human perception and amp variation. Its well documented how the 5 human senses are basically one sense, with each influential on the other, in scenarios far outside of what is seemingly logical, and that the human mind takes short cuts based on experience to define what it thinks should happen. The individual senses arent fooled, but the mind is, by its own choice.

This leaves one solution IMO. Remove external influencing factors as much as possible, and especially factors that will manipulate the genetically inbred human tendency to assume results. I would do the test in a controlled environment, and go so far as to blindfold the subject etc to remove the influence of or other senses on the test. There does come a point though, were your just going to extremes to try prove a point, and real world scenarios are more representative. Round and round we go.

IMO, the round and round we go result is a clear indication of an area that is being explored to simply try prove a point, when there probably is no need, and no point to really prove, in this case, proving you can hear there difference.


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## Theresa

I tried out a McIntosh first gen solid state amp in the '70s (after my brother repossessed it) and it was truly awful as I believe all first gen transistor amps did. In the '90s I thought a Sony basic stereo amp sounded better than an old Sherwood amp did. These days I don't think that there is a difference in sound between well designed amps with low distortion, certainly those with flat frequency, and low thd and IMd. Measurement of sound equipment has been going on for many decades and today a thorough objective test suite will show what is causing differences in sound. One might like different colorations, I certainly like some, but if the amp tests well it will be neutral.


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## gdstupak

Concerning testing environment.
As long as the amp is the only item changed in the system, it doesn't matter what the environment is. If the sound between amps is different, it has to be the amp itself.
I do believe listening in a controlled environment would make it easier to hear a difference if there is one, because it would minimize outside distractions.
Wolves separated in captivity would act differently than a pack in the wild, but wolves and amps are completely different beasts. The amps have no idea where they are, and do not change their characteristics.


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## Theresa

You are correct. There is all sorts of non-sense that goes on but at the same time there are measurements that explain all sorts of real differences in sound. One of the problems is people often compare the difference in sound between an inexpensive (or even $2000 one) receiver and a separate power amp. Receivers almost always overstate (lie) their power output and distortion will be much higher because of an insufficient power supply. I therefore doubt that there is a sound to amplifiers that can't be explained through measurement. Perhaps there is but that is for someone with more "golden ears" (read golden pockets) than me. If so they should spend some time coming up with a measurement that quantifies this and not use the subjective "language" (without correlating the word with something that can be measured) that has been developed by those selling and reviewing the very high end.


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## Ricci

I've got to agree with Jerry on this one.

*The room is not a variable.* It must stay the same during the tests otherwise it becomes one. Anything that is acting equally on both DUT's is not a variable. That word indicates that there must be some sort of change happening which there would not be otherwise the entire test would be invalidated. On a side note I'd contend that listening to speakers in an anechoic chamber would be a much stranger condition and effect on the listeners perception of sound than any usual acoustics issues present in a much more normal, random, room environment, taking much longer to get acclimated to.

Sure...Ideally you'd want as accurate of a playback system with as wide of a bandwidth as possible and the best environment possible with the lowest noise floor and intimately familiar material to listen to, but all of that doesn't really relate to the real world. 

Let's say that you stick big time music producer Rick Rubin who has spent many years critically listening to music and probably knows how to spot minute differences in the sound, in a huge anechoic chamber outfitted with the most neutral set of passive speakers somoeone like Genelec or JBL can engineer coupled with laboratory grade power supply and front end electronics. You lock him in there for a month listening to his music on both amps with them being switched randomly in between songs so he can get used to the system and chamber. Then you do another 14 days of the tests where he guesses which amplifier is on for each of 72 songs a day. We'll get MIT to run the whole deal. At the end of it compile the results. Lets say that he actually got a statistically significant, higher number of guesses right than just chance would suggest. 

Does that prove that *you* can hear the difference in amplifiers? Should you start listening to them before buying to use in your room at home? Personally I'd say no. Others would say yes we have the proof..EAT IT LOSERS!lddude: Obviously there are real measurable differences between most amplifiers and the way I see it if a test happened like that it would prove conclusively one way or the other whether it is possible to tell the difference reliably with the human senses, but it wouldn't mean much in the real world of inferior: speakers, acoustics, listeners, noise floor, etc. Basically if a scenario like that is what it takes to be able to tell the difference conclusively, a percentage of the time, what chance would there be for Sonnie to do the same in his underground swamp fortress? What if Mr. Rubin with Uber system and MIT moderation failed to identify the amps reliably?


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## Moonfly

OK, here is something for you to mull over. If a 'real world' room is the test room, and a participant does detect a difference, then in theory, changing the room to one with different effects should still yield the same result should it not. It might even be conceivable to say that the fairest test would be one that is replicated in a few different rooms. If the results vary, the room is to blame, and an anechoic chamber would then be the only logical test facility. Swapping the order of the test questions would further help resolve that issue.

So I ask, why even risk that variable, and not just rule the room out anyway. The fewer variables the better the test, is that not the preference of science.

There are other concerns too, what if you used a pair of 50$ speakers, would that be a fair test . Obviously it wouldnt, but what would such a test reveal about amps? I'm with you on this though Ricci, if that is the kind of test required to prove this, then the results probably show its something we really dont have to worry about, meaning that a no vote above would be technically incorrect, but in the real world, actually closer to the real world result truth.


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## Sonnie

I don't see where the room is going to matter if everything is equal other than the amps being swapped out.


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## atledreier

Something that stays the same is not a variable, it's a constant. And in mathematics, constants are usually pretty easy to get out of an equation. And also in real life.


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## Jungle Jack

I must say that for a Thread that could easily devolve into anarchy and personal attacks that this Thread has gone quite well. Props to all who have taken part.

While I have never heard massive differences in the Amplifiers I have Owned over the years, I do believe in having large Power Transformers and high levels of Capacitance. This is predicated by the Electrostatic Speakers I have been using for over a Decade. Using a 5.1 Electrostatic Surround setup has really made me grateful that I have powerful Amplifiers that are stable down to 2 Ohms. 

Electrostats are simply Speakers that are quite demanding of Amplifiers. Not only do they drop below 1 Ohm in the upper registers, but they present a difficult Capacitive Phase Angle. With Sonnie's Prodigies, while little Musical Information is present where Electrostats present their lowest Ohm load, at around 8 khz where there is plenty of action the Ohm load is still 3.55 Ohms with a Capacitive Phase Angle of -58 degrees. 

While there might not be great sonic differences between the Amplifiers I use, not all Amplifiers are capable of coping with the demands of Electrostatic Speakers. Interestingly, it is the highs that are rolled off when not using a sufficiently powerful Amplifier.
Cheers,
JJ


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## Moonfly

Sonnie said:


> I don't see where the room is going to matter if everything is equal other than the amps being swapped out.


Then there should be no problems repeating the test results in several rooms, just to be sure, should there. If it was my 10k, I would be adding that into the mix as well. If I was taking the test, I would specifically ask for an anechoic chamber to try give myself the best chance of winning.


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## Sonnie

Not at all... but it would serve no purpose and it is not part of the challenge, therefore it is irrelevant. It is not your 10K anyway... it is his. He gets to set the rules, which are the conditions of the challenge. If you can really hear a difference, it won't make a difference where you hear it at if all other conditions are equal for the amps in question. If you can hear a difference in room A, then you will hear a difference in room B... or an anechoic chamber... it won't matter... PROVIDED all is equal other than the amps. I am not sure how you would ever rationalize that the listening environment (with everything being equal other than the amps) would cause one amp to sound different than another. Oh wait... there's magic in the air! onder:


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## Moonfly

Sonnie said:


> Not at all... but it would serve no purpose and it is not part of the challenge, therefore it is irrelevant. It is not your 10K anyway... it is his. He gets to set the rules, which are the conditions of the challenge. If you can really hear a difference, it won't make a difference where you hear it at if all other conditions are equal for the amps in question. If you can hear a difference in room A, then you will hear a difference in room B... or an anechoic chamber... it won't matter... PROVIDED all is equal other than the amps. I am not sure how you would ever rationalize that the listening environment (with everything being equal other than the amps) would cause one amp to sound different than another. Oh wait... there's magic in the air! onder:


You werent reading my earlier posts pertaining to human perception and the way the human brain works were you .

Watch this smarty pants, and it will become a little clearer as to the point I am actually trying to make:

http://www.bbc.co.uk/iplayer/episode/b00vhw1d/Horizon_20102011_Is_Seeing_Believing/

Assuming we had one available, I can think of a single reason as to why the tester would refuse an anechoic chamber as the test facility, except of course, unless something was a foot.


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## Sonnie

It is not available in my area... :huh:


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## Moonfly

Figures. Well its basically the science behind the studies of human perception. It details well how the human mind works, and how it combines the information it receives from your senses to result in a best guess result. This happens in everything we do, even when we are aware it happens we cant stop it from happening. Just knowing your in a room thats has factors influencing the result, WILL influence the result like it or not. 

Look up the mcgurk effect and ames room. Both are examples of how your senses fool you, and like it or not all the senses work together in pretty much all scenarios and things like this can and do happen, even when you know about them and are aware they are happening.


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## Sonnie

Regardless... I still believe that if all things are equal and you hear a difference in one room, you will hear it in another. 

If that philosophy did come in to play with rooms and amp testing, the anechoic chamber is going to have an influence on you as well, it's another room. If you can't stop it, you can't stop it, therefore the anechoic chamber ain't gonna stop it. In your scenario, you would not be taking the influences of the room out of the equation... one) because the anechoic chamber is still going to have a different influence on the sound from that of a non-anechoic chamber... and two) because your implication is that it would be impossible to remove the perception from your mind... why would that be any different by going to an anechoic chamber. Silliness! 

Either way, it doesn't matter. If 100 people accept the challenge, I believe 100 people will not be able to determine a difference, regardless of where the challenge is conducted. His method eliminate "chance". The end result is the same.


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## Theresa

I've liked speakers that would probably test badly, such as the Ti Focals and Al Vifas of ten-fifteen years ago. I think its my hearing that was subjected to very loud music concerts in the early '70s. But I have to admit that it is a smooth midrange that attracts me most now. Speaker motors have improved so much. I can hear the difference of 24 bit depth from those that have 16 bit resolution but doubt that I hear any difference between 96kHz and 48kHz. MP3's, especially 128k, sound inferior to me, although I've bought thousands. I wish MP3's were never invented. Dolby Digital (DD, not the HD version) also sounds harsh to me. Even some low-def cd's sound inferior to the best LPs I've heard. I have some 24 bit flacs that I like a lot and I think sound better than a cd. Sometimes technology takes a step backward in order to save on production costs and to appeal to people as the newest "best thing." Solid state was one of those when it was first released, with horrible switching distortion but years later is now neutral sounding (given that better parts are used) and arguably better than tubes (which often color the sound with high 2nd order distortion). I wouldn't mind using a tube amp for the mid-range in a DSP crossed over system, if it had enough power. I am not ready to buy a mid-range receiver as the power supplies are almost universally deficient. What happened to the FTC dictating objective and non-deceptive numbers in ads and specs? I've been to many concerts (folk, classical, jazz (not easy listening or "cool")) and I think my system sounds better better in comparison due to the deficiencies of the sound systems and poor seats/concert hall. Still a live concert is special and highly enjoyable with an energy often not present in recordings. One of my favorite recordings that captured this energy was the LP version of Old & In The Way which sadly was destroyed (mastered by Owsley Stanley, LSD chemist). I also prefer movies on my system because of the deficiencies of sound systems and the 24fps flicker in theaters which for some reason I am highly sensitive to. I have no interest in replicating the sound of a concert hall but rather want something better at home. I do use surround to add a subtle ambiance. Music is a subjective experience but the replication chain does not need to be.


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## Moonfly

Sonnie said:


> Regardless... I still believe that if all things are equal and you hear a difference in one room, you will hear it in another.
> 
> If that philosophy did come in to play with rooms and amp testing, the anechoic chamber is going to have an influence on you as well, it's another room. If you can't stop it, you can't stop it, therefore the anechoic chamber ain't gonna stop it. In your scenario, you would not be taking the influences of the room out of the equation... one) because the anechoic chamber is still going to have a different influence on the sound from that of a non-anechoic chamber... and two) because your implication is that it would be impossible to remove the perception from your mind... why would that be any different by going to an anechoic chamber. Silliness!
> 
> Either way, it doesn't matter. If 100 people accept the challenge, I believe 100 people will not be able to determine a difference, regardless of where the challenge is conducted. His method eliminate "chance". The end result is the same.


I agree I dont think people could hear the difference. My point is simply to eliminate all possible variables as well. An anechoic chamber has the mental effect of most people not knowing what to expect, thus removing preconception and the influence of it, and having that chamber in complete darkness would also aid this experiment as your ears are more sensitive an accurate when the visual sense is removed from the brain. It also serves to make the test as sympathetic to the person taking the test as it does the guy with his 10k on the line. Half the problem is not just the room, its the human being as well, and I think good science would agree with me on these points.

I'm still in agreement with Ricci though, that the fact we are even discussing such extremes, or not, lends itself to the idea the differences are simply too small to make a meaningful difference to 99% of people out there.


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## lsiberian

Sonnie said:


> Regardless... I still believe that if all things are equal and you hear a difference in one room, you will hear it in another. why would that be any different by going to an anechoic chamber. Silliness! .


Well good speakers aren't designed for chambers they are designed for resonate rooms that real people live and work in. So I don't see their merit in this procedure. I think chambers have their place, but in real world audio engineering they fall short. Harman has made a determined effort in the past few years to address this by designing speakers with good off and on axis response. 

I think it's interesting to consider the merits of chamber testing and recognize it's limitation. Sound after all isn't experience in a chamber. I suppose it's similar to Barth's statement about preaching. It's a miracle we perceive anything at all. How fascinating is it that I can get a realistic war experience in my own home without risking my neck(well besides the vibrating sub) 

I don't think we've even touched the knowledge of our own perceptions. What we grasp at are the lights in the sky compared to what's waiting to be unlocked.


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## JerryLove

Moonfly said:


> This is a good point, but with one caveat. You then have to decide if the room is the difference, or the amp, or a combination of both.


 Nope. If the amp can be reliably picked out, then the amp is doing something different. 

It is not logically possible to be able to tell two identical things apart without making them not-identical.

If you can reliably identify one amp from another, then they are different.



> OK, here is something for you to mull over. If a 'real world' room is the test room, and a participant does detect a difference, then in theory, changing the room to one with different effects should still yield the same result should it not.


 No, that conclusion does not follow that presumption. The difference may not be audible under all conditions. 

If I can hear a pin drop in a quiet room, shouldn't I be able to hear it drop with a jet engine near by?
If I can hear a pin drop on tile, shouldn't I hear it drop on carpet?

Let's imagine, for the sake of argument, that the different between amp A and amp B occurs at 19Khz, and that our listener cannot hear 19KHz. Let's then assume that the room our listener is in has a wall that excites at 19KHz and creates a sub-harmonic at 9.5KHz (which our tester can hear).

Yes, the two amps are performing differently (at 19KHz). Yes, the listener can hear it (in that room). No, the listener will not hear it in an anechoic chamber.

Mind you, I type this firm in the belief that two properly built amps driving within limits will not sound different under any conditions.


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## zero the hero

i have no trouble believing 2 amps of the same class sound the same, i just have trouble believing that holds true once you get into class a/b vs class d, class g, class h, etc...


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## JerryLove

O


zero the hero said:


> i have no trouble believing 2 amps of the same class sound the same, i just have trouble believing that holds true once you get into class a/b vs class d, class g, class h, etc...


why do you find that hard to believe?


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## zero the hero

because the switching is visible on an oscilloscope and claimed audible in high frequencies by too many people for me to dismiss arbitrarily because somebody else says that "all amps sound the same"


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## Lucky7!

zero the hero said:


> because the switching is visible on an oscilloscope and claimed audible in high frequencies by too many people for me to dismiss arbitrarily because somebody else says that "all amps sound the same"


But now you have an easily measurable artefact that _may_ be audible. Just because something is visible on a CRO doesn't make it audible.


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## JerryLove

So how has that played out in practice? When you go to a performance with amplified sound can you tell class D from class H by sound? Can you do it at your local speaker store? Do you feel you could pick out my mac from my tammy if i brought them over?


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## zero the hero

A9X said:


> But now you have an easily measurable artefact that _may_ be audible. Just because something is visible on a CRO doesn't make it audible.


i agree- but I won't dismiss it either...


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## zero the hero

JerryLove said:


> So how has that played out in practice? When you go to a performance with amplified sound can you tell class D from class H by sound? Can you do it at your local speaker store? Do you feel you could pick out my mac from my tammy if i brought them over?


i honestly don't know. I could try it at home with my Onkyo 805 and one of my Face F700s (class H), but that wouldn't prove anything to anyone, would it?


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## Theresa

RBTO said:


> it becomes more a matter of things external to the amplifier (speakers, wiring, etc.) for audible differences to exit, and under test conditions where these are minimized, not too many folks would be able to tell when an amplifier has been switched out with another, unless the second has ratings in the basement compared to the first.
> 
> I've never accepted that a high priced amplifier is worth its value solely in terms of sound quality (there might be other factors to consider such as construction & durability). That is more true these days than ever. For those that can't afford the $100K amplifier, don't pine at what you are missing!!! Take solace in that your $2C (that's $200 for those that don't know the Roman numerals) amplifier, if purchased more recently, can and probably does sound just as good as that high priced one under listening conditions most people enjoy.


Wiring? What sort of wiring? RCA vs. balanced? "Directional" that shows which way it should be oriented? Unless you have very long cable runs there would be no difference between RCA and balanced and any difference can be measured so.... where are the measurements? But then again I don't know what you are referring to. I used to have hum problems with wiring and a totally different kind at the photography school I went to in the early '70s where the stereo's speaker wire was of very small gauge (probably 22 or so) and a very long run and picked up police radio calls. Right now I have a couple of surround speakers connected with about fifteen feet of 12 gauge close-out ($10 for 30ft):rofl2: wire and have no such problems and I don't believe I could hear the difference between my $6 closeout interconnects and $700 cables. I guess people get to the point in buying gear where they have bought the most expensive components and speakers and still feel the need to buy more, even if it makes no sense.
I just saw a post about wood blocks that when placed under components makes them sound "better." There is so much that is sold with false claims made for it that I wonder if PT Barnum was right (I think he said this) "A sucker is born every minute."http://www.hometheatershack.com/forums/images/smilies/rofl2.gif


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## Theresa

As a former nurse and mental health professional I would say that physical (include electro-chemical) differences would tell nothing about the sound of the amps but rather only differences in perception (or how perception is processed). Its not that perceptions are not real but rather they are in a different realm and do not necessarily indicate any non-mental difference.


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## gsmollin

The maple blocks give the sound a leaner and more forward soundstage. If you like a warmer and more intimate experience, I suggest you try the Rosewood blocks. I don't care for the walnut blocks, IMHO they tend to construct the image and I have trouble with depth perception


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## ddgtr

Theresa said:


> Wiring? What sort of wiring? RCA vs. balanced? "Directional" that shows which way it should be oriented? Unless you have very long cable runs there would be no difference between RCA and balanced and any difference can be measured so.... where are the measurements? ......


Theresa, I would not be so quick to put the RCA and balanced in the same category. I've had terrible ground loop problems (with short cable runs, that is!!) and after trying EVERYTHING the only way to get rid of the hum and buzz was to switch to all balanced. Again, we're talking less than 10 feet!


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## recruit

ddgtr said:


> Theresa, I would not be so quick to put the RCA and balanced in the same category. I've had terrible ground loop problems (with short cable runs, that is!!) and after trying EVERYTHING the only way to get rid of the hum and buzz was to switch to all balanced. Again, we're talking less than 10 feet!


Turning to balanced solves the Hum?, I presume completely or is there still some slight noise as I would think there is more likely a problem in the loop that would need addressing as runs of say 1M - 3M RCA is the preferred method.

Can you not run in a new spur for say the power amps to isolate them from the more sensitive parts of your set up?


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## ddgtr

recruit said:


> Turning to balanced solves the Hum?, I presume completely or is there still some slight noise as I would think there is more likely a problem in the loop that would need addressing as runs of say 1M - 3M RCA is the preferred method.
> 
> Can you not run in a new spur for say the power amps to isolate them from the more sensitive parts of your set up?


The noise is gone completely.

I have a complicated setup, a 2 channel main rig where my preamp acts as an HT bypass. The receiver's LR preouts go to my preamp. Lots of components connected together by short cables.

After 2 months of troubleshooting, I finally isolated the 2 problems where the amp (Pass Labs X350.5) and the sub (Velodyne CT-150) did not get along, also the HDMI was introducing some noise. I have dedicated 20 amp circuits, tried with and without power conditioners, you name it... The only thing that took care of it was switching from rca to all balanced and introducing an all balanced active crossover (dbx 223xl) to take over from the sub and to act as a buffer between the amp and the sub. Again, my cables are well under 3M.

It sounds really clean now with no noise whatsoever, and I'm pretty picky about my 2 ch. I used to feel the same as you about short rca - that's why I had it connected that way at first. Luckily someone suggested switching to all balanced on a forum...


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## atledreier

But anyway a hum problem would come far from this issue. A hum is a fault condition, and we're talking about healthy systems within their operating range.


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## gsmollin

This problem is pretty common. AVRs have no ground connections, they use two-wire plugs. Subwoofers often use three-wire plugs, and that can cause a hum problem, because the neutral connection is never at the same potential as the safety ground. Adding a BFD or other pro gear that uses 3-wire power will also cause this. There are several solutions, but balanced output is one good one. rejecting common-mode ground noise is the reason for balanced connections in the first place.


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## rosco968

How many AVR's have balanced inputs? It would be a very few of the $$$$$ variety. There is the big problem.


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## recruit

gsmollin said:


> This problem is pretty common. AVRs have no ground connections, they use two-wire plugs. Sub woofers often use three-wire plugs, and that can cause a hum problem, because the neutral connection is never at the same potential as the safety ground. Adding a BFD or other pro gear that uses 3-wire power will also cause this. There are several solutions, but balanced output is one good one. rejecting common-mode ground noise is the reason for balanced connections in the first place.


I suppose that is good to know but most manufacturers say that RCA for short runs is the better connection and most AVR's do not have balanced connections but only single RCA outputs, so that can be quite a big issue to some?


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## ddgtr

gsmollin said:


> This problem is pretty common. AVRs have no ground connections, they use two-wire plugs. Subwoofers often use three-wire plugs, and that can cause a hum problem, because the neutral connection is never at the same potential as the safety ground. Adding a BFD or other pro gear that uses 3-wire power will also cause this. There are several solutions, but balanced output is one good one. rejecting common-mode ground noise is the reason for balanced connections in the first place.


Well said!

Yes, most affordable AVR's do not come with balanced connections, so plain and simple there is nothing we can do about that... Unfortunately..

Here is a great article I found a while back and I learned that a lot of the custom (but not necessarily expensive) cable makers adhere by it. For those interested, it will provide a wealth of information:

http://www.rane.com/note110.html


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## DanTheMan

Don't know if these have been brought up yet:
http://home.provide.net/~djcarlst/abx_pwr.htm
http://bruce.coppola.name/audio/Amp_Sound.pdf
http://www.matrixhifi.com/ENG_contenedor_ppec.htm

Dan


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## recruit

Some Interesting info there chaps thanks for adding it to the thread :T


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## gsmollin

recruit said:


> I suppose that is good to know but most manufacturers say that RCA for short runs is the better connection and most AVR's do not have balanced connections but only single RCA outputs, so that can be quite a big issue to some?


I don't know what would be better about an RCA, single-ended connection. You only need to have the balanced connection on one end of the cable for it to break a ground loop. If you are planning to add an outboard amp you should look for one with a balanced input, so its available if you ever need it. The BFD comes with a balanced input. Long cable runs work best when both ends are balanced because the cable itself becomes a "component" and generates noise signals by inductive and capacitive coupling to noise sources along its route.


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## recruit

gsmollin said:


> I don't know what would be better about an RCA, single-ended connection. You only need to have the balanced connection on one end of the cable for it to break a ground loop. If you are planning to add an outboard amp you should look for one with a balanced input, so its available if you ever need it. The BFD comes with a balanced input. Long cable runs work best when both ends are balanced because the cable itself becomes a "component" and generates noise signals by inductive and capacitive coupling to noise sources along its route.


Agreed, Long cable runs are more suited to balanced connections as they are less likely to pick up interference than say single ended RCA plugs, but for 3M or less RCA should be fine, I used a BFD for a good few years and always used RCA with microphone adapter plugs for the RCA connection at the BFD end and I once never had any type of humming noise from speakers or sub.


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## Jungle Jack

Rainieong said:


> any good amps can recommend? looking for resonable prices..


Hello,
If you could be a bit more specific about your budget, it would greatly help. Also, whether or not you are open to used amplifiers is an important consideration.
Cheers,
J


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## Oktyabr

Sonnie said:


> Can we really hear a difference between two amps?
> 
> More specifically... between two amps that have been level matched in a controlled listening test. We are not talking about amps that have been modified or are driven beyond their reasonable limits.


In a purely hypothetical sense, on paper, no. Two level matched amplifiers driven within their reasonable limits should amplify the signal the same.

In the real world you have to take into account slew and damping factors, the speakers (load) being used, even the difference between a MOSFET, bipolar and a SET output stage can produce auditory differences. Further, not even two amps of the same identical make and model are necessarily the same. Capacitors are certainly made within a tolerance, not exact, and that goes for all the rest of the components in any relatively complex electronic device. Combine all of the above with the frequencies it's being asked to amplify (no one listens to just 1kHz test tones!) and yes, I believe that differences that can be identified through an ABX are possible. An amplifier's job is simple... amplify an input signal and pass it on to the speakers while changing the signal as little as possible, adding as little coloration/distortion as possible. A perfect amplifier is certainly possible on paper but to the best of my knowledge no one, at any price, has ever made a 100% perfect amplifier. Most come close enough for the human ear to be happy with, but even 99% accuracy is not 100%.

Just my $0.02.


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## Gregr

Hey, What happened? How did we end up here..., one more time? Oktyabr does a nice job of rationalizing the numbers to say, "similar but not the same". Amplification is the same and without modification one will or can be adjusted to sound similar to almost any other amp. 

But one question that has not been asked, "Will the music sound the same from begining to end"? The same nuance, same sustain, same recording Q's, like recorded indoors or outside in an amphitheater. Will I enjoy one more than the other. I mean will I simply want to listen to one more than the other?


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## sub_crazy

In a perfect world all amps would sound the same but we are far from that. As was just mentioned no one has made the perfect amplifier, just some do _less_ harm than others so there _can_ be a difference in what we hear between amps.

I know I have heard differences in amps and but the largest difference is in how loud and dynamic they can play without any audible distortion. This was with amps with similar specs as well.


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## tesseract

I just switched from an minimalist passive pre integrated amp to an AVR. No EQ possible on the integrated nor employed on the AVR. While both sound good, big difference in sound between the two of them. 

The AVR is brand new and most likely needs some break in time. Also the AVR signal path is infinitely more complicated than the minimalist amp.


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## robbo266317

In reply to Re: Can we really hear a difference between amps?

Yes! 

Please feel free to arrange a vist and we can compare amps.


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## Sonnie

Are you up for the $10,000 challenge, double blind listening test? 

Of course you could have better ears than Steve Zipser, Tom Nousaine and the others that were listening in those original tests.


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## Gregr

I'm just going to make a simple observation, I will not respond to anybody looking to argue to win any point. I hope nobody is insulted. I am not attempting to make anybody wrong. I am saying I have a few thoughts not that I know anything in particular. I am willing to take a good honest look at any point made, including, watch and listen to two amps competing to sound equal or different. I hope two people someday do put together this experiment or something similar.

The $10,000 double blind test. Isn't that where a few especially talented techheads get together and take two amps of anybody's choosing and restrict amp setup with inferior wiring or optimize the amps to sound identical.

First requisite being neither amp is allowed to enhance overcome manufacturing short falls, audio obstacles, or bottlenecks in other words each amp must use inferior wiring and
connections. In other words you cannot use better cables that optimize or free the amp to play sound at its best. Because if you have a superior amp you can restrict its ability to play open and natural music by using an inferior cable.

I say that if I replace wiring to my Denon and continue with moderately priced Kimber Kable cables out to the speakers I can make a Denon AVR sound pretty good. If you use all of the same cabling for any cheap amp the sound will improve but will not equal the Denon improvements.

Or I will use the MIT cables I recently put in storage. I did have these in the AVR loop until I tried Kimber' 8VS. Right out of the box these sounded nice and they keep getting better. These are a nice match for Denon.

At this point I will add one more thought. I don't think the experiment says very much if two amps are taken out of the box and connected with wires that are not broken-in with the amp planned for this experiment. Also, all of the cables should be from a list of recommended cables for the specific amps used. 

I do not have $10,000 for the bet. But this is the type of experiment that interests me. That is "How good can a cheap amp sound?"

I know I've steeped on some toes here, but I'm no fool. I do not buy electronics equipment because it looks Kool and not because its the most expensive (obviously) and when I do buy my ego is not so invested that I will not admit a mistake nor continue to use a piece of gear that does not contribute to better sound quality. 

When I buy it is because I read something that made sense and several manufacturers are continuing the dialog in a competition to improve the product or ... . Some new technology I am watching now is "QOL" Audio completion. The more I read about it the more interesting it sounds. The cost on this technology is way to high for my budget. But I digress... .

I am interested in sound quality, I cannot afford to buy without good reason. Later when/if I find a flaw which is inevitable I will adjust to minimize the problem. but I have to remember that I still have room Tx problems that is I need room Tx. What I am trying to say is that if I buy and sound quality is neg impacted I am quick to admit it. The only expectation I have is that the product is exactly as the manufacturer has described and not what I want to believe I heard other people say. I am looking for pure copper wire and connectors. Low resistance and capacitance, inductance is managed and EMI, RFI are minimized..., I'm not sure about anything else except reputation.

"Bottom Line" I'm 61 years old this year and I love music. I listen to recorded music 2,4 sometimes 6 or more hours a day. I want the best sound I can manage to put together. I am always looking for improvements that fit my budget. I would like to buy a single Furutech speaker cable @ $133 per meter and I need 2 meter per speaker but I'm letting the Kimber warm up a little. These cables sound like they are building am inner charge..., then the sound begins to weaken and there is a tin-can/string effect in the upper mids and then it rolls into a couple of minutes of heaven. So I'll wait to see if they open up or become consistent at something. If that happens I might just live with these for awhile and instead buy two boxes of wall Tx. But I'm working/finishing a Telecaster build and I need Nitrocellulose Lacquer before I do anything else. 

Enough rambling. Against my better judgement I am putting this out there..., hope you're all having a great spring.


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## Sonnie

Gregr said:


> The $10,000 double blind test. Isn't that where a few especially talented techheads get together and take two amps of anybody's choosing and restrict amp setup with inferior wiring or optimize the amps to sound identical.


I think it is a bit different than this... but check out the first post story for how they setup that test. It had nothing to do with "trying" to get the amps to sound identical, instead they were trying to hear a difference... and they could not. All they did was level match them, simply because two amps not level matched could indeed have a drastically perceived difference.


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## Gregr

It had nothing to do with "trying" to get the amps to sound identical, instead they were trying to hear a difference... and they could not. 

Well, my first experience with the dialog around "hearing a difference" between any two amps led to many statements. Depending on who you listened to..., I'm the new guy I listened to them all and I found the premise and the discussion kinda fun. But I don't remember anybody jumping at the chance for $10,000. But somebody said one amp is pretty much the same as any other..., speakers are more important. I liked that. At some point somebody challenged me and my Denon to sound different than his amp and he would allow my using the MIT's I had in my system that I thought were working pretty well at the time. 

There is part of me that agrees with the idea that one is very much like the next. But , obviously I believe some amps have better bones and you can achieve a higher level of neutral natural open dynamic well damped/controlled sound while other amps may give you vocals but no drums and cymbals or brass improvements (so to speak).


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## lcaillo

And you have hit on the basic problem. All of the opinions on the matter ARE belief. While I agree, there are many amps that are not designed or built as well as we would like and their sound likely reflects that, as an industry we have failed to capture what an amp or any other component "sounds like" adequately in the testing and specifications that we use.

Add to that the fact that what we experience is much more complex than the actual sound, or the actual transfer function of the amplifier, and it is no wonder we get into endless debates on these issues.

I would like to see more controlled research that identifies the differences that people perceive and drills down with testing to discover why they experience what they do. WE would likely find that there are metrics on performance of the equipment that are far better than traditional measurements AND that the perspective and beliefs of the listener have an even greater effect on what is experienced.


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## Gregr

A very nice take on a technology that is still a young and still improving/changing sound recording and playback technology. My feeling is we don't even have the/a language to describe quantifiable music qualities, recording equipment ideals that reproduces at 100% in playback , recording methods that result in the highest quality playback and the equipment necessary for the highest quality playback of recorded sound. There is no lack of dialogue when talking/writing about digital or analog recordings and playback for profit. That is not a bad thing. 

I think also that there are certain requisites necessary for personal satisfaction and professional consistency and in developing this sound reproduction technology. First of all is an ability to hear all of the different parts of music passages. I do not believe perfect pitch is the only type of hearing that provides an ability appreciate music. I would rather have a relative pitch hearing ability (I do Most of the time). To me being able to follow the music is fun and satisfying. But I do wonder what harmonies sound like with perfect pitch..., is listening to music with perfect ears frustrating? You know a guitar string is always loosening..., to be brief. Then it takes constant questioning of my thoughts and expectations to keep an open mind when listening to my music on my system. I have to remind myself to disconnect from critical listening. Because my system does sound good to me at any time I only need to remember to keep an open mind and simply hear/enjoy the music. When I am listening to music as the critic I am listening for for the absence of certain mechanical and electromechanical indicators. Hearing music through a decent system is like watching a movie. In a good movie there is nothing to remind you you are watching a movie. Nothing in the movie takes out of that experience and more importantly the equipment you've invested in contributes to your increased enjoyment of the movie or music system.

Two additional personal qualities that contribute to listening/hearing quality is honesty and willingness. 



lcaillo said:


> as an industry we have failed to capture what an amp or any other component "sounds like" adequately in the testing and specifications that we use.
> 
> .


Honestly I do not believe we have the words to describe a specific quality of sound and the electronics responsible. Just as you say.


"Add to that the fact that what we experience is much more complex than the actual sound, or the actual transfer function of the amplifier,"

Also a good reason their isn't at least one definitive book on the topic. Not for lack of wanting..., sometimes I wonder if we ask the wrong questions.

http://www.bsgt.com/technology-information/about-qol/qol-the-dna-of-sound/

The above link is to BSG Tech. the comapny responsible for QOL sound completion electronics. For $4K you can listen to the complete musical event. What BSG says essentially is electronics reproduces only parts of the musical event. What QOL does is 
identifies musical information not available to the listeners ears in normal music replay
but QOL elevates this additional info to listening levels. Like a digital picture all of the info is there even when all you see is a black photo. With digital audio tech hearing all of the audio info should be available and interesting. 

Enough said for now.


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## lcaillo

Much of the problem is that for the vast majority of users, both professional and consumer, the quality of most of what we deliver in equipment and produced media is adequate. Digging deeper in uncomfortable for the industry that is highly marketing based on the consumer side, because many of the beliefs that drive the design, marketing, and purchase of products would have to be questioned. As you can see by the direction that these kinds of threads take, people do not take kindly to having their assumptions and beliefs challenged. This is particularly true when suggesting that the knowledge that some possess is based largely upon belief rather than fact. This is true of all sides in these debates.

IMO, Bob Carver had some good ideas, thinking of amplifiers and other devices in terms of transfer functions. His ideas could be taken much farther with the technology that we have today. By using high sampling rates and more advanced statistical and signal processing techniques that were not practical even ten years ago we could ask some much more relevant questions regarding the differences between input and output, and the differences between outputs of various devices with the same input. The relevant questions are not whether there are differences, but what those differences are and what aspects of them are meaningful under which conditions to which users.

Technologies such as the ability to process massive amounts of data on multiple variables, perform extremely high rate sampling, wavelet analysis, and highly complex modelling could be applied very effectively if we really wanted to know the answers to the questions. The problem is that many get offended at the notion that we do not currently know all that we need to know, and many get very uncomfortable with challenges to their perspective or "knowledge."

When the majority is happy with where we are, for one reason or the opposite, it is very difficult to move knowledge forward. We have seen that many times through history. Here, we have people who see the world as round and who believe that the other side sees the world as flat. The problem is that both sides think they are the ones who see it as round.


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## DavidA

First of all, thank you for your zero tolerance policy. Too bad it's even needed. Sigh.

As for hearing differences in amps the answer is most assuredly 'yes.' Tube amps sound different than most solid state. Solid state usually has more solid, refined and defined bass. On the other hand, tube amps tend to soften some of the harshness in the treble regions. The treble sound in tube amps is softer, more relaxed, more realistic. Tube amp have less defined bass, generally, and can sound a tad tubby. I have no experience with the hybrids so I can't comment.

My experience with amps includes Dynaco, Heathkit, Crown, Emotiva, McIntosh, Krell, Yamaha, JVC, Sony, Arcam, Teac, Marantz and others I can't recall. Some are indistinguishable from some others, to be sure. In general, youse gets what's you pays for. That's a pretty good general rule, but it's not always the case.

Over the years I have learned that most people don't know how to listen, really listen. In most cases it is simply not important to them so they tend to be less discerning. In many cases differences can be small and affect only a limited audible frequency range. Some amps I've heard have such a luscious midrange that slight deficiencies don't seem to matter as much.

I could go on and on but I won't. In summary, there *are* distinct sonic differences in many amps, preamps, processors, tuners, and receivers, IMHO. But the point to be made is that if you can't hear the differences then they either don't exist, don't matter, or the listener doesn't have a trained ear. This latter point is no small issue to many audiophiles, naturally.


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## Gregr

Lucky for you you threw your thoughts into the pot late at night. I hope you will hold on through the day tomorrow. Several people may/will challenge your position..., you may even get the $10K challenge. If they get an email notice, you can expect questions. I agree with much of your premise and reasoning. 
When the dust settles maybe we'll get back to this. I need sleep

Oh..., Welcome to HTS. After 5 posts this site opens up to you as far as communication. There are some very knowledgeable people here and many have direct experience as well. Should be fun.


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## gdstupak

DavidA said:


> Tube amps sound different than most solid state... The treble sound in tube amps is softer, more relaxed, *more realistic*.


I would have to say that tube amps in general are less realistic sounding because of the distortion they add. So I would say that the treble in a tube may sound more pleasing, but not more realistic.



DavidA said:


> Some amps I've heard have such a luscious midrange that slight deficiencies don't seem to matter as much.


I wouldn't want an amp that has a luscious midrange, I would want an amp that reproduces the recorded audio the most accurately.
This brings up the difference of listening preference for people. There are people like me that believe a good amp is one that reproduces audio accurately, then there is my dad (and possibly you?) that believes a good amp is one that sounds good.
Neither belief is wrong.


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## mdanderson

I was certainly able to tell a difference when I went from an Outlaw 750 to an Emotiva XPA-5. The Emotiva just simply sounded better and more detailed to me.


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## derrickdj1

I think most amps sound the same when they are working in their comfort zone. At higher volume, increase loads,ect.,this may not be true. So my answer is yes and no, which is not one of the choices. I also agree tube gear can impart it's own sonic quality on source material.


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## lcaillo

As with most questions, as you have stated, the correct answer is usually..."it depends."


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## 3dbinCanada

derrickdj1 said:


> I think most amps sound the same when they are working in their comfort zone. At higher volume, increase loads,ect.,this may not be true. So my answer is yes and no, which is not one of the choices. I also agree tube gear can impart it's own sonic quality on source material.


I concur!!! My thoughts exactly.

IHO, here is what I think is the order of sound being affected from greatest to smallest assumiing amps and music sources are solid state.

Speakers & Room Acoustics 98.0%
Amps/Receivers,DVD/BluRay 1.8%
Cables/Intercconects 0.2%


If a turntable is involved... Speakers and room drop down to 85%, turntable/cartridge 13% and the rest remains unchanged.


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## pharoah

i know julian hirsch who was a reviewer for the magazine stereo review.he claimed speakers made a way larger difference.than any other piece of your gear.


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## derrickdj1

Agree, speaker will make a big difference. Then bi-amp with active xo, and room tx's.


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## Dub King

The only caveat I'd throw in there is _some_ people enjoy the characteristics of highly speaker inefficient designs - large dome tweeters, even a dome midrange... plus small woofers, acoustic suspension designs etc. which necessitate a dedicated amp for maximum performance. Many, if not most speakers are efficient enough that almost any modern AVR's amp will drive them... but the flip side is some highly inefficient designs also sound really good (OK I'm thinking of the Image Concept 200's I used to own, personal bias lols).

Often these 'inefficient' speakers are bookshelf speakers, it's just plain easier to make a large, efficient speaker. The good news is that incredibly powerful amps are no longer incredibly expensive - my recent experience with a Behringer iNuke 6000DSP was a real eye opener, it seems impossible something could be so light, so cheap, blow out nothing but cool air... and yet pump over a kilowatt per channel RMS into 8 ohms. In the end I chose a Crown XTi-2002 because I do think amps sound _a tiny bit_ different from each other and I also think Crown amps sound particularly great. Is it psycho-acoustics? Could I pick them out in a DB test? I don't know for sure. I think I could pass the DB test - hopefully I'll have an opportunity to participate in such a test someday soon.



pharoah said:


> i know julian hirsch who was a reviewer for the magazine stereo review.he claimed speakers made a way larger difference.than any other piece of your gear.


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## tonyvdb

"Garbage in, garbage out" your sound will only be as good as the weakest link its not just about the amp but every piece of gear in the loop.


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## Savjac

Of course you can hear a difference, well maybe not everyone. I have heard amps that sound a good deal alike, My Lux and Max example, and have heard amps that sound unlike another amp (Mac and Hafler) in the rack. I mean how can they not, they have dozens if not hundreds of different components, differing topoligies, different designs and are oft times voiced by the manufacturer. How could we have so many different amps in our homes if they did not. We would only need one or two.

Do all cars handle the same while going 60 mph through the mountains in southern Tennessee. No way, yet they all seem to have a similar purpose when they were made. Can we say that all twins are the same...maybe from a DNA point of view, but not personality wise. Does a Class T amp sound like a Class A amp...not likely.

Yes the arguments can be made that while working in their comfort zone many sound similar, but that was not the question. It was black and white. Can we hear a difference and that has to be answered with an ultimate yes imo. I see I am in the minority and that is cool, those that do not hear a difference should be quite happy with anything on the shelf.


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## Andre

Sure and in some cases its actually worth the cost to upgrade (if you have the money), in other cases probably not, unless of course you are the person that spent 60k on amp, then you couldn't possibly convince them that the 5k amp sounded just as good because then he would be admitting he was an idiot.


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## smurphy522

If you consider the topology or design of an amplifier then yes there will of course be differences and many of them sonic ones. Most notably a solid state to digital switching to tube amplifier comparison is noticeable on the same speaker.

One of the problems is level matching if one were to perform a comparison A/B test. Even 1db of a level deviation may be noticeable and ti would also depend on the load they were driving (speakers).

I agree with may who have stated that speakers will make the most difference in creating a sound. As a past salesman in A/V I alsways tried to guide my cusotmers into picking speakers 1st and explaining to them that more $ should be spent on the speakers then the media player or receiver/amplifier.

Yes emphatically I would say there is a different sound from different amplifiers. Can we hear it? Well it all depends on the individual.


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## JerryLove

Savjac said:


> Do all cars handle the same while going 60 mph through the mountains in southern Tennessee. No way, yet they all seem to have a similar purpose when they were made.


Analogies are will get you so far, but eventually break... like cars.

So when driving around southern TN, can you tell what brand battery your car uses without looking? Do you find that the battery affects handling or sound more?

This is, after all, the source of electricity for all your car does... kinda like an amp.


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## Sonnie

I always just go back to the proof (see the first post) and that is the difference we are referencing for this thread. I think we can always come up with certain circumstances where one amp may outperform another in some way, but in a comparison like the first post, I think we don't have much choice but to come away with what that comparison proved... until someone proves otherwise with an acceptable testing method.


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## Savjac

JerryLove said:


> Analogies are will get you so far, but eventually break... like cars.
> 
> So when driving around southern TN, can you tell what brand battery your car uses without looking? Do you find that the battery affects handling or sound more?
> 
> This is, after all, the source of electricity for all your car does... kinda like an amp.


No but there are other items in the electrical system that will cause sound problems in the car.


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## Savjac

Sonnie said:


> I always just go back to the proof (see the first post) and that is the difference we are referencing for this thread. I think we can always come up with certain circumstances where one amp may outperform another in some way, but in a comparison like the first post, I think we don't have much choice but to come away with what that comparison proved... until someone proves otherwise with an acceptable testing method.


I dunno, to me this seems like a counter argument. If we cannot measure it, it cannot be real. That is a bit like happiness or sadness, hope or doubt, if we cannot measure those things how does one quantify them ? Can we measure how much soundstage an amp will produce ? How deep or wide will the sound be ? And no we are not changing anything else but amps in this thought process. How about dynamics, I understand that the Class D amps have tremendous power for the bottom end of a speaker system as there is so little power wasted in the transfer but the top end is not quite as nice. There are differences all over, to deny them because we cannot measure them...today anyway, is probably not correct.


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## 3dbinCanada

Savjac said:


> I dunno, to me this seems like a counter argument. If we cannot measure it, it cannot be real. That is a bit like happiness or sadness, hope or doubt, if we cannot measure those things how does one quantify them ? Can we measure how much soundstage an amp will produce ? How deep or wide will the sound be ? And no we are not changing anything else but amps in this thought process. How about dynamics, I understand that the Class D amps have tremendous power for the bottom end of a speaker system as there is so little power wasted in the transfer but the top end is not quite as nice. There are differences all over, to deny them because we cannot measure them...today anyway, is probably not correct.


Unless solid state amps are pushed beyond their design limits, the only difference in sound among them is a biased perception based on sight, moneys spent to purchase the upgrade, etc. These biases make us hear things that are not there.


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## Savjac

I am sorry but there is no bias here on my part. I really have never cared about cost vs performance.
I have heard some costly amps that just did not sound good. The Audio Research D100 being a very good example. There are a good number of quite expensive amps out there that just do not sound right, while at the same time there are a plethora of inexpensive amps that sound wonderful, remember the NAD3020, that thing got the soul of the music right. 
The differences may be subtle and take time to show themselves, but they are there if one listens. 

As one great mind said, Not everything that can be counted counts, and not everything that counts can be counted.


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## NBPk402

Not sure how to respond in the poll.

I believe all amps sound the same but... I believe if you are comparing 2 dif amps that you can hear a dif due to capacitance, resistance of wires and also inputs and output not compatible.

Example... Years ago I had a Audible Illusions preamp and a Classe DR10 amp.. I could swap speaker wires, interconnects, dampening mats etc and hear a night and day dif. When I inserted a Classe 6 preamp into the mix none of the above made a dif at all. I had read and I am a firm believer of the output of the preamp and the input of the power amp being matched or you will be subject to audible dif in cables. When i look for a power amp I want a input impedance that is as low as possible to negate audible cable dif.


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## Sonnie

Savjac said:


> I dunno, to me this seems like a counter argument. If we cannot measure it, it cannot be real. That is a bit like happiness or sadness, hope or doubt, if we cannot measure those things how does one quantify them ? Can we measure how much soundstage an amp will produce ? How deep or wide will the sound be ? And no we are not changing anything else but amps in this thought process. How about dynamics, I understand that the Class D amps have tremendous power for the bottom end of a speaker system as there is so little power wasted in the transfer but the top end is not quite as nice. There are differences all over, to deny them because we cannot measure them...today anyway, is probably not correct.


It is not an argument at all... it is merely a fact that had nothing to do with measurements. He could not "hear" a difference. Did you read the article at all? :whistling:


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## J&D

I was fortunate to be able to participate in and setup some very interesting blind comparisons back in the late 80's, early 90's. It all began when I wanted to put my hard earned cash down on a certain Harman Kardon amplifier and was chastised for even suggesting this. Why would I want to waste my money when I had the ability to score custom hand built mono-blocks at cost? Well, the reason was simple, the H/K at cost was about $600. The custom mono's were still $5K apiece. We setup the test and not a single person in the group including the resident golden ears could do better than 50/50. Case closed and my stance has remained ever since.

Of course there were still several skeptics that participated in the experiment and came up with many reasons why the test was not valid. So, over the course of several weeks I took every opportunity to stealthily disguise my lowly amp by placing it another room and leaving the very pricey amplifiers in full view. It was amazing how many incredible compliments the H/K then received from these same skeptics. Velvety, finely textured, revealing of every last musical nuance......... We are after all human and we often hear what our brains tell us we are hearing. 

Does it matter that you can hear a difference between amplifiers? Of course it does. That is one of the most entertaining parts of this hobby and the single largest reason we have so many options to choose from. I love this hobby.


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## primetimeguy

Savjac said:


> I am sorry but there is no bias here on my part. I really have never cared about cost vs performance.
> I have heard some costly amps that just did not sound good. The Audio Research D100 being a very good example. There are a good number of quite expensive amps out there that just do not sound right, while at the same time there are a plethora of inexpensive amps that sound wonderful, remember the NAD3020, that thing got the soul of the music right.
> The differences may be subtle and take time to show themselves, but they are there if one listens.
> 
> As one great mind said, Not everything that can be counted counts, and not everything that counts can be counted.


The biggest bias is not willing to accept the idea that a bias exists that you are not aware of and is beyond your control.


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## Sonnie

J&D said:


> So, over the course of several weeks I took every opportunity to stealthily disguise my lowly amp by placing it another room and leaving the very pricey amplifiers in full view. It was amazing how many incredible compliments the H/K then received from these same skeptics. Velvety, finely textured, revealing of every last musical nuance......... We are after all human and we often hear what our brains tell us we are hearing.


That ain't even right... but I got a great chuckle out of it (more than once). 

Velvety? Seriously? Someone has really created this term to describe a sound and there are others who can actually hear it too? :rolleyesno: Don't get me wrong... there are terms I have heard numerous times that I can somewhat relate to, such as warm, laid back, harsh, etc... (more simplified I guess), but velvety, finely textured must be terribly unique to only the golden eared folk... and apparently fictitious according to your sneaky little test.


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## Savjac

Indeed I have read the article, have read much of Tom and Peter's writings over the years and and fully disagree with their findings. I do not think I have much of a bias, maybe I do, but having heard differences, I have to go with that....and yet to think that those two gents who reportedly cannot hear a difference between amplifiers are paid reviewers and both have megabuck amplification systems. 
I find the information that they do not practice what they preach seems well odd.
Lets just say I am with the percentage of folks on here that can hear a difference.


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## Savjac

Sonnie said:


> Velvety? Seriously? Someone has really created this term to describe a sound and there are others who can actually hear it too? :rolleyesno: Don't get me wrong... there are terms I have heard numerous times that I can somewhat relate to, such as warm, laid back, harsh, etc... (more simplified I guess), but velvety, finely textured must be terribly unique to only the golden eared folk... and apparently fictitious according to your sneaky little test.


This is good too, 45% of the folks that voted can hear the differences and yet they get the roll eyes.
Hmm. You win.


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## Sonnie

Savjac said:


> Indeed I have read the article, have read much of Tom and Peter's writings over the years and and fully disagree with their findings.


So you fully disagree that those people could not hear a difference, even though they admitted they could not hear the difference? :scratch:




Savjac said:


> This is good too, 45% of the folks that voted can hear the differences and yet they get the roll eyes.
> Hmm. You win.


The roll eyes are for those using the particular term mentioned (velvety). FOR THE RECORD... I have NOT rolled my eyes at the 45% who claim they can hear a difference and I NEVER indicated such. It is amazing how someone can twist around what someone has said to try to make it suggest something else. I should give that a roll eyes... but I'll give you a wink instead. 

I agree that 45% "think" they hear a difference... and some may have actually heard a difference at some point in time because of abnormal circumstances and it was NOT under the same type testing as in the first post. I suspect if these 45% setup the same test comparison as in the first post that the percentage would drop... probably to about 0%. 

Did I still win? :R


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## J&D

Velvety as an official term of audiophilia was retired sometime around 1995 in which it was replaced with silky.


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## Sonnie

Hmmm... isn't silk smoother than velvet?


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## Savjac

Of course you win Sonny, you have more posts and those with the most posts wins... 

Although, I have seen Pink Floyd in person for the road shows of Dark Side of the Moon, Wish You Were Here, Animals, A Momentary Lapse of Reason not to mention Roger Waters on his own 3 times in addition to the above. Can I win something too ???

It is my sincere belief that I hear a difference, albeit I have not participated in a short term blind test. However 45% is a pretty big number and maybe one day we shall overcome, oh I hear a song in there.
I dont think that the posters are lying necessarily, however, those truths they espouse are also biases. Maybe they have a preconceived notion that there are no differences, so they hear none. I really hesitate to say anything bad, I just know I have heard the velvety, silky melt in your mouth chocolate covered mint sounds coming from some amps and ground peppered tapioca pudding from others. :innocent: Or not...Ok I never heard velvet but I have felt it once in a store...or was it in a Chrysler, not sure now.


I do draw the line at some claims in way of top secret nonsense names for cables, interconnects and some of the other stuff on the market that does seem to be snake oil. Having said that, I must confess that there is a bias in that statement mainly because I have not heard the end of the earth differences in some of these things being reviewed. I guess if I ever win a bazillion dollars in the lotto I will give them a try and maybe they will make a believer out of me...as soon as one of those super clocks gets all the bad juju from my room for only $19.95.


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## sub_crazy

Sonnie said:


> That ain't even right... but I got a great chuckle out of it (more than once).
> 
> *Velvety*? Seriously? Someone has really created this term to describe a sound and there are others who can actually hear it too? :rolleyesno: Don't get me wrong... there are terms I have heard numerous times that I can somewhat relate to, such as warm, laid back, harsh, etc... (more simplified I guess), but velvety, finely textured must be terribly unique to only the golden eared folk... and apparently fictitious according to your sneaky little test.


I like to use the descriptive term "Velveeta" when I feel an amp sounds cheesy to me.....is that OK :huh: :bigsmile:


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## Sonnie

Savjac said:


> Although, I have seen Pink Floyd in person for the road shows of Dark Side of the Moon, Wish You Were Here, Animals, A Momentary Lapse of Reason not to mention Roger Waters on his own 3 times in addition to the above. Can I win something too ???


You have already won if you have been all there and done all that. I definitely can't touch that... wish I could, but all I can muster up is one concert on the Pink Floyd Division Bell Tour.



Savjac said:


> I dont think that the posters are lying necessarily, however, those truths they espouse are also biases. Maybe they have a preconceived notion that there are no differences, so they hear none.


Keep in mind that Steve Zipser owned Sunshine Stereo, who sold very high end equipment. He had preconceived notions that he COULD hear a difference, until Tom came along and proved to him he could not. I can tell you that I would definitely want to hear a difference between a pair of $14,000 Class A monoblocks and a cheap $200 integrated amplifier, but he, his wife... nor any of his friends could hear a difference. Yet, we all know full well there was truly a difference in the amps... it was $13,800... and the Alephs looked prettier. :bigsmile:



Savjac said:


> I do draw the line at some claims in way of top secret nonsense names for cables, interconnects and some of the other stuff on the market that does seem to be snake oil. Having said that, I must confess that there is a bias in that statement mainly because I have not heard the end of the earth differences in some of these things being reviewed.


I am not going to say I will never be able to hear a difference in amps, cables or whatever, because I may get that opportunity to participate in a DBT one day and actually hear a difference. I think I have heard differences in the past between products, but those difference could be attributed to so many different variables and the differences were not determined under any type of organized testing setup. I do have a difficult time believing the differences some people claim, but that does not mean they are wrong or that it is not true, it just means I have a hard time believing it... to a point I occasionally poke fun at the thought. I think I am biased by what has been proven to me through tests that I have read about at this point, which I have zero problem admitting. It is what it is.



Savjac said:


> I guess if I ever win a bazillion dollars in the lotto I will give them a try and maybe they will make a believer out of me...as soon as one of those super clocks gets all the bad juju from my room for only $19.95.


I won't ever win a lottery because I won't be buying a ticket, but if I ever did come into a lot of money where I could spend it like there is no tomorrow :spend: ... I am sure I would search out the best looking amps around and pay whatever the price would be, but in searching for the absolute best sound I would be more concerned about what speakers to buy... which is what has made the most dramatic improvement for me.





sub_crazy said:


> I like to use the descriptive term "Velveeta" when I feel an amp sounds cheesy to me.....is that OK :huh: :bigsmile:


Absolutely, but you gotta tell us what cheesy sounds like. Does it sound like it has holes in it? :nerd:


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## Savjac

Yep I realize those guys have heard some of the biggest and best and that is what makes this all so difficult to rationalize. All these years I have listened intently and believed to the core I could hear differences. (Dont tell anyone but I thought I heard cable differences as well) If there are no audible difference this would cause a personal global re-think on my part. I no longer have access to a number of components so it may be awhile before I do any comparative listening again, but when I was in Savannah and Chicago, I brought home so many things and was very familiar with the listening systems qualities or lack thereof.

So for now I will stick to my beliefs until proven wrong to my satisfaction, which if done I will readily admit to. Jack is now open minded. Or maybe I do have holes in my head from the cheese factor, :blink:

Yes, I was a Floyd nut and did attend all of those concerts live. No other band even came close to the stunning performances and sound of that band and their members. I remember seeing Animals in Chicago at Soldier Field and when the band got quiet, you could hear a pin drop the audience was soooo hypnotized. Stunning.

I will spend the long weekend listening, and YES speakers make the biggest difference, and will try to determine if I can repeat changes in sound from swapping out other components. This should be enlightening

I do have zillions of cables, several Dacs, SS and Tube, SACD players music files so if you ever need a good Blind test no problems there. Most importantly I have a door on the room, keep the pets out.
Lastly...I dont buy Lotto either, guess that makes it a bit hard to win. I suppose if I knew the money actually went to some good, schools, poiice, libraries, music programs etc, I may buy a few. At this time I dont wish to fatten the political wallet anymore than it is, but that is another discussion.


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## DanTheMan

Some amps will definitely add an audible sound to your playback system. I've got a headphone amp that distorts on low impedance headphones, I've got my Emotiva that has an audible hum when all is silent(from my listening position, my tube amp has it's own unique character, and my t-amp has a treble boost with certain speakers and doesn't have deep bass(iow, it's an EQ as well lol).

So amps can make a difference if they are not as well designed--or designed to be inaccurate.


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## Savjac

There see, more positive proof, Dan knows that differences exist. Its a natural think, like gravy on taters or chicken gravy on a fried steak...whatever that is.

Anyway there are so many opinions for and against, some of us have to hold our ground. :T


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## Sonnie

No one has said that differences do not exist between two amps under the circumstances he referred to.

From the original post:

_Can we really hear a difference between two amps?

More specifically... between two amps that have been level matched in a controlled listening test. We are not talking about amps that have been modified or are driven beyond their reasonable limits.

I have leaned towards the camp of not being able to hear any significant difference between almost any two amps out there when played at moderate levels on the typical speaker system, unless there is something wrong with one or the other amp that might cause it to color the sound.

Granted... a low-end receiver may well have an issue driving a system of certain electrostatic speakers... or speakers with low sensitivity, especially if pushed to higher levels. There are going to be exceptions, but for the sake of this discussion, let's say we are using a pair of Klipsch RF-62 II speakers with a sensitivity of 97dB @ 2.83V / 1m ... or perhaps the Duntech Marquis speakers that Zipser was using above at 92db. _


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## J&D

DanTheMan said:


> Some amps will definitely add an audible sound to your playback system. I've got a headphone amp that distorts on low impedance headphones, I've got my Emotiva that has an audible hum when all is silent(from my listening position, my tube amp has it's own unique character, and my t-amp has a treble boost with certain speakers and doesn't have deep bass(iow, it's an EQ as well lol).
> 
> So amps can make a difference if they are not as well designed--or designed to be inaccurate.


No disagreement with any of these situations but what you are describing are differences in sound when an amp is driven beyond it's design capability. Or in the case of the Emo amp it is low level noise which could be introduced via a grounding problem, cabling or inherent to the amp itself. In most cases this type of low level noise almost always changes very little in amplitude compared to the input signal. So when driving an input signal to normal listening levels the noise is buried and usually inaudible (although many will claim to hear this low level noise as well). There have been several tests regarding low level noise audibility over the years. Specifically when comparing ADC's and DAC's quantifying their performance based on noise floor and resolution. Again complete level matched blind testing is the only way to completely eliminate any bias.

I think everyone understands that tube amps add distortion to the input signal. Some people obviously enjoy this distortion and prefer it over solid state amplification which in almost all cases today is distortion free regardless of the design. The important thing is to use any amplifier within the parameters it was designed to operate. This is critical to understanding why the results of these types of tests are always the same.


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## JerryLove

Savjac said:


> Although, I have seen Pink Floyd in person for the road shows of Dark Side of the Moon, Wish You Were Here, Animals, A Momentary Lapse of Reason not to mention Roger Waters on his own 3 times in addition to the above. Can I win something too ???


That depends. Did you see what amps he was using?


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## Savjac

Good question Jerry and no, you know I really did not see them, but they sure did sound good. I hope they used all the same amps so one side of the audience did not hear something different than the other side. Actually, they were all in surround sound, even DSOTM. Good stuff


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## Savjac

Sonnie said:


> No one has said that differences do not exist between two amps under the circumstances he referred to.
> 
> From the original post:
> 
> _Can we really hear a difference between two amps?
> 
> More specifically... between two amps that have been level matched in a controlled listening test. We are not talking about amps that have been modified or are driven beyond their reasonable limits.
> 
> I have leaned towards the camp of not being able to hear any significant difference between almost any two amps out there when played at moderate levels on the typical speaker system, unless there is something wrong with one or the other amp that might cause it to color the sound.
> 
> Granted... a low-end receiver may well have an issue driving a system of certain electrostatic speakers... or speakers with low sensitivity, especially if pushed to higher levels. There are going to be exceptions, but for the sake of this discussion, let's say we are using a pair of Klipsch RF-62 II speakers with a sensitivity of 97dB @ 2.83V / 1m ... or perhaps the Duntech Marquis speakers that Zipser was using above at 92db. _


Good Number of qualifiers in that statement and a nice "Granted there are going to be exceptions"
Oh and a good one.." I have leaned towards the camp of not being able to hear any SIGNIFICANT difference between ALMOST any two amps out there when played at MODERATE levels blah blah blah.

Not gonna change my mind, i CAN hear the differences between SOME amps blah blah blah. We are saying the same thing only different. Y'all will read it to fit a certain belief as will I. 

Life is good when we have choices. Besides there literally has to be sonic differences as they are oft times constructed so differently, the ODDS are on my side.


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## Sonnie

Hey... not the first person that I know of is trying to get you to change your mind. A man's opinion changed against his will is of the same opinion still. Yet, it would be very interesting to see your response in a DBT as was conducted in the first post. :gulp: 

We have always been talking about the typical norm, not the rare exceptions. I think everything you have brought up has not given any consideration to the first post, which is what the jest of the thread is about and why I keep pointing back to it. I read like it is and lean towards the facts that have been proven thus far. :dontknow:


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## JerryLove

There's basically 3 qualifiers.

The amp cannot be designed to color sound.
The amp needs to be correctly built (which is most commercial amps)
The amp cannot be asked to do more than it is actually capable of doing (run 1ohm loads (excepting amps that can do this like many McIntosh or Krell amps) or driven to clipping)

I think it should be really obvious that an AVR amp asked to run a 1ohm load @300w will catch fire and fail. Yea: it will sound different.


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## recruit

Like BANG! Lol!


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## terry j

Savjac said:


> I dunno, to me this seems like a counter argument. If we cannot measure it, it cannot be real. That is a bit like happiness or sadness, hope or doubt, if we cannot measure those things how does one quantify them ? Can we measure how much soundstage an amp will produce ? How deep or wide will the sound be ? And no we are not changing anything else but amps in this thought process. How about dynamics, I understand that the Class D amps have tremendous power for the bottom end of a speaker system as there is so little power wasted in the transfer but the top end is not quite as nice. There are differences all over, to deny them because we cannot measure them...today anyway, is probably not correct.


But we can measure these things, or at least you claim to be able to.

You are sure you have heard differences between amps (soundstage or dynamics say, just to point out these 'unmeasureables').... that automatically implies you measured these, with your ears. (and make no mistake, our senses are a suitable measurement system here. "Is there a tree over there?" You take a look-a measurement in other words-and can then answer the question)

That was just an aside to remove what I suspect was your 'error', that it requires external measurement devices to detect things. (we have done a pretty good job over the millenia without exotic measurement gear).

That, in essence, is what a dbt is, a measurement process. Here is an stimulus, now compare that with this next one.

I think the biggest problems we run into with these type of discussions is how little experience people have with these hidden or unconscious biases we all have. Sure, we might think, feel or know we have no bias..but how often is that ever tested?? I don't think people know how pervasive these unknown biases are. And people will never know till they test it. I mean I get it, people can be completely sure they are completely uninfluenced but never go on (even out of intellectual curiosity) to educate themselves by testing if they do or do not have these biases.

I can tell you, involve yourself in even a half well done blind test and your foundations will rock. This is not to say there are no differences at all, but I can pretty well guarantee you that these vast day and night, easily heard differences will completely disappear.

Level matched and driven without clipping are needed. Ok, to some the not clipping (driven within limits) may seem to be a way to 'ensure' an outcome of all sound the same. Not really as already explained, but there is an additional point about that that has not yet been raised...the last few pages anyway!

IF there is a difference between amps because one is over driven, _all_ that is saying is you need more power, NOT some exotic or more audiophile amp. Some seem to use that as a backdoor way to justify a _better_ amp (whatever that is) rather than simply a more powerful amp. The argument here is that there is no better, just different abilities to drive the speakers to whatever volume required.

I just kinda get stuck on the 'arrogance' of people maintaining they have no biases without ever finding out. Sure, it's all well and good to simply maintain something (you know, the earth is flat) yet have absolutely nothing on which to base that stance. Hop on a psychology forum and tell them you have no biases and your conclusions are not influenced in any way from your past experiences in life. (that was the general you by the way) It would be interesting to see what the reaction would be!

So the measurement procedure is to listen to the amps without knowing which is which. If they can be correctly identified then they have been measured to sound different. 

The test uses the exact same bit of measuring gear that is used when people hear differences sighted. That measuring gear should also be good enough to do it unsighted then no?


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## Sonnie

Very well said terry.

And Jerry... I wonder what percentage of solid state amps manufactured would fall into those three qualifiers? Obviously it would be a total guess, but I have to believe that most amps built today would be included, with only a few exceptions of the poorly designed amps that probably not a lot of folks are buying.


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## Savjac

I say I can hear a difference, although I agree I have not been in a double blind. However, this statement is not so cool..

"I just kinda get stuck on the 'arrogance' of people maintaining they have no biases without ever finding out. Sure, it's all well and good to simply maintain something (you know, the earth is flat) yet have absolutely nothing on which to base that stance. Hop on a psychology forum and tell them you have no biases and your conclusions are not influenced in any way from your past experiences in life. (that was the general you by the way) It would be interesting to see what the reaction would be!

So it seems if I disagree with what a percentage of others say, and because its different I am biased...well ok I may be biased by my experiences but I certainly am not arrogant. Please do not go to the location where believing in something without proof on which to base a stance. Much of life is believing in something which we do not have concrete proof. 
Now obviously my conclusions are based on experience, as are everyone's here I am no different, my opinion is different and since my opinion is similar to just under half the folks that have taken this poll, I guess that opinion is pretty popular. All these opinions work 2 ways, ours and theirs. Because someone has not proven something means little in way of science today. Many things are yet unproven. Higgs Bosen sound familiar or maybe something a little more everyday...memory, can we show how memory works, not just where it might be stored. And if we cannot prove how folks recall short, long term does that mean it does not exist ? The brain and body do work on electrical impulses, we should be able to hook us up to some gizmo and voila, an answer. Even the great Thomas Edison admitted he did not know everything by saying he did not fail,he just found 10,000 ways that dont work. It would be sheer hubris to admit we can tell everything that is going on in the reproduction of sound because we dont. Things change daily....just wait and someone will get it.


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## primetimeguy

Fantastic post!



terry j said:


> But we can measure these things, or at least you claim to be able to.
> 
> You are sure you have heard differences between amps (soundstage or dynamics say, just to point out these 'unmeasureables').... that automatically implies you measured these, with your ears. (and make no mistake, our senses are a suitable measurement system here. "Is there a tree over there?" You take a look-a measurement in other words-and can then answer the question)
> 
> That was just an aside to remove what I suspect was your 'error', that it requires external measurement devices to detect things. (we have done a pretty good job over the millenia without exotic measurement gear).
> 
> That, in essence, is what a dbt is, a measurement process. Here is an stimulus, now compare that with this next one.
> 
> I think the biggest problems we run into with these type of discussions is how little experience people have with these hidden or unconscious biases we all have. Sure, we might think, feel or know we have no bias..but how often is that ever tested?? I don't think people know how pervasive these unknown biases are. And people will never know till they test it. I mean I get it, people can be completely sure they are completely uninfluenced but never go on (even out of intellectual curiosity) to educate themselves by testing if they do or do not have these biases.
> 
> I can tell you, involve yourself in even a half well done blind test and your foundations will rock. This is not to say there are no differences at all, but I can pretty well guarantee you that these vast day and night, easily heard differences will completely disappear.
> 
> Level matched and driven without clipping are needed. Ok, to some the not clipping (driven within limits) may seem to be a way to 'ensure' an outcome of all sound the same. Not really as already explained, but there is an additional point about that that has not yet been raised...the last few pages anyway!
> 
> IF there is a difference between amps because one is over driven, _all_ that is saying is you need more power, NOT some exotic or more audiophile amp. Some seem to use that as a backdoor way to justify a _better_ amp (whatever that is) rather than simply a more powerful amp. The argument here is that there is no better, just different abilities to drive the speakers to whatever volume required.
> 
> I just kinda get stuck on the 'arrogance' of people maintaining they have no biases without ever finding out. Sure, it's all well and good to simply maintain something (you know, the earth is flat) yet have absolutely nothing on which to base that stance. Hop on a psychology forum and tell them you have no biases and your conclusions are not influenced in any way from your past experiences in life. (that was the general you by the way) It would be interesting to see what the reaction would be!
> 
> So the measurement procedure is to listen to the amps without knowing which is which. If they can be correctly identified then they have been measured to sound different.
> 
> The test uses the exact same bit of measuring gear that is used when people hear differences sighted. That measuring gear should also be good enough to do it unsighted then no?


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## DanTheMan

With all the qualifiers, no doubt you guys are correct.

Anyway,
It is the Emotiva amp that hums. They told me it might be audible b/c my speakers are fairly efficient. I was actually shocked that it is. With music on though... It's certainly not much of an issue. Can't say it's detrimental to my enjoyment. I just wanted more power b/c I had clipped my old amp a few times. Haven't had that happen on the Emotiva. The hum that one of my sub amps make gets my goat a bit though.

The T-amp made sonic compromises to be portable/efficient. Not a bad amp even if not HiFi. Funny that so many were crowning it, but it's certainly not sonic magic. I didn't think it would be though. Just wanted a boom box.

Dan


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## J&D

I am a bit curious to find out if any of those that responded in the affirmative have ever participated in a blind comparison. Another poll could shed some interesting light on the results here.


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## JBrax

Very thought provoking thread and an excellent read. Subscribed.


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## JerryLove

Sonnie said:


> And Jerry... I wonder what percentage of solid state amps manufactured would fall into those three qualifiers? Obviously it would be a total guess, but I have to believe that most amps built today would be included, with only a few exceptions of the poorly designed amps that probably not a lot of folks are buying.


The third qualifier cannot be said of an amp: It can only be said of an amp-speaker pair. 

I think most commercial separates would meet #1 and #2. I think that the exceptions would be the exotics.


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## chashint

I may have to reconsider whether amps sound different or not. If an amp produces audible hiss when there should be silence I would say that would meet all of the qualifiers and would indeed sound different and be easily identified by the most casual observer.
Or would that put Emotivia in the poorly designed category ?


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## DanTheMan

I don't know that I'd even say it's poorly designed. It does kind of stink that my old HK3490 doesn't produce an audible hum with the same speakers. I don't recall my Onkyo doing it either. None the less, the Emotiva has a little more headroom--or it least it should. Anyway, I could have returned this and got a different one, but I didn't.
They told me I may need to get the cheaper amp or I may hear a hum with my speakers. They said it was d/t the higher gain on this one. :/

Dan


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## Sonnie

DanTheMan said:


> It is the Emotiva amp that hums. They told me it might be audible b/c my speakers are fairly efficient. I was actually shocked that it is. With music on though... It's certainly not much of an issue. Can't say it's detrimental to my enjoyment. I just wanted more power b/c I had clipped my old amp a few times. Haven't had that happen on the Emotiva. The hum that one of my sub amps make gets my goat a bit though.





chashint said:


> I may have to reconsider whether amps sound different or not. If an amp produces audible hiss when there should be silence I would say that would meet all of the qualifiers and would indeed sound different and be easily identified by the most casual observer.
> Or would that put Emotivia in the poorly designed category ?


Would there be any benefit in Emotiva creating an amp that performs better with lower sensitivity? If not then it would have to be considered a poor design, would it not?

If I go to a DBT and hear hum in one amp and none in the other, no doubt I am going to hear a difference. If one of the amps were mine then I would be able to identify the amps when comparing them. I would not want to buy an amp with audible hum and would look for one that works best with my speakers, which is apparently what I did. 

I am having to replace one of my Behringer EP2500 amps because it developed a hum... one of those that prevented the sub driver from performing as it should. However, I have the Emotiva XPA-1 monoblocks powering my MartinLogan Prodigy's and have no hum, but the ML's are a little more difficult to drive too.

I purchased my XPA-1's because I like how they look, I wanted a lot of power, Emotiva is a sponsor and I got a good deal on them. Let's suppose that I was in the market and did not care what the amps looked like... Emotiva was not a sponsor and the market was wide open for me. I could afford any amp I want, but I prefer to get the best bang for the buck, because like I said, I don't care what they look like. I just want them to work, sound like they are supposed to sound and power my speakers like they should. What makes a $25-30,000 pair of Krell 600e's (1200wpc) sound that much better than using a pair of $1,700 XPA-1's (1000wpc) or a pair of EP2500's in a bi-amp (600w + 600w per speaker) setup for less than $600? Should I be able to hear a difference between the three?




J&D said:


> I am a bit curious to find out if any of those that responded in the affirmative have ever participated in a blind comparison. Another poll could shed some interesting light on the results here.


I have only ever heard/read about DBTs where participates could not tell a difference between two amps, but I would like to participate in one anyway just to see if I can hear a difference.


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## Savjac

*What makes a $25-30,000 pair of Krell 600e's (1200wpc) sound that much better than using a pair of $1,700 XPA-1's
*

I dont think it fair to say better necessarily, but Different, most probably. This will of course depend on the listener and interaction between the speaker and the amp.


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## Sonnie

That is why we need DBT, to help determine if there is a difference and be able to identify it... describe what that difference is. Why is it different, especially if it is not for the better. Why does that difference cost so much, especially if it is not for the better. Why are there no DBT with anyone recording and confirming these differences? 

I know that I have a very long list of amps I have tried and I cannot remember ever being able to hear a difference... including receivers. What made the most difference to me was speakers. It would be great to be able to hear a difference if it were better. I would love to have an experience equal to that of finally finding the right speakers.


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## Savjac

You know that is a good point but I personally do not believe in DBT. It just is not how our brains work. There is a reason that most people are said to do no better than chance.

The human brain is not good in that type of situation, look at trying to remember names, directions, exact colors, numbers, grandkids names (JK). Human brains are pretty good visually, it remembers faces, photos, parts of movies, locations etc, but can be easily tricked there on occasion as well. This is one reasons that witnesses to a crime are not as reliable as once thought.

We have to live with something for awhile in order to drink in all the nuances. Can you imagine getting married based on a double blind Date ? Or buying a house based on a quick inspection without getting into the meat of it...a car, now we even get a 30 day evaluation on many audio components because even the manufacturers admit any given item, inclusive of amplification, may nor work for any given user. 

I have heard differences in amps, some interconnects and cables, pre amps, DACs etc and I know this as a fact. There can be no way to convince me otherwise.


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## Sonnie

It is how my brain works for comparing amps. My brain works different ways depending on the situation. No doubt everyone's brain works differently. I would need a DBT for this to be proven to me... plain and simple. I do not trust my brain in this situation (nor a lot of others for that matter). A DBT would be the ONLY way I could be convinced without any doubt I was hearing a difference. I am willing to submit to one to see if it were possible to hear a difference... I am certainly not going to avoid it because of fear I might change my mind. But hey... to each his own. You believe you can hear a difference and you don't want anything to take that away from you... you don't want anything to change your mind... so you'll have to take back that statement about being open-minded. :bigsmile:

As far as comparing DBT of amps to DBT of getting married. :rofl: That was just too funny. :rofl2:


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## Savjac

Yeah I figured the marriage part would stick out for some of us.
I am sorry I gave the wrong impression about me, I really am open minded, but, and as we know everyone has a big but, I truly am willing to listen to some type of realistic test to bring my mind to rest about these issues. No body wants to be wrong really but for me this is not a life and death situation and as such there is no fear there. I absolutely love knowledge, truth and the American Way although I cannot jump tall buildings in a single bound.....yet :whistling: 

What bothers me about the DBT also is that is seems to be so definitive, no one has been reported as coming away defeating it if we are to believe the reports. This to me seems totally against the odds and as such there may be something the matter with the test that removes the possibility of success, the $ 10,000 prize so willingly offered seems to raise a red flag for me.

Like you I also am a fan of Emotiva XPA amps and own them, along with a couple Emo subs, a couple Velodyne subs, Martin Logan speakers and a zillion other things that are at the same time fun and frustrating to play with. Tube Dac or SS Dac, iTunes or JRiver Media, Mac or PC, lions and tigers and bears oh my.

I suppose there will be a need one day to get into a comparison again, just to see if the tuned ears are still in tune eh ???

Note: One thing I am pondering is an IB sub, for that I doubt that amplifier differences will mean much as long as they have the power and quality to so the job for many years, I doubt I will be so picky. Getting myself to do this may be the biggest of problems but with the new house comes a dedicated room and huge space below. Hmmmmmmm.


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## chashint

The DBT is the only meaningful way to subjectively evaluate sound whether it be amps, speakers, wires, or sources.
Not believing in the DBT does not change that it is legitimate.
In DBT the listener does not even know if "A" is always the same component being switched in/out, the tester may give the option "A" / "B" where A and B are the same component.
To argue against the method being valid is pure audiophile baloney.


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## J&D

Savjac said:


> You know that is a good point but I personally do not believe in DBT. It just is not how our brains work. There is a reason that most people are said to do no better than chance.
> 
> The human brain is not good in that type of situation, look at trying to remember names, directions, exact colors, numbers, grandkids names (JK). Human brains are pretty good visually, it remembers faces, photos, parts of movies, locations etc, but can be easily tricked there on occasion as well. This is one reasons that witnesses to a crime are not as reliable as once thought.
> 
> We have to live with something for awhile in order to drink in all the nuances. Can you imagine getting married based on a double blind Date ? Or buying a house based on a quick inspection without getting into the meat of it...a car, now we even get a 30 day evaluation on many audio components because even the manufacturers admit any given item, inclusive of amplification, may nor work for any given user.
> 
> I have heard differences in amps, some interconnects and cables, pre amps, DACs etc and I know this as a fact. There can be no way to convince me otherwise.


I am not trying to convince you that you cannot hear a difference but what you just described regarding how our brains work actually further solidifies the argument for DBT as the only way to prove if we actually heard a difference or not.

I completely agree that our brains have a very poor memory for very slight differences or to put it into audio terms very small nuances in a music track. I am not saying we cannot hear them when they are happening I am saying that our recall of that sound is just not that great. Thus, if you listen to some gear at one point in time and then go listen to that same gear again at a later date our memory of how that exact same gear sounds can even be very hard if not impossible to recall. 

So the only way you can truly make a comparison between two amps is to listen to them at as close to the same time as possible under the exact same conditions - room, speakers, source material, source components, level matched and have no preconceived bias take part in that comparison (blind). Otherwise any other comparison at all is fairly useless. Even if you are very familiar with your room, speakers, source material, source components and your conduct the test your own bias will play too large a role to make a valid comparison and everyone has it. Bias that is. 

I have participated in enough of these tests and sold more than my share of gear to understand how people purchase. First off, if you bring something home you are more likely to keep it in the end than if you just audition in the store and walk away. If you have to pack it and ship it back at your own expense you are even less likely to send it back. What you are told (or the research you do) about that gear will always play a huge role in how you perceive that gear to sound and perform. There is a reason hi-end shops have separate listening rooms with gear separated by price and/or brand. Some shops will let you mix and match to a limited degree for comparison purposes but in the case of amplification just try to haul one of their low end integrated amps or better yet a higher end AVR into the "salon" and wire it up to their flagship speakers. Even if the AVR has sufficient power to drive them to reasonable levels in almost all cases they will never let you do that let alone connect up an ABX switch between the AVR and their $50K/pair mono blocks. 

This is why a GTG setting up a fairly reasonable DBT can be invaluable to someone who has never participated in such an event. Most of these have been with speakers and subs though which can be almost impossible to properly conduct. It is hard to hide the physical aspects of the speakers themselves and proper setup and calibration can be very time consuming. Amp or source component comparisons can be done much more easily as they equipment is easy to hide and the setup and calibration is very simple. 

Maybe HTS or an ambitious member would volunteer to host one of these GTG's. Invite someone with credibility in the industry to oversee the setup and conduct the testing. Call it the ultimate HTS amplifier shootout.


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## Sonnie

I am not sure how a DBT removes the possibility of success in hearing a difference, UNLESS there is no difference. I am not aware of anyone who has proven any fault with the DBT test methods that have proven no differences can be heard. I really wish more DBT would be done, so that if there is a difference, we could know without a doubt there is a difference. 

I have to rationalize the best I can here. If I am unable to hear a difference in my home, then I certainly am not going to spend thousands upon thousands more because someone else says there is a difference. I would want definitive prove that there is a significant improvement (to my ears) in the sound... like what I heard when I changed speakers.


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## Sonnie

J&D said:


> Maybe HTS or an ambitious member would volunteer to host one of these GTG's. Invite someone with credibility in the industry to oversee the setup and conduct the testing. Call it the ultimate HTS amplifier shootout.


That would truly be awesome.

If we could get someone like Ed Mullen of SVSound, who has reviewed many amps in his day and has heard numerous systems... but does not sell amps and has no stake in whether there is a difference or not. I think he could assure an unbiased setup between amps. Of course I am sure there are plenty of other qualified professionals with sufficient credentials... he just came to mind out of the gate. I am surprised I remembered him so well. I wonder if I would have remembered him in a DBT. :devil:


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## chashint

I will go so far as to say that two amps cannot be reliably distinguished from each other in a DBT.
That does not mean correctly identifying brand XX or brand YY, that means reliably identifying a difference in sound between the two.
When any one of the two are switched between themselves there will be equal guessing that the switch is between brand XX and brand YY as there is when the components are actually switched.

Processors may sound different since there is "processing" taking place, amplifiers and wires do not process the sound. Hence they sound the same.


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## Sonnie

I am reviewing a Denon 4520 right now and plan to connect the amps of that receiver to my MartinLogan setup. Although my ML's are rated at 4 ohms, the upper end is as low as 1 ohm, so I cannot say that the 4520 is necessarily the proper choice to drive the ML's, yet I do not expect I will notice a difference, unless maybe I am trying to hit 125db SPL in the room... perhaps the 4520 will run out of steam. Then again, maybe not, because I plan to bi-amp the mains, which are the ones that present the most difficult load. The thing is at normal listening levels I don't think I will notice a difference in the sound, although I will admit there may be a difference. I don't and won't know for absolutely sure because I have no valid way of testing it. The only way I could know for sure is to conduct a DBT between the two.


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## JerryLove

chashint said:


> I may have to reconsider whether amps sound different or not. If an amp produces audible hiss when there should be silence I would say that would meet all of the qualifiers and would indeed sound different and be easily identified by the most casual observer.
> Or would that put Emotivia in the poorly designed category ?


That's the signal-to-noise ratio or "noise floor". Assuming it's actually being introduced by the amp; it's likely a problem with the amp. There's actually considerable discussion on Emotiva threads regarding this where some report hiss and others do not. In cases where it has been reported: I believe the power transformer was identified as the issue and Emotiva replaced it under warranty.

It's also possible to be introduced pre-amp. The signal coming into the amp is not truly silent. If you add enough gain, you'll hear hiss on anything. It could be an interconnect or some component earlier in the chain.

All that said. Unless the hiss is so loud you are hearing it at your listening position and at normal volume settings; you are unlikely in the extreme to notice any difference during actual playback.

But yes: if the Emotiva is hissing and another amp at the same spot is not hissing, then there's a problem with the Emo. 

For example: http://emotivalounge.proboards.com/index.cgi?action=display&board=speakers&thread=9886&page=1#156420


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## chashint

^^^
Agreed.


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## Savjac

I think we live in the real world and not a DBT world, although I could be wrong on that since I have yet to find a life instruction booklet. Anyhow, here is a neat snip taken from the Clark test.
_
Does this mean all amps sound the same in a normal install?

No. Richard Clark is very careful to say that amps usually do not sound the same in the real world. _


BUMMER. But next we may have to discuss the differences between Coke and Pepsi...if there are any....


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## primetimeguy

Savjac said:


> I think we live in the real world and not a DBT world, although I could be wrong on that since I have yet to find a life instruction booklet. Anyhow, here is a neat snip taken from the Clark test.
> _
> Does this mean all amps sound the same in a normal install?
> 
> No. Richard Clark is very careful to say that amps usually do not sound the same in the real world. _
> 
> 
> BUMMER. But next we may have to discuss the differences between Coke and Pepsi...if there are any....


But if you include the rest of the answer "The gain setting of an amplifier can make huge differences in how an amplifier sounds, as can details like how crossovers or other filters are set. When played very loud (into clipping), the amplifier with more power will generally sound better than a lower powered amp." It makes sense. In the real world when swapping out components users tend to not level match or keep all other settings the same. And we all agree that driving an amp into clipping will sound different. 

I think what he is trying to say is under a true controlled DBT test there are no differences. But when people try to compare them on their own the don't control all of the variables and therefore they do not sound the same.


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## JerryLove

Savjac said:


> I think we live in the real world and not a DBT world,


So you don't believe that DBT's happen in the "real" world? Is there some sort of "we are living in the matrix" comment in there?



> Anyhow, here is a neat snip taken from the Clark test.


Yes. Even neater when, as pointed out by another poster already, you include the couple of sentences that follow it.


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## Savjac

No the DBT does not happen in the real world, in the real world we listen to the system and do not add filters, adjust crossovers to make the amplifiers all appear to be the same. In the real world we hook em up and play.
A real world test would be to use the same system one always uses and insert the amps with no messing around. This will tell us what an amp, in a real world system will sound like. His definition is way to shallow, in that yes they sound different, unless we make them the same which he does by setting rules to ensure everything is well controlled. We do not base our decisions on that, we know what equipment we use and make a purchase on that point, we don't buy and amp and then try to correct everything else in the system to make the amp sound right.

If and note I say if, all amps sounded the same, there would be no reason to even listen at the store, just get one that seems to have enough power and go home. We could all save thousands I am sure. But that is not the case, even the naysayers have quite high end gear, now why would they do that if they can prove a cheap Pioneer sounds the same as a multibuck tube amp ?? The facts of what these guys actually do with their money tends to make their test look a bit silly.


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## JerryLove

Savjac said:


> No the DBT does not happen in the real world


That's odd; because I've participated in several and I'm pretty sure I am a real-world creature. 



> in the real world we listen to the system and do not add filters, adjust crossovers to make the amplifiers all appear to be the same.


What are you talking about? A DBT amp test only requires that the amps be level matched (you know; by turning that volume knob-thing until they are putting out the same volume?) and then some way to switch between them. 

I have no idea what you are talking about with filters and crossovers and such. Perhaps that's the part that's in the fantasy world you were discussing.



> If and note I say if, all amps sounded the same, there would be no reason to even listen at the store, just get one that seems to have enough power and go home. We could all save thousands I am sure.


I couldn't save much because that's exactly how I buy amps these days. Mind you I prefer the Yamaha over the Crown (when I don't need <4ohms) because the Crown has gaudy lighting; and I'd prefer a modern McIntosh over my Yamahas because 1) it's much prettier and 2) it can be turned on by remote/12v without having to resort to switched outlets.

I've had Krell and McIntosh and a few others: but most of my gear (that's not powered by the AVR) is running off Yammy P-series amps right now. If I were to add an external amp to the bedroom it would likely be an Emotiva (because of the appearance and 12v trigger).

And I've listened to the exact same speakers on multi-thousand dollar amps and my couple-hundred-dollar amps. No audible difference.


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## AudiocRaver

I do not have Super Golden Ears, but I believe they are Pretty Good Ears. There have been numerous times I thought I heard something - a change in my system, a difference between components that should sound the same, whatever - the next step for me was always curiosity, "OK, what is going on here, is this real? Is the apparent change/difference reproducible, maybe even explainable? Am I imagining this somehow?" Why? So I can avoid making changes or spending money unnecessarily, or - even worse - sending someone else on a wild goose chase based on an error.

So an investigation always follows. Once I discovered that one side of a graphic EQ had gone bad, was running essentially bypassed - good catch. Once I discovered that a budget power amp with good paper specs could run loud for awhile sounding fine, then distort audibly during a quiet passage while it cooled - another good catch. Many other times I thought I heard something, looked into it, ended up humbled at having to admit I had imagined it, Pretty Good Ears and all. All those other experiences showed me how unreliable auditory memory can be.

I fully respect that there are those who simply want to believe they hear something and care nothing about proof or validation. For audio gear decisions made in a vacuum, it is fine to make those choices without validation. When it starts to affect other people - their money, their time or trouble, then it seems the kinder approach to be able to validate the choice. My experience convinces me that in probably 99% of DBT-unverified "I hear a difference" instances, for power amps, cables, etc, under the conditions of proper design & use as previously discussed, the difference is imagined. The other one percent? Super Golden Ears &/or ESP.

I _want_ to believe there are Super Golden Ears out there who can hear the difference between amplifiers. It gives me something to aspire to. If I ever claim to have reached Super Golden Ears status, I will expect to be able to back it up reliably through DBT so I can be confident I am really hearing it. That way, I can tell someone "A sounds better than B" with confidence that it really does. If I never intend to communicate unvalidated findings, then it doesn't matter.


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## tonyvdb

Its been my experience that the people that believe that there is an "audible difference" in amps that are on the same ground meaning that they are well made and of the same design not Tube or ICE or magnetic field for example are the same people who believe that spending ridiculous amounts of money on interconnects or power cables will make an audible difference. 
Ive found that when someone spends alot of money and then has to justify it or it makes them feel good it has little to do with what they hear but more just a feeling. If you think you hear a difference the more power to you but in all reality and in actual tests this should not be the case if the manufacturers build to correct specifications.


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## terry j

Savjac said:


> I say I can hear a difference, although I agree I have not been in a double blind. However, this statement is not so cool..
> 
> "I just kinda get stuck on the 'arrogance' of people maintaining they have no biases without ever finding out. Sure, it's all well and good to simply maintain something (you know, the earth is flat) yet have absolutely nothing on which to base that stance. Hop on a psychology forum and tell them you have no biases and your conclusions are not influenced in any way from your past experiences in life. (that was the general you by the way) It would be interesting to see what the reaction would be!
> 
> So it seems if I disagree with what a percentage of others say, and because its different I am biased...well ok I may be biased by my experiences but I certainly am not arrogant. Please do not go to the location where believing in something without proof on which to base a stance. Much of life is believing in something which we do not have concrete proof.


You missed the point.

We are *ALL* biased and influenced by the sum and cumulation of everything before us in our life. It has absolutely nothing to do with you having different thoughts than others as being proof of being biased.

Being human is sufficient proof you have bias, nothing more. Give us, in whatever amount of detail you are able or feel the need to, all the points of fact and data you have that shows us not only that you investigated whether you have biases or not (include details of the experimental procedure) but also that indeed, at least in the case of amplifier differences that you are completely unbiased.

If, as I suspect you have not done anything of the sort then it is nothing more than a claim on your part of being 'special'. You are indeed different from every other being on the planet.

Your moral indignation and sputtering actually did little to disprove every part of my post you quoted, rather it instead proved my post completely. And I am even more stuck on your arrogance I am afraid.






Savjac said:


> You know that is a good point but I personally do not believe in DBT. It just is not how our brains work. There is a reason that most people are said to do no better than chance.


I am not even sure what this sentence says. Strangely tho, there is something accurate in there and even more strangely one that runs counter to the point you are trying to make. You are correct it is not how our brains work _precisely_ because it intends to remove the biases which (yourself excluded it seems) we all fall prey to.

You claim also to be intellectually curious and honest, so is it at all possible another plausible reason most people seem to return chance results is that most amps not driven past their limits do indeed sound alike?? Why was that possibility not part of your list of plausible explanations? Why instead did you run to it (sounding alike) being some proof that dbt's don't work?

Can you show us your investigations into why dbt's don't work. Or is that just another 'just cause I say so' type of thing.



> I have heard differences in amps, some interconnects and cables, pre amps, DACs etc and I know this as a fact. There can be no way to convince me otherwise.


We all agree with you, and all agree it is a fact. We have no doubt that for a fact you have heard differences between amps, pre's and cables et al.

There is no need to convince you otherwise nor do we want to. To do so would be to call you a liar, we believe you when you tell us you have heard differences. We do not think you are lying.

Look up something done by Jon Dunlavy, you have probably heard of him. Equally, if you know of him you also respect him and his contributions to audio. His views on cables (NOT AMPS AS BEING DISCUSSED HERE) (, sorry bout caps lock) but as you will see, none the less pertinant.

ALL he had to do was to get his assistants to hold up and show to the listening audience some python sized cables behind his speakers.

Not say a word, do nothing else. Then they would bend down out of sight.

It was never said of course, apart from the holding up, but the audience assumed that those cables were now in use when NOTHING was changed at all. The original cables were still connected to the speakers.

Naturally all listening were flabbergasted at the improved resolution, the sudden appearance of previously unheard details in the music.

Bias, suggestion and other cues are part and parcel of the human existence. We cannot but help to be influenced by our conclusions.

You gonna tell me someones conclusion that they are not subject to error and have no bias will NOT have an effect on their perceptions or stance on matters?? And that that somehow magically disproves the statement they will be affected??




Sonnie said:


> That would truly be awesome.


As an owner of a respected forum you, with time taken and care to do it would be in a position to garner good results.

It will never change things much tho. We as humans can rarely examine our stance dispassionately. That works both ways...you'll never convince the amp guys by a result, and let's say you found a difference you'd never convince the naysayers.

I find it rare that people are honestly after the truth.


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## Savjac

Very good, there really is not much else to say without sounding argumentative and that was not my purpose. It would appear that a tad less than 50% of the folks that answered the poll believe we really hear a difference between amps and a tad more than 50% believe we cannot really hear a difference between amps.

It seems odd that the tad more than 50% wish to push their beliefs harder than the tad less than 50% albeit some of those like Terry J have done so with style and grace. I am not in any way special, quite the contrary, I just have spent many years listening, and listening and listening. As alluded to earlier, I have not been involved in blind tests, although I have attended countless component swaps during extended listening tests, nor do I know anyone that has. (Personally I mean)

Admittedly I will admit to not being the most logical in the bunch as my thought process tends more toward right brain activities and may explain my findings more than my words. I cannot prove what I have heard and frankly I do not know that proof exists any greater than I can prove my dislike of liver. I can describe what I hear in the same way I can describe how awful liver tastes, but that would not be considered proof in the scientific community. 

Oh and I truly would be up to hearing proof that contradicts my belief, as I said before, this is not life or death and it would give me the chance to learn new things that even this old dog needs on occasion. 

So lets just agree to disagree, I do not wish to disrespect this forum nor those in it by typing anything else that may cause further disruptive dialogue from the ahem....Matrix.


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## Gregr

This has been a very nice discussion and I've felt everybody has been very respectful of thoughts and opinions and most of the discussion has focused on clarifying definitions terms and words used. Certainly sarcasm has not been used as a tool to help clarify meaning. It might be important to refrain from describing personality types or stereotypes since we really are discussing potential differences in amplifiers not people. Please???

Sorry, I was enjoying the healthy discussion. I have some fear of attack now but I'll just add. 

I have a friend who designs and builds speakers for a living. We both like to experiment and talk about electronics and sound especially. People travel from quite a distance to buy one or some of his creations and Rogers opinions are highly regarded. We had come to a relative agreement 20 or so hears ago that the speaker has the greatest impact on sound Roger did not included wiring in any discussion except wiring needed to be adequate. But I was not so quick to agree on that aspect of the sound system. 

I can accept that amps of similar design and with high impedance in and low impedance out, when level matched will sound indistinguishably similar. What happens when I turn up the sound to reference levels??? By reference I mean if a sax were in the room my speaker levels of a sax would match the volume (loudness)of the live sax and all else being proportional (80db approximately). I can't always play that loud but I at least like listening to music loud enough so that background instruments are given enough wattage to sound fully formed and musical (60-70db with 120watts driving). 

But that is a whole new experiment isn't it?? In the case of the former I can see the original post is very probable true. With the latter we may begin to hear some differences I suspect but today I have to say I do not have enough experience with any amp nor speakers to say for sure.


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## terry j

Savjac said:


> Very good, there really is not much else to say without sounding argumentative and that was not my purpose. It would appear that a tad less than 50% of the folks that answered the poll believe we really hear a difference between amps and a tad more than 50% believe we cannot really hear a difference between amps.
> 
> It seems odd that the tad more than 50% wish to push their beliefs harder than the tad less than 50% albeit some of those like Terry J have done so with style and grace. I am not in any way special, quite the contrary, I just have spent many years listening, and listening and listening. As alluded to earlier, I have not been involved in blind tests, although I have attended countless component swaps during extended listening tests, nor do I know anyone that has. (Personally I mean)
> 
> Admittedly I will admit to not being the most logical in the bunch as my thought process tends more toward right brain activities and may explain my findings more than my words. I cannot prove what I have heard and frankly I do not know that proof exists any greater than I can prove my dislike of liver. I can describe what I hear in the same way I can describe how awful liver tastes, but that would not be considered proof in the scientific community.
> 
> Oh and I truly would be up to hearing proof that contradicts my belief, as I said before, this is not life or death and it would give me the chance to learn new things that even this old dog needs on occasion.
> 
> So lets just agree to disagree, I do not wish to disrespect this forum nor those in it by typing anything else that may cause further disruptive dialogue from the ahem....Matrix.


Thankyou for the reasoned response, all too often these things go pear shaped if you know what i mean!

You prob do not even realise it, but you are still having a bob both ways. You say proudly (and seriously, good on you..as I said I think it is rare) that you'd be happy to have your beliefs pushed, esp if it were in sake of learning. 

So as THAT stands, the follow on should be something like.."I must get a tad serious about doing a test like this, nothing that might pass scientific curiosity but maybe I'll just get the wife to swap the leads and not tell me which is which'..you know, just a gentle step in that direction if your stated stance was to be believed.

Instead, we get in the very next sentence...'let's just agree to disagree'.

So which IS it? A genuine desire to learn (based on an admission you know nothing really about the way these tests are done, have never organised nor participated in one, finally agreed that you are just as vulnerable to bias and suggestion as the rest of us) yet then 'let's just disagree' (in other words I have no proof one way or the other but hey I reckon you are wrong yet will not test it).

Sorry if it looks like I picking on you, not really. But you are bringing up good points to respond to!!

As an example, you got a bit huffy when I pushed the point that you, and people like you, actually know extremely little about how much we can be affected by bias and suggestion (not even that we can be affected, but by how much. Eg, "ok I accept we have biases, but I don't accept that I would start hearing things I have never heard before simply based on suggestion"...is there a bit of truth in that for you??? Anways, when I say 'you people have no idea'' that is the area I am heading towards..because you CAN hear all these marvellous things you have never heard before, even if like dunlavy no cable was changed at all. It is simply stunning what we can 'hear or not hear' solely due to our beliefs. Ask ANY pro audio engineer about the silent channel, it does nothing yet allows the band member to tweak any aspect of the sound to his satisfaction. And he does. He hears the change and is now happy yet it was never connected in the first place. The mind is a fascinating animal)

hmm, that got a bit off track, sorry. But we were talking about good points of yours to address. Earlier you said dbt's and our minds don't work that way. 'We need time to adjust and hear it, we don't marry someone on the basis of a blind date'

The first and obvious rebuttal is that no where in a dbt is mention of a time limit. You can, if you wish, take a month before you switch. Still, I am not interested in that road but rather the following.

This fatal flaw you mention of dbt's and how long we need to live with a component, can you link me to a post of yours where you explained that you chose your amp after needing a month to get a handle on it? Can I ask you straight up, what worth do YOU put on an amp such that it takes a month before you are comfortable with it sounding different from the one it will replace?

Personally, I would not spend ten bucks if it took a month to hear the differences. Yet that is a flaw of dbts?

One point you have yet to address is quick switching (NOT to be confused with short term listening btw). The ability to instantly switch from one amp (cable etc) to the other without delay, withing the same musical passage and space. That feature is quite often found in dbts (ironically giving the person a greater chance of success than the usual couple of minutes delay used by the golden ears) simply due to the difficulty of organising that. Well, organising a rigorous dbt is such a hassle may as well take that little bit extra to include instant switching too.

Do YOU think that being able to swap between amps within a second is more or less sensitive than stopping, getting up and re-wiring, then sitting back down and re pressing play?

I hope you can at least see that these dbts are not as clearly 'bad' as you previously expressed, and indeed that in many ways they far far exceed the usual audiophile audition process by an order of magnitude.








Gregr said:


> I can't always play that loud but I at least like listening to music loud enough so that background instruments are given enough wattage to sound fully formed and musical (60-70db with 120watts driving).
> 
> But that is a whole new experiment isn't it?? In the case of the former I can see the original post is very probable true. With the latter we may begin to hear some differences I suspect but today I have to say I do not have enough experience with any amp nor speakers to say for sure.


Well, what conclusion would you draw from that instance then?Per the argument going on at the moment, we have an inadequate (ie not enough power) cheap amp that 'fails' at high volumes bested by an expensive audiophile amp (just cause that is how these arguments go ok??:nerd

Would your conclusion be 'Oh, there ya go you naysayers, we do need expensive audiophile amps after all' or 'huh, maybe the bigger brother (or the brother after him if needed) of that cheap amp which matched the expensive name brand all the way till it simply ran out of puff) is all I need".

WHY are these 'a-ha gotchas' always organised that way? That the expensive amp can out match the cheap on at high volumes, thereby justifying the excesses of the audiophile world that way?

Why not ever go the other (_far more likely_) road that the horrendously expensive flea watt powered valve amp (that will basically clip on almost any speaker out there) vs the high powered pro amp that will never run out of puff?

Because it does not suit the purpose and simply shows that the ONLY thing here is to try and find justifications for their stance. As I said earlier, very very few people are _genuinely _curious.


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## Savjac

I do remember Dunlavy quite well but did not know about the cable issue. Interesting.
You bring up a ton of points for which I would like to enter into further discussion. However, I think right now I will be attending Saturday Night at the Movies at the Jack house for tonight's showing of the new Total Recall. Now this may be a bias, but I am not so much looking forward to this disc even though it got some high marks. Never the less, I just have to experience it at least once, and will attend to further discussion tomorrow. 

You know you are right in that some of my thoughts just do not express well here, it seems too many years of writing short, sweet legalese has taken its toll on smooth well thought out phrases. After reading my post I do seem to skip about a bit. Will have to work on that.

To be continued....


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## Gregr

Terry J. you begin with a description of an argument or at least you used the word. I have no interest in an argument of any description. The first 5 pages of this thread have been very interesting as an unbiased exploration of sound amps and personal experience. I felt Savac (Jack) was doing a great job of describing my experience. I've had purchases where I felt I had made a good move and others I questioned in the beginning but learned to love. I would attribute the learning to love with the concept of "Set Point". Whereas as your ability to hear (smell taste or any of the senses) changes and if your intent is to hear music you will negate sound characteristics that get in the way of you hearing music in the sound you are given. 

Some complain every time the system is turned on the sound system takes time to warm up (so to speak) before reaching the systems full musical potential. I believe some of this warming is the mind readjusting to hear the systems full musical potential through any "slight" discordant sounds. 

I am having a very difficult time understanding this recent dialog so I'm going to sigh off.

I will agree to disagree, until I have more info about what just happened.


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## terry j

Savjac said:


> I do remember Dunlavy quite well but did not know about the cable issue. Interesting.
> You bring up a ton of points for which I would like to enter into further discussion. However, I think right now I will be attending Saturday Night at the Movies at the Jack house for tonight's showing of the new Total Recall. Now this may be a bias, but I am not so much looking forward to this disc even though it got some high marks. Never the less, I just have to experience it at least once, and will attend to further discussion tomorrow.
> 
> You know you are right in that some of my thoughts just do not express well here, it seems too many years of writing short, sweet legalese has taken its toll on smooth well thought out phrases. After reading my post I do seem to skip about a bit. Will have to work on that.
> 
> To be continued....


hi Jack (got your name from greg!) (I might not directly respond to yours greg, but some of these might touch on your points?? in any case, don't bow out, how is that in keeping with wanting to learn???:dontknow

I did a very quick search for john dunlavys comments, I did not find exactly (what I thought) I was referring to so maybe over the years I added a bit in my mind (?) but anyway, this gives the gist of his thoughts on cables

http://www.verber.com/mark/ce/cables.html

He at least makes the main point of mine that the audiophiles made flowery descriptions of the improvements when _nothing at all_ was changed. (that at least allows me to apply it to amps).

I think this is where most of the disbelief comes from, 'yeah I get we can be influenced, but to THAT degree? So much we can start hearing things???' The disconnected channel on the mixing desk is a well known classic example of that as mentioned in my last post. Kind of an insiders joke to those guys, works every time.

So to me that is the biggest stumbling block, the complete unreality of how much we can fool ourselves so to speak. And, until someone takes the time and effort to give this a go they will never comprehend it, and why I so easily dismiss their rigid adamant position that what they heard was down to _pure sonic differences_ and *nothing* else.

You simply do not and never will know that till you do the test.

It is not so much your inability to express yourself at all, but you do (perhaps instinctively) simply bring up all the tired old objections *we* have heard a thousand times before, that's all. Some of them just do not stand up to inspection...'well blind tests are worthless because we need time to hear these differences' yet whenever they audition at home these differences are usually jaw dropping, so much so that my wife (who is not interested in audio) heard them from the kitchen whilst cooking the evening meal.

So why then the need to point out it takes a month or so to hear differences? nOPE, SMACKS of an ad hoc construction or objection, that's all.

Let me ask directly, accepting as I do how confident you are of the reality of those differences, why would those differences disappear simply because you don't know which was which? (if that is what happens)

Or alternatively, what worth are those differences if they only appear when you know which is which?

That is what is laid out here, think of it as a possibility only. And like any proposition, it can only be shown to be true or untrue if it is actually tested, not simply theorised about. You might do a properly conducted blind test and ace it, if so then well and good. Not only have you then done the test as laid out, you are also able to reject that hypothesis.

The point is it needs to be done, not just blindly rejected with nothing to back it up other than blind confidence.

For what it is worth, I'll tell you why I kinda made that first post I did (that it's all well and good to make blind statements but they have little worth without evidence/experience to back it up).

On another forum recently someone made the comment that earle geddes feels all that is needed to design a good speaker is to use measurements. In other words, he feels that once you know what is important or not then all you need to do is ensure the speaker does those things and does not do what is bad to do.

Gee, tortured language there but I hope it is clear enough.

Ok, of course all the audiophiles rejected that immediately. Man, you start to pull your hair out ya know??

How many speakers have YOU designed mate? Of course, none. All he does is buy gear and swap them, this cable or that interconnects, these little cable lifters, the list goes on.

I mean, what earthly basis has THAT guy got to reject earles belief?? Man, he has not ever even used REW to measure his system, let alone has enough knowledge data or experience to even have a leg to stand on to begin to dispute the hypothesis.

I mean, that audiophile could be completely right, but he has no idea or experience to show that...so if he is right then it is nothing more that pure luck that makes him right.

Same deal here, the hypothesis is that if sighted we are liable to from erronous conclusions. You cannot falsify that if you never test the non sighted to see if it is true or not.

I got zero problems with people hearing differences, just do not (without testing the hypothesis) simply reject it as being untrue. You have no idea if it is true or not because you have not tested it. (again, the you there being 'everybody' or whatever)

As an aside, I have set up and run dbt's, so I am here to tell you that to do it properly is not a walk in the park, it is not a simple afternoons rig up. To do it properly takes a commitment (why bother ruining it by carelessness?).

All that means is that the urge from *our* side to do a dbt from those who have no idea how much work is involved is equally a little misleading. Both sides of this eternal argument often behave in less than ideal ways.

Take this or leave this, but one thing I have noticed is that those who get involved in the minutiae of audio often don't see the forest from the trees. You guys on this forum _at least_ (I assume) have and do use rew and have at least got an idea of how your system measures, so in many ways even tho we are having this 'argument' you are light years ahead of the truly subjective guys. Those dudes actually* reject* measurements of any description, it is a way of life, belief and mantra for them. Measurements have no use at all and you must simply trust your ears.

So these guys who are into caps, different resistor brands et al (and of course cables and amps natch) truly have no reference point other than 'what they are used to'. That's ok as far as it goes, personal listening pleasure and all that jazz......but boy when an outsider who has not gone down their rabbit hole of tweaking the minutiae hears their system 'cold'.....you kinda shake your head a bit ya know?

I know that can never be a universal experience, but common enough in mine. They are chasing down these absolutely tiny effects that loom large in their own minds (ALL completely sighted and carrying this huge bundle of expectations and god knows what else along with it).....and you hear the system and go Unbelievable!?

It is usually so idiosyncratic by that stage that except to that tiny group it has no reality for anyone outside of it. They simply lost their way chasing these tiny effects (that are tiny, even in principle) yet doing it sighted and hearing all these ear opening moments they have forgotten even the basics of 'let's at least get rid of these twenty db peaks' and such. They do not even know those peaks are there and they reject that there is any worth in finding and fixing them.

Just one example of many of how easy it is to get lost in these detours, and completely rejecting the mere though of ''well, have you ever tried this mod objectively? You know, get your wife to switch it in and out and not tell you?"

No, they are immune from bias and their ears are the most exquisite measuring device in the known universe and science does not know everything and measurements are useless.

That's my little rant for the day haha, thanks for letting me tell it!


So yeah, it's all well and good to have a belief, but at least have the intellectual honesty to KNOW it is a belief.


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## AudiocRaver

First, a personal, sincere note of appreciation to all that we can discuss this extremely fun topic with such passion and continue being nice to each other! Big smiles! Only at Home Theater Shack!

One point that shows up time and again is the value in being able to take time to listen, time for a change to settle in and be recognized. It is true, I believe, that extended listening time is important in helping us learn how to listen and what to listen for. We all are better listeners now than we were five years ago, 10 years ago, maybe a week ago. Our listening brain is a muscle constantly being fine tuned and refined, and the aha moment that occurs in a certain passage of music two hours into a listening session is no less important than the aha moment when switching between speakers in a showroom, or when switching from amplifier a to amplifier b in a DBT. Contrasts, or lack thereof, tell us a great deal, but they rely upon the time in between. How long? A few seconds, minutes, an hour? The listening brain has different time constants at work, and the nature of those time constants may be different for different listeners. Perhaps one listener is more accurate in a DBT with 20 second segments between switches, another with 2 min., another with an hour. Plus, some listeners may get better after the first few A-B switches, so maybe you throw out the first four tests and see how the next 10 go?

Is there any validity in customizing a DBT to the listener's preferences, give the listener the best chance of success, including comfort, relaxation, a glass of wine, the presence of supportive friends, but still with true DBT rigor - versus setting them up to fail? How well would you expect anyone to do when under the gun, in a semi-hostile test environment where she/he knows the testers would like them to fail? While I understand quite well the principles behind DBT, I am not a student of the nuances and details that have been found to work best. What do the experts say about this?


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## Savjac

What a large amount of information has been presented since I retired to the theater last night. Interesting.


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## terry j

AudiocRaver said:


> First, a personal, sincere note of appreciation to all that we can discuss this extremely fun topic with such passion and continue being nice to each other! Big smiles! Only at Home Theater Shack!
> 
> Is there any validity in customizing a DBT to the listener's preferences, give the listener the best chance of success, including comfort, relaxation, a glass of wine, the presence of supportive friends, but still with true DBT rigor - versus setting them up to fail? How well would you expect anyone to do when under the gun, in a semi-hostile test environment where she/he knows the testers would like them to fail? While I understand quite well the principles behind DBT, I am not a student of the nuances and details that have been found to work best. What do the experts say about this?


In a real world, yes to all of your points. AFAICS, if we (all of us) are honest about being honest, then everything possible should be done to maximise the chance of success. Just a few off the top of me 'ead, ideally any test should be done (for example) on the persons own system. After all, that is the one that they are not only most familiar with, but also (in most cases) the only system they are making claims for. It is not much use really to throw them into a completely new environment with completely new gear is it.

Also as yet another example, it should be limited to the exact amps that person claims to be able to tell apart...again not much use really in throwing an amp at them they have never heard and make no particular claims for. Unless of course they are claiming all amps on all systems are different...a claim I have not seen made here.

In all cases the methodology and procedure should be completely familiar to them, take as long as needed to become acquainted with it.

The choice of music should be the testees, and they are completely free to choose the 'killer' section of any track. They have the choice of when to switch, they also have the choice of how to switch (some might be happy with a switch inserted to allow instant switching, others may wish to manually swap ICs and speaker cables)

Once they are familiar with how it is run (that takes as long as it takes) they can listen for as short a time or as long a time as they want, there should not be any restrictions there. Usually it is done sighted first and only when they are confident does it move on to the blinded part. There is no point in going on to the blind portion until and unless the person is certain they can tell a difference.

Having said that, I am equally sure you can see how limiting that is as well, bit of a double edged sword I am afraid.

It is understandable that some may feel that the tester 'wants them to fail' when viewed solely from forum posturing. It often devolves to that in many arguments, but on the whole when finally face to face it does not turn out that way, at least in my experience. (truly, these differences or antagonisms fade away face to face...the curiosity and interest remains however)

But, as always, it comes back to a genuine desire to learn, and that desire needs to come from BOTH sides of the fence. (just as an aside, that is why it needs to be a true dbt...if it is then the tester _as well_ as the testee have no idea of which is which. IF it is true that the tester 'wants' them to fail, at least they are not in a position to influence the outcome...see that it is fair to both sides in that regard???)


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## JerryLove

The other thing is that there are a lot of DBTs.

Harmon Kardon, for example, does DBTs for speakers (they also did them for cables and the like); and in the speaker DBTs there are differences found and there are consistent preferences produced. 

Why is it that DBTs work for finding differences in speakers but not in level-matched amps?

DBTs also work in foods, scents, and any number of other things.


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## Savjac

JerryLove said:


> The other thing is that there are a lot of DBTs.
> 
> Harmon Kardon, for example, does DBTs for speakers (they also did them for cables and the like); and in the speaker DBTs there are differences found and there are consistent preferences produced.
> 
> Why is it that DBTs work for finding differences in speakers but not in level-matched amps?
> 
> DBTs also work in foods, scents, and any number of other things.


This is a good question but I personally do not think they always work well. The folks being tested are not comfortable and I am sure they feel they HAVE to perform or they fail. Second, imo, in what other like of products does the items in question have to be manipulated between the source and the end of the line, in this case being the speaker. Level matched, make sure they are operated only within their limitations and so on. This just does not seem natural to me. In doing a truck comparison, would it be proper to lower the horsepower of my Tundra to that of the basic Silvarado so that they are both the same and nothing has an advantage. That would be silly beyond belief as I would have no idea how either vehicle operated in the real world. A DBT of the vehicles would have them both matched in HP, weight, speed, and quality of components, warranty and many other things. Do we do the same for blenders, both operate on 120 volt system but because one is more powerful we cut back the amount of power to it so it operates with the same crunching abilities as the lesser unit ? No that would not be good either. 

In sports should we use a DBT for the athletes and only test them in perfect weather on a perfect sunny day with no other players or audience ? I mean that is when the athlete is really tested is on the field doing what they do in front of millions of viewers....no pressure there. 

There really is nothing I can say that would convince those that truly believe in the DBT test that maybe it is not perfect and until I am proven wrong I will believe I can hear some differences in equipment. I guess that is about all I have as it has already moved into way too many subjects already.


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## primetimeguy

Savjac said:


> This is a good question but I personally do not think they always work well. The folks being tested are not comfortable and I am sure they feel they HAVE to perform or they fail. Second, imo, in what other like of products does the items in question have to be manipulated between the source and the end of the line, in this case being the speaker. Level matched, make sure they are operated only within their limitations and so on. This just does not seem natural to me.


Then by your standards your amp/receiver sounds different everyday since you listen at different volumes. 

If you were comparing color reproduction on a TV would it be fair to turn up the color to max on one TV and minimum on the other and reach a meaningful conclusion?

The point of a DBT test, or almost any test for that matter, is to hold everything but the test variable constant. If you do not do that you don't know if any difference is because of the test variable or the other variables changing.


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## JerryLove

Savjac said:


> This is a good question but I personally do not think they always work well. The folks being tested are not comfortable and I am sure they feel they HAVE to perform or they fail. Second, imo, in what other like of products does the items in question have to be manipulated between the source and the end of the line, in this case being the speaker.


You've lost me. Amp comparisons are done on one pair of speakers (though you could use two identical pairs if you lacked the proper switching gear)



> Level matched, make sure they are operated only within their limitations and so on. This just does not seem natural to me.


What is unnatural? Listening to music at some arbitrary volume or not asking 100w amps to power 1000w speakers at full volume.



> In doing a truck comparison


Analogies work for a while but eventually fail... like trucks.

You'd do better to compare truck batteries. Once you pass a threshold, the extra power available from the battery becomes irrelevant and all batteries will perform the same. (yes: we can talk about durability or the like; but we can do that in amps too.. and we aren't; we are talking about sound).

Then move all those identically performing batteries to a truck with a higher crank-amp requirement (maybe from an S4 to a V8). Suddenly, the lowest powered ones stop performing properly. That doesn't mean that there was a difference in performance on the S4, just that there is on the V8. Even then: the batteries will fall into two classes: powerful enough (which will all perform identically) and not powerful enough.

Like amps. 



> A DBT of the vehicles would have them both matched in HP, weight, speed, and quality of components, warranty and many other things. Do we do the same for blenders, both operate on 120 volt system but because one is more powerful we cut back the amount of power to it so it operates with the same crunching abilities as the lesser unit ?


That's not actually how any DBTs are done. You are hacking at a straw man. No one lowers the power on an amp: we just set them to the same volume... like comparing two cars highway performance by driving them both at 70mph on a highway. 



> There really is nothing I can say that would convince those that truly believe in the DBT test that maybe it is not perfect and until I am proven wrong I will believe I can hear some differences in equipment.


If you are playing the two different pieces of equipment at different volumes you most certainly can hear a difference. One is louder.

If you are playing one within its performance range and demanding more than the second can deliver: you most certainly are hearing a difference. You are hearing clipping, distortion, and uneven frequency response.

Otherwise it's imagined.


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## J&D

Very interesting argument regarding making the test subject comfortable as I had not thought about that. In the testing scenario's I participated in there was no lack of confidence on the part of the participants. Maybe the audiophiles I met in those days were unique in that they were confident to a fault. They were absolutely certain they could hear differences in amplifiers. Even those they had little familiarity with because they were convinced that the superior design, quality and care taken in creating the product would so greatly overshadow the so-called inferior product. Sure, there were arguments afterword that the test must have been flawed in some way but being comfortable and familiar with the test subjects was not a complaint. 

Now, I can see why you might think a glass of wine, some soft lighting and an easy chair might help in making the subject more comfortable and subsequently hear better but my money would still be placed on the side of no change in the outcome. There are no perfect test methodologies but DBT's are the best we have in the audio world. 

I would also like to add that although I pushed to have my particular amp DBT tested against some big dogs it was not my intent at all to have the test conducted in a manner that would insure my amp won. In fact, this test did not prove my amp was superior in any way - there were no winners or losers. The only outcome of this was that none of the participants could discern any sonic differences between the amps.

JD


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## Savjac

Yeah I kind of new this would happen. Change trucks to batteries then we should change amps to capacitors.

There is no strawman as there is no fallacy. The information about the DBT test indicates the amps cannot compete against one another without having some controls introduced thereby making them more equal on various levels.

This is like discussing religion or politics, each participant has their beliefs and those beliefs are unlikely to be changed by any rhetoric. Thanks for the exchange, its just too frustrating for all parties so it is time to go listen to things I cannot hear. Should be interesting.


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## JerryLove

Savjac said:


> Yeah I kind of new this would happen. Change trucks to batteries then we should change amps to capacitors.


Again: analogies get you so far, but eventually fail.

Change batteries to trucks and we should change amps to "systems including room treatments".

But of course the truth of analogies is in their utility. The comparison is inept: therefore a bad analogy.



> There is no strawman as there is no fallacy.


That sentence doesn't actually make sense in English.

"Do we do the same for blenders, both operate on 120 volt system but because one is more powerful we cut back the amount of power to it so it operates with the same crunching abilities as the lesser unit ?"

Let's try that 

"Do we do the same for aplifiers, both operate on 120 volt system but because one is more powerful we cut back the amount of power to it so it operates with the same crunching abilities as the lesser unit ?"

We don't lower the power on amps in DBTs. We adjust the gain on either the amp or the pre-amp to match volumes. If we did not: then you would always hear a difference. One would be louder than the other.



> The information about the DBT test indicates the amps cannot compete against one another without having some controls introduced thereby making them more equal on various levels.


In this case you are arguing against amps being identical under all circumstances. But no one has claimed that amps are identical under all circumstances. This is therefore another straw-man argument.



> This is like discussing religion or politics, each participant has their beliefs and those beliefs are unlikely to be changed by any rhetoric.


Yes. Except that in this case it's a heavily tested science which is used throughout almost every industry in existence in order to create more appealing products. Another bad analogy


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## Savjac

Well there you have it, it is obvious we remain happy in our beliefs to which few of us will find occasion to change.


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## Sonnie

As stated earlier... a man's opinion changed against his will is of the same opinion still.

The biggest difference in the two sides right now is that those who say that they cannot hear a difference have objective proof to back up their claims, while those that claim they can hear a difference have yet to provide any objective proof... and ironically some of those are not willing to subject themselves to objective testing that would prove otherwise. That is pretty convenient.


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## chashint

Savjac, how would you feel about a $200 AVR being declared sonically superior to any system you care to specify simply because its output volume was set 1.5dB higher in a blind test (notice I said blind not double blind) because that is exactly what would happen.
Same thing would happen in double blind but it is nothing to quibble over.

I don't think anyone here is opposed to owning and enjoying 'high end' electronics or even 'high end' cables.
Where the objections come from is in response to the pseudo science the audiophile community and manufacturers push as truth.
In the past it may have been possible to discern differences in electronics, but now all of the components are commodity items and the tools available to electrical engineers allow designs where variations are measured to the third or forth digit.
There is nothing magical about electronic circuits, what is factual is audio circuits are very simple comparatively speaking and the component values necessary to alter audio frequencies is very large so it is actually pretty hard to screw it up.


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## Gregr

Hello all,


Getting back to the original post, it is important and I believe customary to accommodate the challenger to the highest degree possible. In this instance there can be no denying the outcome and the assigning of a high degree of validity to the statement of two similar amps being indistinguishable from one another when played within specific parameters. I would think the Zipser challenge clearly proves the point of the original premise in that Zipser was given ample opportunity. This is a clear benefit of accommodating the challenger while maintaining the parameters of the original study question. To clarify here is the original statement … 


“If amplifiers A and B both have flat frequency response, low noise floor, reasonably low distortion, high input impedance, low output impedance, and are not clipped, they will be indistinguishable in sound at matched levels no matter what’s inside them. Of course, some of the new “alphabet soup” topologies do not necessarily satisfy those conditions.”

Read more: Can we really hear a difference between amps? - Home Theater Forum and Systems - HomeTheaterShack.com 

I can accept this…, I am confident Zipser was provided every opportunity to do his best to prove his point. I believe the outcome of the Zipser study clearly demonstrates the original statement is True and that the Zipser claim to hear a difference is in fact false. But in our discussion I sense certain assumptions have been added to the meaning of the result described above. 



In any case if we were to perform a statistical analysis of the Zipser study I am confident we will find the original study question is a question with a high degree of validity. With regard to the result I believe any statistician will ask for more testing. The testing should include a broader base of amplifiers and a greater number of participants and probably a greater number of trials. As I said I am confident this study strongly indicates the original statement is true to a relatively high degree but with greater numbers of people and amps included in testing and with the same result it would then be completely ethical to make a statement that will read - amps of similar design when played at equal levels will always sound indistinguishable from one another.


…but I wonder about higher volume levels. 


I wonder also, if claims have been made a thousand times…, well, maybe there is some (more than one) real truth in that mix of ideas. Typically I find there is not much truth in all or nothing thinking. In my 60++ years I do not believe I have ever found where any one belief or bit of knowledge or experience is the single authority on any subject. This is true for science and technology as well as religion and politics and human behavior as well. 


The quotes I’ve read are simply one added opinion. Granted the people quoted have years of experience but when it comes to opinion it is simply one more. It is the study result that says it all and what is that saying...


A few additional thoughts…, I think Zipser was shocked to see the result and the 4:10 was telling but the 6:10 result was less telling. In fact the 6:10 could indicate there is some distinguishable difference between the two amps. I am not sure what a random result would be. I do know this I am completely enjoying my search and my own experiments. I do believe my cheap Denon amp sounds pretty good in general. I do believe the Zipser study shows that is true. I believe I’ve also seen a cumulative improvement in sound stage and musicality as a result of changes to the system over the years and speakers being the greatest improvement.


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## lcaillo

I have removed six posts. The thread is becoming too contentious and personal. We will only continue this discussion if it can be done in a respectful manner. Some of the posts were clearly hastily written and nearly unintelligible. The forum rules require that we articulate ideas with good grammar and without demeaning, snarky, or sarcastic comments about or to others. 

Everyone has a bias, and all of the perspectives here are opinion. Some can be backed up with more objective support than others, but everyone is due the right to express their experience. Experience is not objective, and it may not even represent another persons version of reality, but we can still discuss that experience and perception with respect and try better to understand what drives it. 

This forum is about sharing ideas and experience in a respectful and considerate manner.


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## Savjac

I am sorry for causing any issues and will refrain from further posting.


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## lcaillo

Let me be clear. We encourage all users to share their views. If one creates problems and demonstrates repeated disregard for the rules and vision of the forum, they will be removed as users here. Everyone who is user here is capable of civil discourse. Redirecting a thread is not intended to be a message to any one user to not post in the thread. If we have a personal message to send to a user who demonstrates intransigence, it will not be done in the forum. This is a case of several users departing from the forum vision of sharing knowledge and experience in a respectful manner.


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## Gregr

My apologies to all!!! For my part in disrupting this very interesting discussion I am truly sorry. My big brother routine kicks in unexpectedly at times. I could have said something earlier like a PM to the Mod 

I have no lingering anger or animosity toward any one in this thread. If anyone of you believe there could be a benefit in continuing this discussion..., I'd really like to hear more.


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## Gregr

Hope all of you at HTS have a truly Grand Christmas, Hanukkah, Kwanzaa, or Three Kings Day and who can forget the National Whiners Day tomorrow (NWD). Honest to goodness a NWD.

Seriously though, Happy Holidays All"


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## Savjac

And to you Gregr, Happiest of Holidays, although I truly have never heard of the NWD. 
Looks like Santa is going to bring us plenty of snow and other goodies this evening. Yay.


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## Gregr

I am speaking the truth. I googled "Holidays and Celebrations in December" and "Ask.About" came up with a long list and on the 26th was (NWD) National Whiners Day - I thought to point this out only because I got a long devilish grin when I noticed it. LOL
Not really..., I did get a chuckle and I hope you all did as well. 

I hope you are all enjoying your time off with family and friends.


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## Savjac

I do believe you, and it appears today is the day. Lucking I am socked in by a blizzard and cant get out to hear them :T


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## informel

Gregr said:


> Hello all,
> 
> A few additional thoughts…, I think Zipser was shocked to see the result and the 4:10 was telling but the 6:10 result was less telling. In fact the 6:10 could indicate there is some distinguishable difference between the two amps. I am not sure what a random result would be. .


To me this is exactly what happened a random result, if you flip a coin you would average 5:10, if you do the test over and over you may even get 8:10 or 2:10.

If there is an audible differnce then he should get 10:10, if he gets 8 or 9 out of 10 consistently, then I would say there is something very sutile.


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## Sonnie

Good points! And I am not sure subtle differences would cause me to pay a lot more for an amp. Something else will have to cause me to spend more... cosmetics or color maybe. A totally noticeable improvement in sound would be a consideration for me to spend more, but if it is that much different, why... and are there others that sound like it that I should be considering?


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## Gregr

You're right Sonnie those are big biases. 
Or I'd like the name KRELL emblazoned at the very center and bottom of the 1/4 plate Aluminum face.

However if you compile the two test results you get a perfect mean score of 5 out of 10 which is a nice indicator of "the best Zipser could do was just guess". 

So then "What is it?" What makes mature intelligent experienced individuals believe the sound they have is improved over what they had??? Why do we believe we hear better sound from other select equipment. Why..., beyond the "we hear what we want to" philosophy. I am not saying that is not true. I am saying I'm sure it is more complex otherwise we would all see this and agree.

I see I can overlook certain sound charectoristics in order to hear the better sound underneath and after awhile I can get pretty good at hearing just the good music over the wrest. But then that cymbal hiss disappears in the next track. So recording quality is huge. But I have days that nothing sounds right. Then sometimes with a software driver EQ I increase LFE and I've got it. Then the next day its something entirely different. Then some days its all simply magic. 

I can accept how I feel has an impact, that's an easy one as well. 

I have my digital cable out of the system for repair. I do not like fiber optic and that is what I am using. I have many days I do not like this cable..., I know that because I will listen to music for no more than 2 or 3 cuts before getting bored. But its great for movies. 

I am going to wait for a day when I believe music sounds nice through the fiber optic cable. Its possible I've almost been there a couple of times. But in addition I want to believe the digital cable is just another cable and up to a point I do but I can't explain the impact it had on me when I plugged it into the system for the first time. I know changes are almost always a nice thing

Changes are always refreshing because of all the little compromises we make that make us weary so the change can be relaxing and refreshing. 

Well one day I will reintroduce this cable with the expectation of little change other than a refreshing change. I am interested to hear "No difference"


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## JerryLove

OTOH: I paid to buy new couches that matched my decor. I bought paintings and pictures for my walls. It seems I will pay something for aesthetics. Those McIntosh's are pretty...


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## informel

Gregr said:


> You're right Sonnie those are big biases.
> Or I'd like the name KRELL emblazoned at the very center and bottom of the 1/4 plate Aluminum face.


If you can afford it, why not, for the same reason peoples buy Porche, Ferrari, Lamborgini, they all go past the speed limit but are much sexier than a min van.



Gregr said:


> So then "What is it?" What makes mature intelligent experienced individuals believe the sound they have is improved over what they had??? Why do we believe we hear better sound from other select equipment. Why...,


If I had the money to buy McIntosch, I would just buy it, I would not audition a ton of receivers, they have a good reputation and this is good enough for me.
An analogy for that would be a young guy who modify his Honda Civic to a point where he can beat a Porche on a race track, for him his car is better because it is faster, but the owner of the Porche will tell him that his car handle better and both are right but if I had the money I would go for a Porche even if maximum speed is 55MPH. An expensive amp might sound the same as a cheaper one, but if you try to drive something like Magnepan speakers you will see that the better amp as better "handling"




Gregr said:


> I have my digital cable out of the system for repair. I do not like fiber optic and that is what I am using. I have many days I do not like this cable..., I know that because I will listen to music for no more than 2 or 3 cuts before getting bored. But its great for movies.


I felt the same thing about CD when they came out, sound was great but I felt the music was lifeless, something was missing, probably the noise


----------



## chashint

If you truly are able to hear a difference in music between a 'digital' cable and an optical cable there is a problem in your source or processor.
If you think you can hear a difference between different 'digital' cables or optical cables the 'problem' is in your head.
When the conversation is about amplifiers there is at least amplification taking place.
When the conversation moves to cables the 'science' that is oft misquoted, completely ignores the electrical wavelength of audio frequencies which render transmission line theory irrelevant and in the case of 'digital' cables the speed of the data transfer does not even warrant a bit error test. 

Having said that I think it would be great to have all McIntosh electronics ( insert your dream brand) because I really like the cachet and cosmetics plus they are well built pieces of equipment.
Along the same vein since that kind of electronics would mostly be to impress myself I would connect it with fancy looking cables. Not because I think they would be sonically superior but just because I would want to look at it and think wow that looks great. 
Does high end electronics and wires sound great ? .... Of course.
Does it sound better than mid grade electronics and $2 interconnects ? .... Electrical engineering and double blind tests do not support that opinion.


----------



## Dub King

The events of the past few days have me saying 'Yes' without question some amps have a more refined sound than others. I just acquired a Pioneer Elite SC-55 receiver and was switching my mains from the receiver's amps to a Crown XTi-1000. There is no question the receiver's amps are more refined. Despite the significant difference in RMS output, I've given up on using the Crown as an outboard amp for the mains. The whole soundfield becomes less lush, less 3-dimensional. High notes lost their refined smoothness, some 'S' sounds became too harsh for my taste.


----------



## Savjac

Welcome to the difference side Mark . There are so many wonderful and yet frustrating things waiting for you out here.


----------



## Savjac

chashint said:


> If you truly are able to hear a difference in music between a 'digital' cable and an optical cable there is a problem in your source or processor.
> If you think you can hear a difference between different 'digital' cables or optical cables the 'problem' is in your head.


A bit of a tough stance here and maybe a bit forward unless someone has heard all the available cables and combinations out there....and please note, I think that the difference in cables is very small indeed...but apparent on occasion. I was recently changing some digital cables and was really surprised when the Monster reference interlink was removed and a newer Blue Jeans cable was put in. I have no clue why there would be a difference if they are both 75 Ohm cables but it was really apparent and repeatable. I wonder if interconnects can suffer the same oxidation problems that speaker cables can. I remember some time ago thinking that my system was slowly becoming boring and so I went to clean my connections and found the original monster cable I used was turning black under the clear dielectric. Swapped em out with some proper copper cable and voila, much better sound. Maybe some of the cables are just not made as well as others and go bad over time.


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## JerryLove

Dub King said:


> The events of the past few days have me saying 'Yes' without question some amps have a more refined sound than others. I just acquired a Pioneer Elite SC-55 receiver and was switching my mains from the receiver's amps to a Crown XTi-1000. There is no question the receiver's amps are more refined. Despite the significant difference in RMS output, I've given up on using the Crown as an outboard amp for the mains. The whole soundfield becomes less lush, less 3-dimensional. High notes lost their refined smoothness, some 'S' sounds became too harsh for my taste.


In your shoes: I'd next coopt a friend or relative to hook one of the two up at random, set a random volume, and see if I could identify (correctly) which amp based on the s-sounds. I'd then repeat it maybe 5 times. If I wasn't 5/5: I'd get confused and plan a more rigorous test.

Of course: depending on your speakers there might be a difference. You may find the failings of the Pioneer pleasant. Many people buy tube amps for the same reason.


----------



## Gregr

Savac 
I'm glad your still here. I thought you might have totally given up on trying to speak your piece here. I still feel you were giving this idea/premise/belief a good honest appraisal. I don't think its as easy as yes or no but I'll be hanged if I understand how this works.

But let me try to explain myself. I know when I've been successful at something important to me..., well, the world is my oyster and I am the 1:1mill pearl. Everything feels right and music is a beautiful invention and my system sounds incredible. However when I feel sick it is the opposite..., nothing feels right. I think the problem is, for me, music is always fluctuating somewhere in between. 

I mean when I'm streaming Pandora some recordings are decent and some are great and some......... well, need work. Then take the constant of the electronics out of the picture, well, then there's me, I am the big variable and I see I do a number on sound/music through my system. For you Mark I think changing out a system is always a good thing but a month from now if you end up listening to your system no more or no less than with the other amp then how much better is it really. Cause the bottom line is you can always DAC EQ the brightness out of the sound. (But I agree with your take on Crown it is a brighter sound)

So first ruling out the obvious and the constants the only variable is how I feel, what I expect, what I'm looking for today in music that I get or is missing because of my awareness or my distraction in reaction to expectation...... 

I will never take part in this survey. I could never be sure if I am listening to my amp and feeling frustrated so the amp sounds bright or muted and I mistake it for the challenger's amp. However if I could turn up the amp to -20db where my AVR typically 
gives the most detail and the details all sound musical and fully formed (if you know what I mean). If we could put the amps through a series of tests I believe I could identify my AVR more than 50/50, but I'll never try.

Setting two very similarly constructed amps to a moderate volume and level matched 
certainly does not allow an amp to show its stuff and the point is amps are pretty much equal to begin with...

I still don't know what the answer is..., but today I'm lovin my music stream with The Band and Eric Clapton's early music with Mayall


----------



## Savjac

Naw Greg I tried but there is a feeling that for once it really does not matter as there really is no right and no wrong, only differences. Science is a good thing but science does not tell us everything we can experience, feel, believe, endure or know. If I had not experienced the joys of listening to music "Through" my system I would not have hung with this hobby so long and through so many changes. If it was just a love of equipment or something of that nature, I could have bypassed a ton of frustration, but would have missed some of the incredible triumphs. 

I do not listen to music as background so much unless I am driving then XM Radio is one of the ways to make the time and miles go by, second only to the great audio book. For some reason listening to music in the house as background has its problems because if something comes on that I like or want to hear, whatever I am doing will stop and I will start to listen. That is just a quirk of mine but a quirk none the less. 

I have a good deal to learn yet, trying to get my ears around digital in way of networked music residing on a hard drive being fed into my DAC and it is in and of its self somewhat frustrating what with all the different options and all. I know all they are all supposed to sound the same in way of different cables, USB vs. Coax Vs. Toslink, Vs. Wireless to the Server on the rack blah blah blah, but there sure are some big difference in my world. 

None the less, for every negative there seems to be a positive, and this is true for reviews as much as it is for beliefs so who knows. I like the differences, whether I am believed or not.


----------



## JerryLove

Gregr said:


> Setting two very similarly constructed amps to a moderate volume and level matched
> certainly does not allow an amp to show its stuff and the point is amps are pretty much equal to begin with...


You can set them to ear-bleeding loud if you like. As long as the amps are not clipping.

If you set them to different volumes, the louder one will always sound better (until it becomes painfully loud, then the other way).

And yes, A 2000W McIntosh MC2KW will sound very different driving a OrbitShifter at max volume than a Sony AVR (since the sony will max out at a fraction of the volume). It will also sound different driving B&W N801's, since the 2-ohm load will fault out the Sony.

But then you go home and want to power your Paradigm Studio 60s to reference (105db) and you discover that, in actual use, the MC2KW sounds identical to (say) the Yamaha P5000S.

With real speakers, say Paradigm Studio 60's, both of those amps, one $600 and the other $30,000 will sound identical well past the point that the speakers have burned out for being over-driven.

Which is the more realistic scenario for your home listening? 139db-constant subwoofer or 105db-peak reference level?


----------



## Dub King

Frankly, I find the idea of wearing someone else's shoes a bit gross. As for your 'test' I can't see what help my neighbor would be; they already hate me for the noise I make. Could you be specific about the 'failings' of my AVR? Is it the .003% THD that's tripping it up? I don't think 'many' people buy tube amps at all, just a tiny little sub-segment of audiophiles. 



JerryLove said:


> In your shoes: I'd next coopt a friend or relative to hook one of the two up at random, set a random volume, and see if I could identify (correctly) which amp based on the s-sounds. I'd then repeat it maybe 5 times. If I wasn't 5/5: I'd get confused and plan a more rigorous test.
> 
> Of course: depending on your speakers there might be a difference. You may find the failings of the Pioneer pleasant. Many people buy tube amps for the same reason.


----------



## JerryLove

Dub King said:


> Frankly, I find the idea of wearing someone else's shoes a bit gross. As for your 'test' I can't see what help my neighbor would be; they already hate me for the noise I make. Could you be specific about the 'failings' of my AVR? Is it the .003% THD that's tripping it up? I don't think 'many' people buy tube amps at all, just a tiny little sub-segment of audiophiles.


 Well: for one thing it would break if asked to sustain signifigant output into a 1ohm or 2ohm load. For another: if you can find the data you may want to compare capacitence between the two amps; which is part of what will affect curret. Speaking of which, the rails on the power-supply are likely to peg at a lower current in the Pioneer than in the Crown.

The Crown might power my N801s at reference... the Pioneer would not (it lacks the wattage and as it's max output approached, the 2-3ohm load would fault it).

I wouldn't worry about the THD. No well-constructed amp I am aware of has one high enough to even hope to hear. The source of signifigant THD is speakers, not amps.

Tens of thousands of tube amps sell every year. I suppose you can define "many" however you like.


----------



## Dub King

I'm not worried about THD. I was being sarcastic ;-) The 'inadequacies' you mention, they are all current-related and have nothing to do with SQ. BTW You have zero proof that N801's would fry a Pioneer Elite receiver. Plenty of evidence people do in fact drive them with Elite. YMMV but I'm not buying your argument... perhaps protection mode gets triggered on a massively punishing passage, but with up to 3,400 watts of Crown power going to my subs, I'm not likely to run into that issue.

I'm well aware of the capabilities of both my Crown amps as well as my AVR. As far as I understood this thread is not about pushing difficult loads at maximum output. The difference you are using full-sized mains and I am not. You are running a difficult load and I am not. The truth is still plain enough to anyone with a good set of ears - the Pioneer's amps sound more refined so long as they are driving a speaker that is properly matched to it. They remind my of the twin Sony TAN-77ES amps I used to own, as far as the sonic character goes.

Tube amps - compared to pro amps and AVRs and solid-state amps, fewer tube amps are sold. Call it 'many' if you please but it is the smallest market segment - the least popular, if you will.

What I will say is that were I lucky enough to own the illustrious 801 but could not afford more amps than I have, I would bi-amp and allow the Pioneer to handle the highs and have the Crown handle the lows. Best of both worlds IMO. I am confident those speakers would reveal differences between the amps, differences that would favor the Pioneer so long as it was not being stressed. It is effectively what I do by implementing front-firing sealed stereo subs on the L/R channels as 'speaker stands' for high-resolution bookshelf speakers. It's a system that 'keeps on giving' - I've crossed over as high as 600 hz. Works like a charm - I have four DIY LLT subs and a pair of sealed. As I'm sure you already know, whatever works and it's all about what pleases you, the listener. I'm not dogmatic, given a chance I'd love to hang out and run experiments. Wish I had the time.



JerryLove said:


> Well: for one thing it would break if asked to sustain signifigant output into a 1ohm or 2ohm load. For another: if you can find the data you may want to compare capacitence between the two amps; which is part of what will affect curret. Speaking of which, the rails on the power-supply are likely to peg at a lower current in the Pioneer than in the Crown.
> 
> The Crown might power my N801s at reference... the Pioneer would not (it lacks the wattage and as it's max output approached, the 2-3ohm load would fault it).
> 
> I wouldn't worry about the THD. No well-constructed amp I am aware of has one high enough to even hope to hear. The source of signifigant THD is speakers, not amps.
> 
> Tens of thousands of tube amps sell every year. I suppose you can define "many" however you like.


----------



## Savjac

"And yes, A 2000W McIntosh MC2KW will sound very different driving a OrbitShifter at max volume than a Sony AVR (since the sony will max out at a fraction of the volume). It will also sound different driving B&W N801's, since the 2-ohm load will fault out the Sony."

This is weird indeed, I doubt that the JRT would tell much of anything in way of how and Amp sounds. I dont think we are going for max power in this forum. I really would hope this kind of speaker is not used in home applications, with that much folding it is to be used outside or the bottom end will never completely work.

I have owned the B&Ws for many years and can say with great confidence that if you pull them out from the walls a bit and sit in the sweet spot between them when auditioning equipment and you cannot hear differences in amps, well then there you have it.


----------



## JerryLove

> I have owned the B&Ws for many years and can say with great confidence that if you pull them out from the walls a bit and sit in the sweet spot between them when auditioning equipment and you cannot hear differences in amps, well then there you have it.


So a 60wpc amp rated for 8ohms is just as capable of producing faithful, 105db @ 4m level sound in a 2ohm 91db speaker (that would be 100w-400w depending on if your room was -3db/doubling or -6db/doubling) as a 2000w 1ohm rated amp?

I must wonder why the manufacturers *don't* say their amps are good with 2 ohm loads when, according to you, they are. It seems their marketing department has failed epicly.


----------



## JerryLove

Dub King said:


> The 'inadequacies' you mention, they are all current-related and have nothing to do with SQ.


Insufficient current doesn't adversely affect sound? You and I have very different understandings of how a voice-coil works. You really don't think that the high capacitive phase angle in the midbass poses a challenge for the amp in a Pioneer AVR?

Since you have a belief system regarding how amps affect sound: please enlighten me as to what causes the sound you hear in your Pioneer vs your Crown. I can read a circuit diagram if you want to use one.



> BTW You have zero proof that N801's would fry a Pioneer Elite receiver. Plenty of evidence people do in fact drive them with Elite. YMMV but I'm not buying your argument... perhaps protection mode gets triggered on a massively punishing passage, but with up to 3,400 watts of Crown power going to my subs, I'm not likely to run into that issue.


I have only Pioneer's claim that it's not rated to drive that speaker. If you want to send me your Elite and escrow some money for any damage to my speakers that may result; I'd be more than happy to hook it up and crank the volume for a couple of hours.



> The difference you are using full-sized mains and I am not. You are running a difficult load and I am not.


I have absolutely no idea what you are driving at. Do you have any idea what I said that you are responding to?

Here's what I said: "Of course: depending on your speakers there might be a difference."



> The truth is still plain enough to anyone with a good set of ears - the Pioneer's amps sound more refined so long as they are driving a speaker that is properly matched to it. They remind my of the twin Sony TAN-77ES amps I used to own, as far as the sonic character goes.


Then the truth would be plain in a DBX test. How come none of those have every found this difference?



> Tube amps - compared to pro amps and AVRs and solid-state amps, fewer tube amps are sold. Call it 'many' if you please but it is the smallest market segment - the least popular, if you will.


Usually, when there are only two markets, we use the term "smaller", not "smallest". You seem to be employing prejudicial language while arguing semantecs.



> What I will say is that were I lucky enough to own the illustrious 801 but could not afford more amps than I have, I would bi-amp and allow the Pioneer to handle the highs and have the Crown handle the lows. Best of both worlds IMO. I am confident those speakers would reveal differences between the amps, differences that would favor the Pioneer so long as it was not being stressed.


Well. I don't have your Pioneer Elite, and I don't have your Crown.

But I do have a Pioneer 9700 (which was the top of the line in a day when there were no elites), and I do have A Yamaha P5000S, and I do have a McIntosh MC2120, and I do have N801's. And the only time I hear a difference is that I hear problems using the Pioneer (which runs many other speakers here just fine).

In fact: It was the 801S2 that caused me to stop using my Pioneer AVR as my testing amp and purchase the Yammy.

BTW: since you've told me above both that "Plenty of evidence people do in fact drive them with Elite.", and that the Pioneer sounds better: why on Earth would you bi-amp? That seems to fly in the face of your stated position.


----------



## Dub King

Yawn. Your knowledge reigns supreme, I will never argue with you again. Look at the speaker in the icon, realize it sounds better than your B+W and let's call it a day.



JerryLove said:


> Insufficient current doesn't adversely affect sound? You and I have very different understandings of how a voice-coil works. You really don't think that the high capacitive phase angle in the midbass poses a challenge for the amp in a Pioneer AVR?
> 
> Since you have a belief system regarding how amps affect sound: please enlighten me as to what causes the sound you hear in your Pioneer vs your Crown. I can read a circuit diagram if you want to use one.
> 
> 
> 
> I have only Pioneer's claim that it's not rated to drive that speaker. If you want to send me your Elite and escrow some money for any damage to my speakers that may result; I'd be more than happy to hook it up and crank the volume for a couple of hours.
> 
> 
> 
> I have absolutely no idea what you are driving at. Do you have any idea what I said that you are responding to?
> 
> Here's what I said: "Of course: depending on your speakers there might be a difference."
> 
> 
> 
> Then the truth would be plain in a DBX test. How come none of those have every found this difference?
> 
> 
> Usually, when there are only two markets, we use the term "smaller", not "smallest". You seem to be employing prejudicial language while arguing semantecs.
> 
> 
> 
> Well. I don't have your Pioneer Elite, and I don't have your Crown.
> 
> But I do have a Pioneer 9700 (which was the top of the line in a day when there were no elites), and I do have A Yamaha P5000S, and I do have a McIntosh MC2120, and I do have N801's. And the only time I hear a difference is that I hear problems using the Pioneer (which runs many other speakers here just fine).
> 
> In fact: It was the 801S2 that caused me to stop using my Pioneer AVR as my testing amp and purchase the Yammy.
> 
> BTW: since you've told me above both that "Plenty of evidence people do in fact drive them with Elite.", and that the Pioneer sounds better: why on Earth would you bi-amp? That seems to fly in the face of your stated position.


----------



## JerryLove

Dub King said:


> Yawn. Your knowledge reigns supreme, I will never argue with you again. Look at the speaker in the icon, realize it sounds better than your B+W and let's call it a day.


 A flaming-baiting red herring. Impressive... no, the other thing. Pedantic. 

BTW: I'd love to see your spectral decay chart. You've got one, right? No, of course not. That's like asking you to describe your model for what effects sound when you said current didn't do it. I will illicit a response like the above, or an ad hominem, or some other combination of personal commentary / male challenge response / herring... presumably with a healthy does of well poisoning.

~sigh~

Pity.


----------



## Savjac

JerryLove said:


> So a 60wpc amp rated for 8ohms is just as capable of producing faithful, 105db @ 4m level sound in a 2ohm 91db speaker (that would be 100w-400w depending on if your room was -3db/doubling or -6db/doubling) as a 2000w 1ohm rated amp?
> 
> I must wonder why the manufacturers *don't* say their amps are good with 2 ohm loads when, according to you, they are. It seems their marketing department has failed epicly.


Its seems that someone in your head has changed my words, in that I mentioned nothing about 105db at 4m. But I do guarantee that some amps could easily power them, well all can power them but they might not sound like what we would want. But then the amps that failed would easily prove that all amps do not sound the same.

None the less, there is no reason for any of us to be on a crusade to change the other sides mind now is there. Some of us believe there are differences that are audible and some do not. Fair enough but maybe it would be more useful to try to determine why we have such huge differences. The poll seems quite clear that there are overall less people that indicate they can hear the difference, but with the results being so close to 50-50 that is pretty significant. It therefore cannot just be in our heads. There has to be something to both sides....at least that is what the data seems to indicate.


----------



## Dub King

Nope, just a fact. If you can't hear differences between amps, maybe it's your speakers not delivering the goods. Then again, maybe it's your ears? I can hear those 'seagull repellers' they have at shore resorts... can you? Maybe I'm just more sensitive to very high freqs. My speakers pull off the trick - I can hear the difference between amps. I have not heard better sound coming from a 'consumer' speaker no matter how high-end. That's the beauty of DIY and using 'Pro' compression drivers - sky's the limit performance wise, not price-wise. CH horns are brutal , they will reveal the slightest flaw in an amp. I don't know and I don't care why it's the case - although efficiency has a lot to do with it, the same efficiency that allows a 'modest' AVR to push the tweeter while the Crown drives the woofers. I'm just glad for it because I'd hate to have to spend "801 Matrix" money to get good sound from my speakers. I prefer to put my money into my HTPC, that's where the true power resides - music making and editing software. It's nostalgic to think back to the days when the 801's were my 'ideal' with Abbey Road using them as monitors and all that.

Here's another literal fact, B+W products have _never _blown me away. Obviously a matter of taste since they have plenty of fans plus the association with Abbey Road... not to shabby. I've auditioned them every few years to see what's up. I don't know you but it seems like on new years eve you are getting upset over stereos, that's bad news. Good night and happy new year. 



JerryLove said:


> A flaming-baiting red herring. Impressive... no, the other thing. Pedantic.
> 
> BTW: I'd love to see your spectral decay chart. You've got one, right? No, of course not. That's like asking you to describe your model for what effects sound when you said current didn't do it. I will illicit a response like the above, or an ad hominem, or some other combination of personal commentary / male challenge response / herring... presumably with a healthy does of well poisoning.
> 
> ~sigh~
> 
> Pity.


----------



## Gregr

I will add another thought..., it was mentioned in the original Post that Zipser was allowed to use his system wiring intact/as-is for the testing. I don't know what wiring he was using but obviously they did not help. 

The point I'd like to make is..., I found HTS while searching for high copper content wiring. I did not get much help on this here but did eventually find Furutech. I'm not buying their top of the line products but I have found copper wire of highest purity and was introduced to Professor Ohno and Continuous Cast Copper (not extruded but poured copper wire) that is rolled to fine strands as needed. Next they cryogenicly treat the wire while demagnetizing the wire - in effect aligning the electrons while freezing to below -190 (or -390 I'll get back to you if interested) degrees Celsius which tightly compacts the atomic structure and aligns pos/neg charges. These wires are still omni directional and have approx. 7 ohms of resistance per Kilometer and again very low capacitance.

I am not saying these make a huge difference individually but replacing everything beginning with the wall duplex and right out through to the speakers does add up to all of the music shining thru and sounding very musical. I know I'm on the right track when anybody who hears this system for the first time..., inevitably drool on themselves and/or stare in disbelief. All totaled I believe its an improvement and I know the sound is more musical than I have heard anywhere or at anytime. One friend ((a HAM opp and know it all) thought I was crazy and told me to stop wasting my money..., until he heard the result at my half way point. I still use Monster for my 20' surrounds and rears.


----------



## JerryLove

Savjac said:


> But then the amps that failed would easily prove that all amps do not sound the same.


Who said that failing amps sounded the same? I believe that's a group of zero people.



> Fair enough but maybe it would be more useful to try to determine why we have such huge differences. The poll seems quite clear that there are overall less people that indicate they can hear the difference, but with the results being so close to 50-50 that is pretty significant. It therefore cannot just be in our heads.


I don't follow. How does the fact that 50% of respondents believe they hear differences mean that the issue is not psychosomatic?

33% of people have actual physical reactions to placebos. Not just a belief that they hear something, but actual physical effects (http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/placebo-effect)

Magicians count on a near 100% reliability of perceptual bias.


----------



## JerryLove

Dub King said:


> Nope, just a fact. If you can't hear differences between amps, maybe it's your speakers not delivering the goods. Then again, maybe it's your ears? I can hear those 'seagull repellers' they have at shore resorts... can you? Maybe I'm just more sensitive to very high freqs. My speakers pull off the trick - I can hear the difference between amps. I have not heard better sound coming from a 'consumer' speaker no matter how high-end. That's the beauty of DIY and using 'Pro' compression drivers - sky's the limit performance wise, not price-wise. CH horns are brutal , they will reveal the slightest flaw in an amp. I don't know and I don't care why it's the case - although efficiency has a lot to do with it, the same efficiency that allows a 'modest' AVR to push the tweeter while the Crown drives the woofers. I'm just glad for it because I'd hate to have to spend "801" money to get good sound from my speakers.
> 
> Here's another literal fact, B+W products have _never _blown me away. Obviously a matter of taste since they have plenty of fans plus the association with Abbey Road... not to shabby. I've auditioned them every few years to see what's up. I don't know you but it seems like on new years eve you are getting upset over stereos, that's bad news. Good night and happy new year.


Sadly, I got the response I expected. I must carry some blame there as I certainly rose to the bait. Let me try something hopefully more constructive.

I appear to have hurt your feelings somewhere as you seem to be going out of your way to both attack my person and what you presume I am listening to and to repetitively tout your own. I had hoped to discuss the topic, but perhaps we should discuss why you feel the need for such responses? 

FWIW: I'm sorry if I've engendered a negative emotional response. It was not my intent. I'm sure your speakers sound great and am glad you are happy with them.


----------



## primetimeguy

So you replace from the outlet to the speakers, but what about the hundreds of miles of copper prior to your outlet and what about the binding posts on the speakers and their internal wiring?


----------



## Savjac

Gregr said:


> I'm not buying their top of the line products but I have found copper wire of highest purity and was introduced to Professor Ohno and Continuous Cast Copper (not extruded but poured copper wire) that is rolled to fine strands as needed. Next they cryogenic treat the wire while demagnetizing the wire - in effect aligning the electrons while freezing to below -190 degrees Celsius which tightly compacts the atomic structure and aligns pos/neg charges.



Greg I have been working with metallurgy for 32 years and have watched copper and everything else come out of the caster and formed into various objects and I can say without hesitation that the wire is not poured. It is shaped into billets and beat into a shape the mill can use. The copper is then worked and worked through rolling, forming and then ultimately drawing into moderate diameter wire. Once in that shape it goes to specialty shops and is then drawn and stretched to the size needed. They dont roll it that small. 
As far as Cryo treating, I have been in those shops as well and there seems to be some agreement that the electrical resistance is reduced somewhat. Either way, you hear the difference and I believe that. How it is made is not quite as important as how it sounds.


----------



## JerryLove

Gregr said:


> The point I'd like to make is..., I found HTS while searching for high copper content wiring. I did not get much help on this here but did eventually find Furutech.


Perhaps this is better suited for a thread on wires?


----------



## Savjac

JerryLove said:


> I don't follow. How does the fact that 50% of respondents believe they hear differences mean that the issue is not psychosomatic?



Seems this statement works in either direction and therein lies the reason to discuss. Hearing or not hearing can equally be psychosomatic. Could be a good number of reasons that have nothing to do with this idea. It is true that placebos do have an effect on people which is a form of suggestion, take this pill for example and it might work. Conversely, the very suggestion or belief one cannot hear things could trigger the same problem in that there is no way the suggestee will hear a difference.


----------



## JerryLove

Savjac said:


> Seems this statement works in either direction and therein lies the reason to discuss. Hearing or not hearing can equally be psychosomatic.


I think the correct term at that point is "Perceptual bias" (which would apply to both). But I agree with you. I've never appealed to the "50% say they don't hear it" as proof it doesn't exist. I believe you made exactly that appeal in your previous post.

A great number of people cannot hear frequencies above 18khz. I know I could hear above 20khz at least until I got rid of the last source of such sounds in my house in my 30s. These days, I'm never quite sure if I really hear it or if my ears just ring at a very high pitch; as it's no longer as loud and source tied as when I had a CRTV (left on but with no signal, they could be heard).


----------



## Savjac

That sound may have been the flyback transformer. That used to annoy me in quiet rooms as well. Sometimes it got downright awful.


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## terry j

Savjac said:


> Seems this statement works in either direction and therein lies the reason to discuss. Hearing or not hearing can equally be psychosomatic. Could be a good number of reasons that have nothing to do with this idea. It is true that placebos do have an effect on people which is a form of suggestion, take this pill for example and it might work. Conversely, the very suggestion or belief one cannot hear things could trigger the same problem in that there is no way the suggestee will hear a difference.


This is the point in the argument.

All (I think) agree that there is no 'proof' to be found from those who say they cannot hear a difference, in other words there is little use in relying on my results that there is no diff between amps. Then again, I am making the claim there is no diff between amps (within the constraints laid out many times)

*You* (the opposing view) on the other hand ARE the means to falsify the claim of no difference, by demonstrating you can reliably pick between those two amps in a controlled test. Obviously to do that you need to differentiate between amp A and amp B. 

That is where the whole thing falls down. Very _very_ few of the claimants will ever get to that stage of attempting to demonstrate proof. Just a few posts ago it was suggested that someone enlist help to do a blind test, it was rejected out of hand.

There may be the figure of close to fifty fifty regarding this question in the poll but that does not show any evidence for the_ existance_ of differences but merely belief of differences. I hope that can be seen. 

When taking into account the results of _actual testing_ then the true figure indicating differences changes dramatically.


----------



## Savjac

terry j said:


> There may be the figure of close to fifty fifty regarding this question in the poll but that does not show any evidence for the_ existence_ of differences but merely belief of differences. I hope that can be seen.
> 
> When taking into account the results of _actual testing_ then the true figure indicating differences changes dramatically.


Indeed, but from my seat, the 50/50 poll indicates that there is no belief in the thought that there are "_no differences_", but rather, the suggestion that the participants going into this listening environment will hear no differences. I would be willing to do a test, but in a place that is comfortable and familiar to me. 

The "_actual testing_" seems to always take place on foreign soil, that is foreign to the testees ( is that a word ?) but NOT foreign to the tester. The music is brought to the site by the participant (s) but it is played under the duress of being in a completely non familiar place, knowing someone is challenging the participant with the thought in mind that the challenge comes from a negative place. If we can make some folks do better by the power of suggestion, and that happens a good deal, I am sure we can alter folks perception in the negative the same way.

Of all the people that have indicated they cannot hear a differences, there are thousands that say they can, proof being the varying amounts of gear bought on a regular basis.


----------



## Sonnie

Savjac said:


> I would be willing to do a test, but in a place that is comfortable and familiar to me.


That would be totally acceptable and is exactly what happened in the Zipser test in the first post... in his own home and under his supervision and per his request. He still could not tell a difference





Savjac said:


> ... there are thousands that say they can, proof being the varying amounts of gear bought on a regular basis.


That would in no way indicate any kind of proof. Indeed there are some who buy different gear because they think they can hear a difference, but it does not prove they can. The only way it can be proven without any doubt is via a DBT... which has never been done.


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## Gregr

I think I can get my hands on a nice old Technic's Receiver for your test. This receiver will meet all of the necessary requirements except/including its a lousy receiver. Or..., maybe I can pick up an Insignia at Walmart??

I hope you do this Savac. I believe in you man!!! Just enough to introduce some doubt to the conversation.


----------



## Savjac

Sonnie said:


> The only way it can be proven without any doubt is via a DBT... which has never been done.


I understand your point of view, totally and if I had not heard these differences, I would not be continuing this conversation. Your point of folks buying different equipment is well taken although how would one explain the amount of folks out there that state without equivocation that they can hear what we are discussing. There are many things that a large number of us believe that cannot be proven by any known testing procedure so out of this knowledge comes my beliefs. Sometimes it takes a good understanding of what to listen for and what to hear. I personally believe that these differences cannot always be determined in these tests, even if they rules allow for control of the time utilized to listen as dictated by the participants. 

This is not the best example but Imagine if you will that your best friends are exact twins and over the years of hanging with these friends you have learned to tell the differences in them by their affectations, mannerisms, a mole on the cheek of one but not the other, and other patterns that can only be determined over a period of time. Now you have them down pat and when in their presence or while having a long discussion with them, you can break through their sameness and tell them apart. Now put them behind a screen to where you cannot see them and they have been told to speak identically or as close as they can. Now, you have to formulate questions and listen to them closely and carefully to be able to make a determination as to which twin is A and which is B. Without time, or a tell, you may not be able to pull differences out of them. Now lets go one step further cause there to be distractions about you in way of people hanging on, looking at you, talking, fans going, AC on and off, and the threat that if you cannot tell the difference you have to spend the next 8 weeks listening to nothing but yoko ono music. That is called PRESSURE. :yikes:

Thoughts ??


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## JerryLove

Savjac said:


> The "_actual testing_" seems to always take place on foreign soil, that is foreign to the testees ( is that a word ?) but NOT foreign to the tester.


You think the tester hasn't tried the test on himself and failed to find a difference before inviting others?

Wasn't my suggestion a few posts ago to bring a friend over to the posters house to help him test his own equipment in his own room?



> If we can make some folks do better by the power of suggestion, and that happens a good deal, I am sure we can alter folks perception in the negative the same way.


fortunately: your hypothesis presents a falsifying test.

Hypothesis: the conditions of a DBX test make it impossible for the testee to hear real differences in sound.

Well. If that's true: we should find them unable to tell speakers apart in a DBX test; but we can.
We should find them unable to tell amps apart when one is set +5db (not level matched); but we can.
We should find them unable to tell a clipping amp from one which is not; but we can.

So apparently DBX tests can identify differences in speakers, and in volume, and in clipping amps. What is special about non-clipping amps that they cannot be heard in a DBX.

I suppose you could say "the differences are much more subtle", but I don't hear people buying new amps (or cables) and saying "the sound was very similar but there were some subtle differences". given the nature of memory (seconds for that level of detail), it would be impossible to tell subtle differences in audio except with A/B switching.

And why not solve the issue by stetting up one at your house with your equipment? That's what I did.


----------



## Savjac

JerryLove said:


> You think the tester hasn't tried the test on himself and failed to find a difference before inviting others?
> 
> Wasn't my suggestion a few posts ago to bring a friend over to the posters house to help him test his own equipment in his own room?
> 
> 
> 
> fortunately: your hypothesis presents a falsifying test.
> 
> Hypothesis: the conditions of a DBX test make it impossible for the testee to hear real differences in sound.
> 
> Well. If that's true: we should find them unable to tell speakers apart in a DBX test; but we can.
> We should find them unable to tell amps apart when one is set +5db (not level matched); but we can.
> We should find them unable to tell a clipping amp from one which is not; but we can.
> 
> So apparently DBX tests can identify differences in speakers, and in volume, and in clipping amps. What is special about non-clipping amps that they cannot be heard in a DBX.
> 
> I suppose you could say "the differences are much more subtle", but I don't hear people buying new amps (or cables) and saying "the sound was very similar but there were some subtle differences". given the nature of memory (seconds for that level of detail), it would be impossible to tell subtle differences in audio except with A/B switching.
> 
> And why not solve the issue by stetting up one at your house with your equipment? That's what I did.


Is this a post that would further the discussion or might this be a post that seems intent on bashing ones beliefs down another ear canal ?

Differences are more often than not subtle, mainly in the arena of the heavy hitter amps. And I will completely admit that some amps will sound very close and may not have a classic tell that would allow the listener to hone in on that difference in short order. There are some amps that by design may sound different from other well designed amps. There are some amps made by the same company that will not have the house sound, this happened with a good number of companies. I do remember a test attended by Bob Carver when he was challenged to make one of his amps sound like another companies and after several failures, admitted failures, he got it so close that no once could reliably tell the difference between the Carver Ampenstein and the goal post amplifier. I cannot imagine that the listening panel would admit over several incarnations that he was a failure and then later in the test, admit he finally got it right. Well unless those participants were members of our congress, then I believe they would lie just to try to create a sonic cliff. (Yeah that was bad)

Is it possible that with a properly set up system, using a signal source that can really show the differences in sound, that you may be able to hear a difference or has that boat sailed ?


----------



## Savjac

Gregr said:


> I think I can get my hands on a nice old Technic's Receiver for your test. This receiver will meet all of the necessary requirements except/including its a lousy receiver. Or..., maybe I can pick up an Insignia at Walmart??
> 
> I hope you do this Savac. I believe in you man!!! Just enough to introduce some doubt to the conversation.



Thank You Greg, you crack me up. I am quite sure that I can prove, to an open mind, that differences, do exist, that is meaningful differences as long as they do not add 6 billion conditions. The question is, do all amps sound the same. We can even allow classes, you know like the minors in baseball or WPC etc. Not sure how to run a proper test, but I am sure there is one.I think we can even demonstrate that there may be a difference in....tada....cables. Ahhh maybe I am preaching to the choir here eh ?? lddude:

Based upon the poll here, my chances are at a minimum even. :heehee:


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## Sonnie

Savjac said:


> Is this a post that would further the discussion or might this be a post that seems intent on bashing ones beliefs down another ear canal ?


C'mon now Jack... Jerry's reply was directly responding to your comments/questions and he was very courteous and polite. It is actually your comments like this one that are out of line and provoke negative responses. Everyone is being very nice, just laying out the problems with your thinking/analogies... holes in your reasoning, if you will.


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## JerryLove

Savjac said:


> Thank You Greg, you crack me up. I am quite sure that I can prove, to an open mind, that differences, do exist, that is meaningful differences as long as they do not add 6 billion conditions.


2 = 6 billion?

1) The amps must be sufficient to the speakers (not clipping). We all agree that clipping amps don't sound the same. I agree that my AVR does not sound the same powering my 801's as my old McIntosh does. But my Yamaha and McIntosh do sound the same; and they all power my PSB 400i's the same.

2) The amps must be set to the same gain as each other. We all agree that different volumes sound different.

And I've done this test more than once myself and with others. (fortunately: almost all the amps I personally own have gain controls). The hardest part is trying to arrange rapid switching on a single set of speakers. I've seen devices that do it; but manually it's a pain and not instant.


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## Savjac

Well then I must apologize as I actually thought I was being nice, that is my mistake indeed. I guess the written word is not always in my favor, I actually do much better in an actual verbal discussion. I am sorry.

Can we admit that both Tom Nousaine and Peter Aczel, the gents that posted the reports at the beginning of this forum are admittedly on the side of not hearing significant differences in amplifiers ? If I were to post 2 reports by gents that can hear a difference, and can describe those differences quite clearly, would that even the evidence somewhat ?


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## JerryLove

Savjac said:


> Can we admit that both Tom Nousaine and Peter Aczel, the gents that posted the reports at the beginning of this forum are admittedly on the side of not hearing significant differences in amplifiers ? If I were to post 2 reports by gents that can hear a difference, and can describe those differences quite clearly, would that even the evidence somewhat ?


If two people are chosen for some reason other than they described an amp's differences the same way (IOW. Not cherry picked)

If those two people do not generally use the same descriptors for all amps they like. (IOW, there's a large number of possible descriptors)

If those two people then pick the same descriptors for the "difference" in sound; with no knowledge of each others posts.

If there was no particular shared reason for this (such as that is what the manufacturer claimed it would sound like)

Then that would support a hypothesis that a) the amps sounded different and b) they sounded different in the way described.

Lacking any other data: I would consider the most likely case the above hypothesis. But statistically: 2 is not a viable sample set. , and I don't lack other data. In light of the rest of what I know, the inference of the data is not compelling. I'm forced to conclude that there is another variable at work (or simple coincidence). A more controlled study, or *much* larger sample set (which would be difficult to establish a lack of cross-contamination on) would be far more compelling.

I didn't read either but let me take a guess. Some of the words included "blacker", "more musical", "more defined" (I would also accept "nuanced) , something about "silibance" , and they particular focused on mid or upper frequencies. Because that's what people usually say about power-cables, speaker wire, and amps.


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## Sonnie

What would be neat is if we could find 100 willing people out of the thousands who claimed they can hear a difference (pick only those claiming to have golden ears... or have a mixture... either is fine) and have them participate in a DBT... maybe even use those same amps that Nousaine and Zipser used. If a difference can really be heard, would not the majority of those 100 be able to clearly describe the difference that makes the Aleph's cost tens of thousands more? 

I would _guess_ (based on previous tests) that less than 5% would be able to differentiate between the two amps more than 5 out of 10 times... and those that did would be merely lucky and the percentage would be so low it would not be sufficient to prove there is in fact a describable difference.

I really do not know what I would do if I were wealthy enough to buy any amps I so desired to buy, because money can have a significant influence on some people and heavily influence our decisions (I am not speaking for everyone). I would like to think I would be wise, but who knows... I may buy the more expensive amps just to say I have them, to make me feel better, whatever... but I would like to believe that I would be wise enough to take into consideration that if I spend tens of thousands on more expensive amps, they would _improve_ the sound of my system respective of the increase in price.


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## Savjac

Interesting thoughts. Personally I do not know that one of the test amps sounds better than the other, I have not heard either of them. I noted that the tests were posted by two men that work together with no counter discussion from two men that do not work together but may feel the same about what they hear. I do not have 2 posts in mind, I have 2 reviewers in mind but that was about it. There was not under handed thoughts on my part to try to load the posts with junk from reviewers I have not respected for at least 20 years. I was thinking more in line with Art Dudley and Anthony Cordesman. The two gents could not be more different, in that one is a musician writer and one is an expert in history and conflicts in the middle east, acts as an adviser to the feds and was quite prevalent on tv during that last war.

It would be nice to have some folks have a nice sit down and do a listen to different amplifiers as in reality it would show us all something, myself included. If under the proper circumstances, in a good environment of learning and fellowship, I think a good deal could be learned and if there are no differences, then even I would have to rethink my sincere beliefs. 

I was talking to a fellow listener and music lover tonight and we both agree there are differences we have heard over the years doing long term testing ourselves. I would like to think we are not fooling ourselves, but stranger things have happened. I don't know, maybe there is no single answer, maybe there are just more questions.

Lastly, I am not sure that expense is always a factor in this in that I am sure there are some expensive lemons out there and some inexpensive gems, although it may be a good bet that if you have enough and spend enough, you may improve your sonic lot...no guarantees though.


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## Gregr

I am finally in agreement with this line of thought. It really would be a fun thing to get together with kindred souls who appreciate great music and furthering the Audio industry. With some truly unbiased testing, simply for the sake of knowing or understanding this question and simply to add data in the hope of one day resolving this seeming audio anomaly . Maybe again there is no direct answer and with enough information we find the data actually shows a 50 50 split of statistical evidence.


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## JerryLove

I've got a few amps to bring to the party.


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## Dub King

I suggest a re-read of the 'Stereophile Bob Carver Challenge'

It establishes two things - that any two amps CAN sound the same, and that in general no two amp designs _actually_ sound the same unless _deliberate_ effort is made to 'make it so'. It also outlines exactly how to extract the 'difference' between the output of two amps and literally listen to it as a by-product of cancellation. It's elegant proof that differences exist, can be quantified... but also can be eliminated. The article also establishes that 'good' sound is the result of meticulous engineering, not expensive materials... so if there is a take-away it's that money isn't everything when it comes to amps and SQ.

The article even bumps into the fact that there is always room for improvement - cheap amps can be tweaked to sound _better_ than flagship audiophile amps... I've certainly made that argument before as to why I'd never buy a Krell.

Are we now claiming that amplifiers will never, ever sound better than they already do (as of 2013) except for added efficiency and power handling? If we're there I can accept it... just like how digital cameras eventually became so good, megapixel counts stopped mattering much... it's all about the post-processing. Certainly I'd laugh if someone told me they could tell what brand of camera a photograph was shot with. I'd know that if I analysed the noise/grain structure using Photoshop I could potentially figure it out, but can a human being use their _unaided_ senses to differentiate? No.

I am a pro when it comes to photography, my own analogy makes it clear I was not thinking clearly about this topic. Switching to 'most people cannot hear the difference' - for all practical purposes it's the least important thing to worry about. Modern amps sound good.


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## JerryLove

Stereophile? 

Yep. They do hear differences between amps, and cables (http://www.stereophile.com/category/cable-reviews/), and fuses (http://www.stereophile.com/content/hifi-tuning-fuses).

Forgive me if I just don't trust Stereophile reviews. 



> Are we now claiming that amplifiers will never, ever sound better than they already do


I'm willing to say that they will never, ever, sound better than the good ones did in the 1970s (likely before that; but that's outside my experience). I've not found a modern amp with a sound advantage over my McIntosh 2120 from the late 1970s.


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## Gregr

So, by setting up the comparison as Zipser' example and per discussions here we are actually setting up two diff amps to sound as similiar as humanly possible and expecting some body to tell the difference. 

If we had not so many distractions we may have actually discovered this on our own. Thank you for adding some interesting points Mark. I do apologize for my part in distracting others if that's possible. 

If we ever get to a point in our conversation where a test is possible and the next logical step I would like to offer an A/B test protocol or I suppose we can discuss this at that time. Sounds like to me we have more to discuss and maybe more to consider. After all the question is "Can we really hear a difference?"

Please no more outrageous rebuttals about clipping, or digging up other argumentative points from the last great discussion that was obviously before my time here. The question for me is can we discuss this new information while keeping an open mind to both sides.

There is a saying


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## Dub King

You've read the article, right? It's not a review. Bob Carver was calling Stereophile's bluff. The man knows a lot about amplifiers. It certainly was a mea culpa for the entire editorial staff of that magazine, but at least they admitted it. Boutique amps do not sound better than 'cheaper' options - but they do typically sound different. The trick is two amps _can_ be made to sound identical. Cloning is possible.

Stereophile has said many nice things about McIntosh amps over the years. I guess that was all wasted ink, right? They simply pretended that McIntosh amps sound better because in fact they do not. 

So, you cite your own amp as the moment perfection was achieved lddude:... and so you are saying that since then all amps sound exactly like your 'benchmark' McIntosh :rofl:... because that's what the 'can't hear a difference' crowd is saying :devil:. Sounds fishy. I think someone with good ears who knows what they are doing can tell the difference between amps. Amps exhibit quantifiable differences in how they reproduce sound, proven in a lab. It's not too different from Wine or Scotch. You really don't want to waste the good stuff on people incapable of appreciating it and for those people who cannot 'appreciate the difference' - usually due to 'amateur palate' in oenophile terms - paying extra is meaningless... actually a waste of _their_ money.

I'm willing to say the Sony TA-N77ES amps I used to own sounded better than the McIntosh 2120. It certainly had better specs - More power, lower THD and considerably more linear especially in the bass region. I rocked a pair for a decade. http://kenrockwell.com/audio/sony/ta-n77es.htm#spex




JerryLove said:


> Stereophile?
> 
> Yep. They do hear differences between amps, and cables (http://www.stereophile.com/category/cable-reviews/), and fuses (http://www.stereophile.com/content/hifi-tuning-fuses).
> 
> *Forgive me if I just don't trust Stereophile reviews. *
> 
> 
> 
> *I'm willing to say that they will never, ever, sound better than the good ones did in the 1970s (likely before that; but that's outside my experience). I've not found a modern amp with a sound advantage over my McIntosh 2120 from the late 1970s.*


----------



## Gregr

One additional thought...,aren't we really attempting to discover if an individual can identify a diff between the two amps that he/she is already familiar with? Or, aren't the Yes respondents really saying, yes I could hear a difference when I changed from the outlaw amp and preamp to the Rotel AVR. 

Granted the newest amp is still an unknown in many ways but we have a sense of improvement or difference even beyond the added features and ability to add more speakers. In my last buy I bought another Denon because I liked that I heard a difference with each tweak. Whereas with the Harmon Kardon, I could not improve it in any way except by moving the speakers around. But nothing I did could improve the mids that never seemed to fully bloom. I know some of you are frustrated by these more esoteric descriptors but please allow this one. But the point is both I am familiar enough with that I can easily say there is a difference.


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## Gregr

Mark I am going to read it now. I could get through it without falling asleep..., I hope.
If not well you've sure got my interest.


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## chrapladm

Well I know I cant hear the difference between most pro audio amps. I can tell where there is a weak power supply and there for the amp lacks power in the lower octaves but thats about it.

If both pro audio amps are being tested with the same SMPS or toroidal power supply with similar capacitance from known quality manufacturers I can not tell the difference. If others can thats awesome but not really useful for me.

I just wish manufacturers would test there amplifiers at 20hz rather then a 1khz. Give me 20hz, 1khz, 20khz sinewave and 20-100ms burst at those frequencies. Then A/B them if they are rated the same. Seems like technology is always improving on the past. I am not saying all but I would put my money that the newer amplifiers of today far exceed that of the others of yesterday.


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## Dub King

Pro audio amps by and large sound identical to each other in my experience as well, and there is no motivation for pro amp manufacturers to try and differentiate. Flat _is_ flat to them. A Lab Gruppen clone, a Crown XTi and a Behringer EP 4000 all sounded the same to me and also to a number of others present at a GTG I went to a few weeks back... so long as they are not clipping. I would describe the sound of pro amps as neutral, tight, clinical. I use them to power subs, but have not enjoyed them as much for high frequency reproduction. 



chrapladm said:


> Well I know I cant hear the difference between most pro audio amps. I can tell where there is a weak power supply and there for the amp lacks power in the lower octaves but thats about it.
> 
> That being said if both pro audio amps are being tested with the same SMPS or toroidal amplifier with similar capacitance from known quality manufacturers I can not tell the difference. If others can thats awesome but not really useful for me.


----------



## JerryLove

Dub King said:


> You've read the article, right? It's not a review. Bob Carver was calling Stereophile's bluff. The man knows a lot about amplifiers.


Yep. Read a lot from a lot of amplifier and audio professionals who know a lot about amplifiers besides that too.. 

And let's focus on two important parts of the article:
1) "It is true that there were no "controls" here—no double-blind precautions against prejudices of various kinds."
2) "They were almost a perfect match, except for a slight difference in perceived depth and perspective, a marked difference in low-frequency range and control, and a noticable difference in high end smoothness."

#1 is pretty self explanatory; #2 addresses the appeal to Mr.Carver's authority* in determining if these differences exist. He did his work, produced a result, and was (according to this test) wrong. 

*I have no doubt in Mr.Carver's skill as an amp designer. 



> Stereophile has said many nice things about McIntosh amps over the years. I guess that was all wasted ink, right? They simply pretended that McIntosh amps sound better because in fact they do not.


Not wasted ink at all. They made a lot of money writing that.

Does your comment mean you will be buying fuses to improve your sound? Or are you ignoring *that* stereophile review?



> So, you cite your own amp as the moment perfection was achieved


Not quite. I cited it as an example of a flat, sufficient amp. It becomes a minimum "how far back". As far as I know, there were identical sounding amps in the 1940s. 



> and so you are saying that since then all amps sound exactly like your 'benchmark' McIntosh


If they are sufficient to the speaker they are driving and not deliberately coloring the sound then, yes.



> I think someone with good ears who knows what they are doing can tell the difference between amps.


None of them has ever proven so when tested.



> I'm willing to say the Sony TA-N77ES amps I used to own sounded better than the McIntosh 2120. It certainly had better specs - More power, lower THD and considerably more linear especially in the bass region.


I'm sure it does: from 121w - 200w output (well, neither of our amps' specs are likely completely accurate, and speakers don't have constant ohm loads, but I assume you get the point). The THD is inaudible in both amps so irrelevant. Non-clipping amps are not a significant source of HD.


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## Dub King

I understand your points. The ideal amp is transparent, and modern amps come close enough to that ideal that most people cannot hear differences. That's the thrust, I get it and I agree with it. I'll be skipping the fuses, thanks... I don't believe in hocus pocus audio tweaks. The fact that major newspapers publish horoscopes doesn't automatically discredit the front page headlines. News is news. How the news is interpreted is a whole another story. It's much like the argument over the value of premium vodka - technically they should all be the same, and Everclear mixed 40/60 with spring water should also be the same thing... but some do taste better than others, and some cause hangovers much more easily than others.



JerryLove said:


> Yep. Read a lot from a lot of amplifier and audio professionals who know a lot about amplifiers besides that too..


----------



## terry j

Savjac said:


> Indeed, but from my seat, the 50/50 poll indicates that there is no belief in the thought that there are "_no differences_", but rather, the suggestion that the participants going into this listening environment will hear no differences. I would be willing to do a test, but in a place that is comfortable and familiar to me.


Sorry, did not quite follow the first bit, but yes to the last sentence which you expand upon.



> The "_actual testing_" seems to always take place on foreign soil, that is foreign to the testees ( is that a word ?) but NOT foreign to the tester. The music is brought to the site by the participant (s) but it is played under the duress of being in a completely non familiar place, knowing someone is challenging the participant with the thought in mind that the challenge comes from a negative place. If we can make some folks do better by the power of suggestion, and that happens a good deal, I am sure we can alter folks perception in the negative the same way.


Not sure that your assumption is true that these tests 'always' take place on foreign soil..think you may have just added that bit in..but yes completely, the test should take place on that persons own system in their own home and with amps that they already believe they can tell apart. In fact, everything should be done to maximise the chances of success, they choose the music, they choose when to switch, they choose which parts to listen to (the 'killer' section), they choose the methodology (instant switching or manual changing of amps and leads), in short whatever they are most comfortable with.



> Of all the people that have indicated they cannot hear a differences, there are thousands that say they can, proof being the varying amounts of gear bought on a regular basis.


There seems to be a constant disconnect here. Yes, there are many many claiming with the utmost conviction that they here differences. Further to that, not one person (well, at least me) does not believe them, you tell me you hear differences then not for one second do I think you are lying.

There are however many completely researched and documented ways in which peoples perceptions can be fooled. That is NOT the same thing as saying you are a fool, that you are foolish or anything of the sort. (the general you)

It is simply saying that as a species human perception can be swayed by external factors. So in order to _isolate_ any real sonic differences those perception confounders need to be controlled for. We ALL accept our senses can be fooled when we watch a magic show, not one of us really thinks they sawed the woman in half and put her back together again do they?

But for some reason, when it comes to audio (or sense of hearing) that very idea is met with extreme resistance when in other areas of life it is fully accepted. I have never quite understood why myself.

Note, that is not the same thing as saying there are no differences, just that any differences have to be identified by sound alone.



Savjac said:


> This is not the best example but Imagine if you will that your best friends are exact twins and over the years of hanging with these friends you have learned to tell the differences in them by their affectations, mannerisms, a mole on the cheek of one but not the other, and other patterns that can only be determined over a period of time. Now you have them down pat and when in their presence or while having a long discussion with them, you can break through their sameness and tell them apart. Now put them behind a screen to where you cannot see them and they have been told to speak identically or as close as they can. Now, you have to formulate questions and listen to them closely and carefully to be able to make a determination as to which twin is A and which is B. Without time, or a tell, you may not be able to pull differences out of them. Now lets go one step further cause there to be distractions about you in way of people hanging on, looking at you, talking, fans going, AC on and off, and the threat that if you cannot tell the difference you have to spend the next 8 weeks listening to nothing but yoko ono music. That is called PRESSURE. :yikes:
> 
> Thoughts ??


Most analogies fall down somewhere, this is no exception. Firstly, why twins? Because they look pretty identical. But let's make it simply brothers, not twins. You don't think you could tell two brothers apart you knew really well (even if they talk the same) by asking them questions? If not, then you perhaps did not know them quite as well as you had thought. (favourite foods, bands yada yada)

Same deal with amps maybe...when behind a screen and you find it difficult to tell them apart (night and day before) then maybe you did not know them quite as well as you thought? Ie, there is less difference in reality?



Savjac said:


> Can we admit that both Tom Nousaine and Peter Aczel, the gents that posted the reports at the beginning of this forum are admittedly on the side of not hearing significant differences in amplifiers ? If I were to post 2 reports by gents that can hear a difference, and can describe those differences quite clearly, would that even the evidence somewhat ?


There is not and never has been doubt that people hear differences and can report those differences in the most exquisite prose. That however is simply a continuation of the problem. What do we do about the myriad ways in which our perceptions can be fooled?

It would most certainly even out the evidence if they were able to describe those exact same differences even when blinded.



Sonnie said:


> I would _guess_ (based on previous tests) that less than 5% would be able to differentiate between the two amps more than 5 out of 10 times... *and those that did would be merely lucky* and the percentage would be so low it would not be sufficient to prove there is in fact a describable difference.


Is that not a case of already deciding the issue? We ask *them* to do a test, set the bar to jump then turn around and say it was just a lucky guess? No wonder there is a deep suspicion about the intent of those pushing for tests.

ALL decide beforehand what the test procedure is, how many tests/trials will be done, use statiscal analysis data to agree on an acceptable level for correct results and then that is it. Neither side can then backtrack.

The knife cuts both ways.



Sonnie said:


> What would be neat is if we could find 100 willing people out of the thousands who claimed they can hear a difference (pick only those claiming to have golden ears... or have a mixture... either is fine) and have them participate in a DBT... maybe even use those same amps that Nousaine and Zipser used. If a difference can really be heard, would not the majority of those 100 be able to clearly describe the difference that makes the Aleph's cost tens of thousands more?


(the thread has taken a positive turn recently)

This would be a fantastic thing to organise. I don't know how many of you have been to gtg's etc, but they ARE tons of fun and usually a damned good time for all concerned. In my experience the animosities (real or imagined) that people might feel exist on forums disappear, and what you end up with is a bunch of enthusiastic people with the same interests meeting and greeting.

Once that level has been achieved, then most are up for learning, both sides. After all, there could very well be a person who can easily tell the amps apart ten/ten. Then *WE* have to eat humble pie. (it can be tough hitting our own barriers tho!)

The trouble is for a big test like this is that it violates it being done on the persons own system with amps of their own choosing. So whilst it would deliver some insights there would always be nits to be picked.

Good fun tho, organise it sonnie!!:sn:


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## lcaillo

terry j said:


> There is not and never has been doubt that people hear differences and can report those differences in the most exquisite prose. That however is simply a continuation of the problem. What do we do about the myriad ways in which our perceptions can be fooled?


Here we have the beginnings of getting to the real issue. That is, IMO, that both sides are really not interested in the same questions. Those who experience differences and describe them, whether eloquently or not, are being challenged by those who have not had the same experience. The two sides here don't even agree that there is a problem to be solved. The "problem" as you put it is really a meaningless question to someone who is certain that they have experience a difference and is happy with that. For the person who is trying to make more objective decisions about selecting products and wants some basis other than subjective experience of others, the articulation of personally experienced differences does not begin to be sufficient.

Both sides are starting with a belief, an opinion. That is easy to see for the objectivist in the other, but we have to realize that those who have not experienced differences are also biased by that very lack of experience.



terry j said:


> It would most certainly even out the evidence if they were able to describe those exact same differences even when blinded.


Of course, but this is not so simple. In requiring them to do so, we are asking for objective identification in a limited setting of an experience that is the sum of much more than a limited listening event. If, on the objective side, we are going to say that much of what is experienced is not grounded in actual differences but in very complex biases that even the subjects of the experiment do not acknowledge nor understand, yet construct the test in a manner that only proves the part of the "question" that we would like to believe is true, are we any better than the other side? Are we really contributing to understanding?



terry j said:


> The knife cuts both ways.


That, ultimately, is my point. We must, however, understand that the two sides are cutting different materials, with very different tools, with very different expectations of what is important as a result.

My belief is that there are differences in amplifiers but they are not consistent with the myriad of flowery descriptions of many audiophiles and vendors. Nor are those differences as common as they would have us believe in terms of measurable and repeatable experiment using either electronic testing or DB listening tests. It seems clear to me also, however, that many of those reporting those differences are perfectly happy with their experiences whether they are based in physical reality that the rest of us can understand or not.

People buy products all the time for reasons that have nothing to do with objective decision making. It is perfectly reasonable to try to get to the objective evaluations that are more useful and meaningful in parsing reality and experience, but we have to understand that doing so is not everyone's priority.

If we really want to better understand both sides of this double sided mirror, we should do a better job of identifying with electronic testing the differences that can be objectively determined in listening tests that are blind. That starts, not with a hundred people, but one. If one person can repeat reliably a test that blindly identifies a difference, then we should test the devices to determine how that difference can be described in objective electronic testing. Only then will we begin to cut with both sides of this double edged knife.


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## Savjac

I have been taken to task on occasion of late for my poorly worded and possibly condescending know it all posts. Trouble is, I had no clue I was doing it so I asked my lovely bride if she had noticed this in my day to day discussions at home and the answer was delivered in the positive. YIKES, that was not quite what I had hoped for but it did tell me I have been somewhat of a dolt of late and had better look into that post haste. After a night of deliberation, I think I know what the problem is and will work to correct that. In the meanwhile, I will work hard on being as even keeled as possible in my posts and if I go wrong much more, it may be time to just read and not say or type much. I actually went back after several years and re read the rules to ensure I try to stay within the forum guidelines at all times. 

In moving forward from those thoughts an interesting thought came upon me but I am not sure from which frame of mind it occurred. In reading some of the rebuttals back and forth in the continued posts regarding this subject it seems to me in my admittedly less than stunning frame of mind that the onus to prove something or disprove something lies only on one side of the discussion. Namely, if we can hear a difference, we have to prove the existence of those difference repeatedly under conditions agreed to by parties that follow the two trains of thought. However, for the folks that do not believe there are differences, the only proof needed is to say, there are no differences. 

As with the article presented earlier, Carver did an unknown number of tests with his ears and equipment to change the sound of one of his amplifiers. The fact that he changed the sound at a minimum should bear proof that all amplifiers do not sound alike. The fact that he was able, after a great deal of time and trouble, to cause his amplifier to sound like another, speaks to the fact that all amplifiers _Could_ be made to sound alike should one wish to. The idea here seems to be that since we all hear things a bit differently, the designer of any given amplifier will design it to fulfill his or her sense of what is right within the budget the designer chooses to set. As mentioned in an earlier post, I cannot believe that more expensive always equates to better. 

If the articles provided at the opening of this particular thread are provided as evidence to support one side of our beliefs, then the Stereophile article surely can stand with equal authority to discuss the second side of this discussion. It is quite scientific, electronic testing was used and shown to the parties involved and was attended by a good many authorities in this field with most excellent credentials.


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## lcaillo

Carver had the right idea, in my opinion, with the notion of defining the transfer function of an amp. When we look at specs for amps, we really don't come close to that. In the same way that we now look at color in displays in terms of many test points instead of just three color measurements and one white point, we should be evaluating amps more completely. I would like to see power bandwidth measured at multiple points and into complex loads to see how various amps actually map response to more realistic conditions. 

A few years ago when a handful of calibration geeks suggested that we needed to map more points in color analysis of displays, most laughed it off. Now it is considered to be quite useful when it is done in some of the automated systems now available. Some displays show error that was not captured by more limited measures, while most are pretty well described and corrected with the more simplistic measures and limited controls. The same is likely to be discovered with amps. There is likely more difference than the naysayers would like to believe, and far less than the subjective observer of differences would suggest.


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## J&D

Great discussion on this topic. Familiar with the Carver challenge to Stereophile and remember reading that article when first published as I was a long-time subscriber. Why it was most interesting to me is because all of the comparisons I participated in were several years prior to this test. 

One of the issues I have with this particular test is that what he is proving is his own ability to exactly match the output of two subject amps. They never reveal if Bob is attempting to make his solid state amp sound like a reference tube design or if they are proving that solid state amps have a signature sound that can be duplicated. These are two very different objectives. I think everyone that has listened to tube amps agree that they have a "sound signature" which is in fact particular distortion characteristics being added to the source. In either way we do not know what amp he was trying to replicate and thus the test falls far short of proving if two solid state amps sound different under similar conditions. 

Either way these tests have to be conducted blind and without the user having any knowledge of what amp is playing at any given time. This is a very simple test and nothing needs to be read into the motivation for doing it either way. The testing I participated in was initiated because I felt challenged by others who told me I was making a big mistake. I just wanted to find some evidence indicating that I had. Prior to my experience I was firmly in the camp that all amps sounded different. I would love to participate in another challenge and would love to see the results of the testing come out completely different.


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## Dub King

I would not claim that all amps sound different. In the Carver challenge article, that is touched on for a moment... 

_"Carver claims that the original, unmodified M1.0 amplifier had been designed to sound "the way he wanted it to." If, in fact, he could make it sound any way he wished, as seemed to be proven with his success in this experiment, *why then did he elect to go with a typical mid-fi "solid-state sound" instead of emulating the sound of one of the best-sounding solid-state or tubed amplifiers on the market?* There were, it turns out, some good reasons.

Bob admits that he is not sure himself about the audible effects of some of the parameters he juggled to match the transfer functions of his amp to that of our reference."_

There definitely is a 'standard solid-state sound' and it's objective is scientific accuracy i.e. the quest for the flattest, least distorted attenuation of the signal. The result is that quite a few amps do sound the same. 'Generic' one might say... while others would call it 'accurate'. It most certainly is the 'sound' of pro amps, where coloration is expressly unwelcome... but so is excess weight and cost.

Given the immense influence speakers and the room have on sound, I can't understand why anyone would even care if the designer of an amp makes minor tweaks to the sound in the name of 'getting it right'. 

The original question - if there is a difference to be heard - hinges on one simple factor, are there amps out there which sound distinctly different from each other, or not. The answer is yes, there are... if only because building an amp allows for it. The corollary is that there are plenty of amps that sound indistinguishable from each other.



J&D said:


> Great discussion on this topic. Familiar with the Carver challenge to Stereophile and remember reading that article when first published as I was a long-time subscriber. Why it was most interesting to me is because all of the comparisons I participated in were several years prior to this test.
> 
> One of the issues I have with this particular test is that what he is proving is his own ability to exactly match the output of two subject amps. They never reveal if Bob is attempting to make his solid state amp sound like a reference tube design or if they are proving that solid state amps have a signature sound that can be duplicated. These are two very different objectives. I think everyone that has listened to tube amps agree that they have a "sound signature" which is in fact particular distortion characteristics being added to the source. In either way we do not know what amp he was trying to replicate and thus the test falls far short of proving if two solid state amps sound different under similar conditions.
> 
> Either way these tests have to be conducted blind and without the user having any knowledge of what amp is playing at any given time. This is a very simple test and nothing needs to be read into the motivation for doing it either way. The testing I participated in was initiated because I felt challenged by others who told me I was making a big mistake. I just wanted to find some evidence indicating that I had. *Prior to my experience I was firmly in the camp that all amps sounded different.* I would love to participate in another challenge and would love to see the results of the testing come out completely different.


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## J&D

Dub King said:


> There definitely is a 'standard solid-state sound' and it's objective is scientific accuracy i.e. the quest for the flattest, least distorted attenuation of the signal. The result is that quite a few amps do sound the same. 'Generic' one might say... while others would call it 'accurate'. It most certainly is the 'sound' of pro amps, where coloration is expressly unwelcome... but so is excess weight and cost.
> 
> Given the immense influence speakers and the room have on sound, I can't understand why anyone would even care if the designer of an amp makes minor tweaks to the sound in the name of 'getting it right'.


Based on my experience there is "tube sound" but there is no "standard solid-state sound" that can be reliably singled out and identified in A/B/X testing. For me an ideal amp is a straight wire with gain. I would not be interested in any amp designers attempts at adding distortion they feel is "getting it right." Interesting concept but one that even Bob Carver has stayed away from.


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## JerryLove

Savjac said:


> As with the article presented earlier, Carver did an unknown number of tests with his ears and equipment to change the sound of one of his amplifiers.


That does not appear to be an accurate description of the process. Carver inverted one signal, fed them to each other (with equal dummy loads) and looked at the difference caused by the sum. He then made any changes he made to get them to sum 0 with 70db of resolution.

In addition to being curious about the specific changes made to accomplish this, and in addition to being curious about what the summed FR looked like in the first place; it is of interest to me that he "failed" the first time through and then (as far as I can read) without changing his procedure, succeeded.


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## Sonnie

Gregr said:


> So, by setting up the comparison as Zipser' example and per discussions here we are actually setting up two diff amps to sound as similiar as humanly possible and expecting some body to tell the difference.


No we are setting them up to sound similar... they in fact sound similar on their own... pretty much identical according to all who were present. The only adjustments made were to level match the amps within 0.1db at 1kHz.

From the first post: _A Pass Labs preamplifier, Zip's personal wiring, and a full Audio Alchemy CD playback system completed the playback chain. No device except the Yamaha integrated amplifier was ever placed in the system. Maki inserted one or the other amplifier into the system and covered them with a thin black cloth to hide identities. Zipser used his own playback material and had as long as he wanted to decide which unit was driving the speakers.

I had matched the playback levels of the amplifiers to within 0.1 dB at 1 kHz, using the Yamaha balance and volume controls. Playback levels were adjusted with the system preamplifier by Zipser. I also determined that the two devices had frequency response differences of 0.4 dB at 16 kHz, but both were perfectly flat from 20 Hz to 8 kHz._



terry j said:


> Is that not a case of already deciding the issue? We ask *them* to do a test, set the bar to jump then turn around and say it was just a lucky guess? No wonder there is a deep suspicion about the intent of those pushing for tests.
> 
> ALL decide beforehand what the test procedure is, how many tests/trials will be done, use statiscal analysis data to agree on an acceptable level for correct results and then that is it. Neither side can then backtrack.
> 
> The knife cuts both ways.


Keep in mind that I am not confirming that there is no difference in amps, merely suggesting there is none based on previous DBT proving no differences and no DBT to proves any differences.

The reason I suggested that those few that claimed to have identified differences more than 5 out of 10 times was mere luck is because it probably would be based on the fact we are talking about 100 people who claim to have golden ears and asking the question why were so few (less than 5%) able to hear differences. I could also add that I don't think (and I have no way of proving it before hand... just a hunch) that even those few (less than 5%) could hear a difference 10 out of 10 times. 

Keep in mind that I am only making a suggestion/estimate of what I think the outcome would be based again on previous testing that has proven no differences heard and the lack of no testing proving their are differences. I have absolutely no problem admitting differences can be heard if they can be proven. So no... the sword does not cut both ways with my suggestion because there have been no DBT that prove differences can be heard... if they had, I would not necessarily suggest/estimate the above. :T


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## lcaillo

I think most of us agree that getting it right is about approximating that straight wire with gain that you describe. I believe the assumption of most who believe that there is no meaningful difference in sound among properly designed solid state amps working within their designed range that we have essentially reached that point in amp design to the degree that we can audibly distinguish under normal circumstances.


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## Sonnie

Dub King said:


> Given the immense influence speakers and the room have on sound, I can't understand why anyone would even care if the designer of an amp makes minor tweaks to the sound in the name of 'getting it right'.
> 
> The original question - if there is a difference to be heard - hinges on one simple factor, are there amps out there which sound distinctly different from each other, or not. The answer is yes, there are... if only because building an amp allows for it. The corollary is that there are plenty of amps that sound indistinguishable from each other.


My question would be... what is "right"? If there is a difference that can be heard... is it an improvement in the sound? If so, how is it improved upon and to what extent?

If the builder of the amp says I want this amp to sound different from the "typical" solid state amp... is he changing the sound to what "he" likes or to a sound that would be considered an improvement to anyone listening?

FOR ME (I certainly cannot speak for everyone)... I think the entire point of making an amp sound different would be to improve the sound to a level it would be worth me paying more for it.


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## Dub King

If solid state always sounds like solid state, then that's 'standard solid state sound', just sayin'. 

If a solid state amp can be made to sound like a tube amp, then it will sound different from 'solid state sound'... but it will still be solid state. I think this has been established.

Therefore, there is a 'solid state sound' and it represents a standard - which I already identified as being flat and neutral, i.e. the hypothetical speaker cable with gain. The design goal is for these amps to sound the same. Clearly a successful endeavor as there are many amps out there which are in fact indistinguishable from each other. In fact, they 'define' the solid state category.

As for Bob Carver staying away from the concept... I really do wonder if you read what you are discussing. the very next paragraph:

_"Secondly, Bob had never before had a chance to listen critically to a "world-class" amplifier like the one we chose as our reference, and ended up admitting that there were things about its sound that he preferred to his own amp. He might, he averred, "do some things differently in future designs."_

Indeed he did, since Bob ran home with his tweaked amp and tried to clone it and sell the result.



J&D said:


> Based on my experience there is "tube sound" but there is no "*standard solid-state sound" that can be reliably singled out and identified in A/B/X testing*. For me an ideal amp is a straight wire with gain. I would not be interested in any amp designers attempts at adding distortion they feel is "getting it right." Interesting concept but one that even Bob Carver has stayed away from.


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## Dub King

I'm going to go with the old platitude about pleasing some of the people all of the time or all of the people some of the time. If you were an amp designer aiming for the high end and think a tweak is going to be a differentiating factor, you are aiming to please some of the people all of the time. People who buy Klipschorns fall in that category, as do tube amp buyers. 

Consider that all speakers suffer from fall-off, but you want to design a self-powered full-range speaker and the opportunity exists to tweak the amp to make the speaker play flat in an anechoic chamber, or else EQ needs to be applied to an amp that is technically flat. I would prefer the amp be tweaked to make the speaker play flat, rather than to have to apply EQ to the source signal to get it to play flat through the speaker. I'd prefer the bias be built into the solid-state electronics, so that the overall system benefits. I suspect this is the source of much of the elusive 'synergy' that gets written about when high-end gear is discussed.

Despite the tested 'inferiority' of tube amps, the subjective impression of many experts is they can be more faithful to how high frequencies are rendered and heard by the human ear in a live environment. Just as an 'accurate' photograph often fails to look 'authentic' because color temperature is an intrinsic aspect of the visual experience, so it is with sound. More people tend to prefer warm vs. cold - see how many black and white images wind up with sepia tone vs. selenium tonality. Even 'neutral' black is argued about because it comes in many flavors.




Sonnie said:


> My question would be... what is "right"? If there is a difference that can be heard... is it an improvement in the sound? If so, how is it improved upon and to what extent?
> 
> If the builder of the amp says I want this amp to sound different from the "typical" solid state amp... i*s he changing the sound to what "he" likes or to a sound that would be considered an improvement to anyone listening?*
> 
> FOR ME (I certainly cannot speak for everyone)... I think the entire point of making an amp sound different would be to improve the sound to a level it would be worth me paying more for it.


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## Sonnie

That would be implementing equalization into the amp. Yet, an amp should not necessarily need tweaking (equalization) in an anechoic chamber to be accurate should it? Nor are our listening rooms anywhere close to anechoic for most of us. I suppose there might be a few who have such rooms for listening.


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## Dub King

It all depends on whether you are taking a systematic approach. Building a speaker that plays perfectly flat off an amp that plays perfectly flat is incredibly difficult, and achieving that in an anechoic chamber does not necessarily translate to real-word awesomeness; well, it probably does but...

I know DSP EQ is incredibly resolute - enough to make what I am suggesting a pure hypothetical... but a systematic approach to achieving flat, neutral response from an amp/speaker combo _could_ in theory involve tweaking the amplifier to achieve the effect. Then there's the issue of the 'house curve' and whether more people prefer it vs. true flat EQ. 



Sonnie said:


> That would be implementing equalization into the amp. *Yet, an amp should not necessarily need tweaking (equalization) in an anechoic chamber to be accurate should it?* Nor are our listening rooms anywhere close to anechoic for most of us. I suppose there might be a few who have such rooms for listening.


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## Gregr

Maybe I'm simply deprived of really good music but my Toslink interconnect is sounding pretty good to me today in fact exceptional. This could be the day I need to replace the toslink with my 75 ohm copper interconnect and hope I "do not" hear any difference. That's turning everything on its head. For any of you interested hearing about the result I'll let you know.


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## Savjac

I am confused about why someone would not trust the Stereophile writers. Gordon Holt, Larry Archibald and Dick Olsher are indeed paid professionals, that tend to write what they hear and/or do not hear. The same can be said for Peter Aczel and Tom Nousaine who were also paid professionals that were said to be writing about what they hear and/or do not hear. I am curious what constitutes a difference. 

Remember, for the longest time, Stereophile and later the magazine that followed the path Gordon Hold led with, TAS, did not even accept advertisements for worry that the public would feel advertising dollars would taint their reviews. This changed when the cost of providing a glossy publication, on time, became quite expensive and could not be covered by subscription alone.


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## Dub King

I have no idea if that's sarcasm or not. For sound I actually prefer Toslink because I have pro amps in my system and I find HDMI is a direct conduit for ground loop hum coming from my cable line - a problem that is 100% avoided by connecting my TV and my HTPC to the AVR with TOSLINK instead of running video through the AVR via HDMI or digital sound through copper.



Gregr said:


> Maybe I'm simply deprived of really good music but my Toslink interconnect is sounding pretty good to me today in fact exceptional. This could be the day I need to replace the toslink with my 75 ohm copper interconnect and hope I "do not" hear any difference. That's turning everything on its head. For any of you interested hearing about the result I'll let you know.


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## Savjac

Sonnie said:


> My question would be... what is "right"? If there is a difference that can be heard... is it an improvement in the sound? If so, how is it improved upon and to what extent?
> 
> If the builder of the amp says I want this amp to sound different from the "typical" solid state amp... is he changing the sound to what "he" likes or to a sound that would be considered an improvement to anyone listening?
> 
> FOR ME (I certainly cannot speak for everyone)... I think the entire point of making an amp sound different would be to improve the sound to a level it would be worth me paying more for it.


Yep this is maybe the crux of the discussion here. Personally a difference that can be heard is not necessarily an improvement in sound. That will depend on the listener and thereby would indicate that the listener can in fact hear a difference. Again, the difference may make things worse and not better to any given listener.

There is not really a straight wire with gain as there is no perfect signal. Few of us can actually say that we know what the original sound of the recording being used for playback actually sounds like. This is especially true today when so many programs are being used in the digital domain to alter the sound of whatever is being recorded. I have never been to Abbey Road studios and have not heard The Beatles playing live into a tape recorder so I can only guess at what the sound should be like, straight wire with gain or not. 

It would seem that when listening we all use our personal abilities, tastes ane experiences to use in determining what is correct, better, worse or as per this discussion, just plain different. It has been shown repeatedly that most professional musicians have equipment that would not be considered high end as they fill in what ever may be missing or different with the way the actual music sounds with their pattern of experience. This difference in what they listen for may not be scientifically quantified but it is real.


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## Savjac

Dub King said:


> I have no idea if that's sarcasm or not. For sound I actually prefer Toslink because I have pro amps in my system and I find HDMI is a direct conduit for ground loop hum coming from my cable line - a problem that is 100% avoided by connecting my TV and my HTPC to the AVR with TOSLINK instead of running video through the AVR via HDMI or digital sound through copper.


I do not think Greg is speaking to HDMI cable but rather 75ohm coaxial cable as in spdif. I guess I should not answer something directed to someone else but that is how I read it. As a matter of course, I personally cannot reliably tell the difference between toslink and coaxial with the exception of an older monster cable I had, it just gave itself away in moments. I should take it apart to see if there is anything wrong inside.


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## Sonnie

Savjac said:


> I am confused about why someone would not trust the Stereophile writers. Gordon Holt, Larry Archibald and Dick Olsher are indeed paid professionals, that tend to write what they hear and/or do not hear. The same can be said for Peter Aczel and Tom Nousaine who were also paid professionals that were said to be writing about what they hear and/or do not hear. I am curious what constitutes a difference.


The only differences I am seeing right now is that those claiming to hear a difference have not been able to prove it with testing, while those claiming there is no difference (and even some who claimed there is a difference) have proven there is none with testing.

I have heard of quite a few people changing their belief that they can hear a difference to a confirmation that they cannot through testing... yet none that have claimed that they cannot hear to difference to a belief that they can through testing. :huh:

Just an observation... not a mandate.

Have... or would Gordon Holt, Larry Archibald and Dick Olsher submit to a DBT? I have a sneaky suspicion that it would be rather interesting. 



Savjac said:


> Remember, for the longest time, Stereophile and later the magazine that followed the path Gordon Hold led with, TAS, did not even accept advertisements for worry that the public would feel advertising dollars would taint their reviews. This changed when the cost of providing a glossy publication, on time, became quite expensive and could not be covered by subscription alone.


I don't see where this proves anything. I wonder how much of that equipment they got to keep? We do reviews and I know our reviewers have either been able to keep quite a bit of equipment and/or purchase it at ridiculously low prices. Of course we are not testing $15,000 amps either, but we have tested some high dollar gear.


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## Dub King

What I mean was that any conductive connection - SPDIF or HDMI - can make one's system vulnerable to ground loop hum if one's cable line is shoddy (like mine) and although filters exist the benefit I found from fiber optic is that it does not transfer any dirty noise. Same goes for the HTPC - the Crown picks up the faintest static that fluctuates with the hard drive's operation when the connection is HDMI.

I hate the idea that the noise is there to begin with, even if it does not affect the AVR, it goes right through and into the Crown amps where it is audible - I have an XTi-1000 dedicated to my center channel as well as an XTi-2002 running my subs... so isolating my AVR from it that hum by eliminating conductive connections makes me happy.



Savjac said:


> I do not think Greg is speaking to HDMI cable but rather 75ohm coaxial cable as in spdif. I guess I should not answer something directed to someone else but that is how I read it. As a matter of course, I personally cannot reliably tell the difference between toslink and coaxial with the exception of an older monster cable I had, it just gave itself away in moments. I should take it apart to see if there is anything wrong inside.


----------



## lcaillo

Strictly speaking, you don't prove a null hypothesis (that there are no differences). You can fail to find that there are statistically significant differences. Or your evidence may support the hypothesis that there are differences that are more likely than chance by some margin.


----------



## J&D

Dub King said:


> If solid state always sounds like solid state, then that's 'standard solid state sound', just sayin'.
> 
> If a solid state amp can be made to sound like a tube amp, then it will sound different from 'solid state sound'... but it will still be solid state. I think this has been established.
> 
> Therefore, there is a 'solid state sound' and it represents a standard - which I already identified as being flat and neutral, i.e. the hypothetical speaker cable with gain. The design goal is for these amps to sound the same. Clearly a successful endeavor as there are many amps out there which are in fact indistinguishable from each other. In fact, they 'define' the solid state category.
> 
> As for Bob Carver staying away from the concept... I really do wonder if you read what you are discussing. the very next paragraph:
> 
> _"Secondly, Bob had never before had a chance to listen critically to a "world-class" amplifier like the one we chose as our reference, and ended up admitting that there were things about its sound that he preferred to his own amp. He might, he averred, "do some things differently in future designs."_
> 
> Indeed he did, since Bob ran home with his tweaked amp and tried to clone it and sell the result.


I get where you are coming from in that solid state amps have the ability to add gain without distortion which I think is a better description than saying they have a certain sound. I just think most of the characterizations of solid state amps that continue on today are those that the tube camp applied to discredit and minimize their true performance capabilities and application in a "high end" setup. 

It is really hard to put Bob's characterization of the reference amplifier into perspective as we have no idea what it was. Again, it could have been a tube amp which offered the sound qualities he preferred and the entire test would then be better labelled as - "Can a solid state amp be made to sound like a reference tube amp?" Why yes you can, if you are Bob Carver.


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## Dub King

Footnote 3: _I believe it appropriate nearly a quarter-century later to identify the reference amplifier as a Conrad-Johnson Premier Four.—John Atkinson_

So there you go, tube amp. I must confess, I wish they had chosen a Mark Levinson or a Krell.




J&D said:


> I get where you are coming from in that solid state amps have the ability to add gain without distortion which I think is a better description than saying they have a certain sound. I just think most of the characterizations of solid state amps that continue on today are those that the tube camp applied to discredit and minimize their true performance capabilities and application in a "high end" setup.
> 
> It is really hard to put Bob's characterization of the reference amplifier into perspective as we have no idea what it was. Again, it could have been a tube amp which offered the sound qualities he preferred and the entire test would then be better labelled as - "Can a solid state amp be made to sound like a reference tube amp?" Why yes you can, if you are Bob Carver.


----------



## J&D

Savjac said:


> There is not really a straight wire with gain as there is no perfect signal. Few of us can actually say that we know what the original sound of the recording being used for playback actually sounds like.


This is exactly what solid state amplifiers are designed to do and have been doing for many years. The only issues are with poor designs or implementations of the technology along with improper use. The only disagreement is if there are any audible differences between solid state amps that are properly designed and well implemented - the majority of products available today. Can you actually hear the difference between two amps one with .01% and the other with .001% distortion?


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## Dub King

I join the 'No' camp as a direct result of my own arguments, which ultimately subverted the notion that a modern, properly designed power amp would be anything but neutral so as to provide a blank slate upon which to EQ and process sound to one's satisfaction; unless the amp is advertised as providing 'pleasing' distortion and provide controls for adding it - namely Guitar/Bass amps. If the Stereophile challenge had been about solid-state vs. solid-state I'd still debate but now it's too late.

Great discussion.



J&D said:


> This is exactly what solid state amplifiers are designed to do and have been doing for many years. The only issues are with poor designs or implementations of the technology along with improper use. The only disagreement is if there are any audible differences between solid state amps that are properly designed and well implemented - the majority of products available today. Can you actually hear the difference between two amps one with .01% and the other with .001% distortion?


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## JerryLove

Sonnie said:


> That would be implementing equalization into the amp.


Exactly: which is a great and wonderful thing in music production; but not so much in reproduction.

In reproduction it's extremely dangerous (at least at something as unconfigureable as the amp). You like "bright" so you buy a "bright" amp, but then the guy that mixes that new CD likes "bright" too, and they combine to become harsh.

It also turns a relatively simple matter of matching components into some sort of cooking recipe (I like those speakers, but with this amp, not that one: that one goes with those other speakers).

And it doesn't stop with amps. Wires *can* be made to affect sound. You would do it with DACs and preamps as well; and then getting any two components to do what you want becomes unlikely. (not to mention that there are so many variables that can be tweaked; that the likelyhood that someone tweaks the ones you want without also getting ones you don't is low).

Or: you can go flat everywhere possible, realizing that the speakers will be a compromise no matter what, and then adjust your sound with a DSP or equalizer.

An amp performing reproduction should reproduce the signal its fed. That's its job. If you want an eq, get an eq.


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## Dub King

Jerry, much better stated than our previous attempts to hash this out, I would say. What you and I are opposed to is the funny games played by the so called ultra high end folks, the ones who buy expensive fuses and hear a difference when they reverse polarity. I remember when I first started getting into pro gear I could not believe how flexible it was, how much value it offered. I used to want to own Krell, now I own Crown. As for the Pioneer receiver I became so defensive about: for the unit I bought, Pioneer did not change the amps, they did raise the price and they changed the spec to 4 ohms. It seems they under rated the sc-55 so now the sc-67 Sports the exact same specs down to the hundredth of a pound in terms of how much it weighs, and down to the walk in terms of power draw from the wall. Shenanigans, and marketing. also, it does appear that the older Crown XTi units did have issues with high frequencies due to the master clock rate driving the digital amp. That has been doubled in the new series, eliminating any such issues. I will go ahead and attribute the harsh highs on the Sony receiver I traded in to cheapness, even if some reviewers did not seem to agree and thought it a step up from my previous Sony receiver.


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## J&D

Dub King,
Those mains of yours look very interesting and I am guessing can create some impressive SPL numbers. Do you produce your own dubstep? 

Sorry about the OT post so I will edit to add this about Pioneer. I have no real experience with Pioneer amps specifically but I wonder if in your case some of the performance you are getting from your current setup over the Sony is from the pre-amp section. I did an AVR comparison a couple of years back when looking for a replacement for the UMC-1 pre-pro I purchased. I believe I tried the SC-27 against the current Onkyo and Denon AVR's at the time but only as pre-pro's because I have my own outboard amps. I have to say that I did prefer the Pioneer over the Onkyo, Denon and UMC-1 as a pre-pro. It definitely sounded the best in my system at the time. I ultimately chose the Denon 3311 over the Pio primarily for features and the differences in sound to me were slight but they were there.

JD


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## JerryLove

When I first got my 801 S2's they were very harsh. I couldn't understand why. 

I replaced the AVR I was powering them with with a Yamaha P5000S and the problem was resolved immediately.

Because of that I tried, well, almost every amp I had. I found that some could not drive the 801 S2's without being harsh (the AVRs), and others could (the dedicated amps).

I cannot tell you if it's current issues or dealing with weird impedance slopes or what: but it was clear that some were insufficient to the task. I do wish that I could quantify what the actual source of the insufficiency was.


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## robbo266317

JerryLove said:


> When I first got my 801 S2's they were very harsh. I couldn't understand why.
> 
> I replaced the AVR I was powering them with with a Yamaha P5000S and the problem was resolved immediately.
> 
> Because of that I tried, well, almost every amp I had. I found that some could not drive the 801 S2's without being harsh (the AVRs), and others could (the dedicated amps).
> 
> I cannot tell you if it's current issues or dealing with weird impedance slopes or what: but it was clear that some were insufficient to the task. I do wish that I could quantify what the actual source of the insufficiency was.


With all the design and testing equipment available today it is astonishing that there are still speakers that present a difficult load for an amplifier. 
I cannot think of any reason why they should still be doing this apart from them saving a small amount on each speaker.


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## Dub King

Jerry, in that sense the Pioneer stands alone being a class D design. The AVR that failed, almost certainly all A/B designs with an insufficient power supply. By no means does it guarantee it could drive those speakers, but at least it is fundamentally different than most receiver's amplifiers. That said, maybe it's time I get myself an EP-4000 for my mains. Current is king.


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## Dub King

It could very well be that it's the preamps. I should have run an analog direct input to both AVRs before making a judgement. The Sony is gone, so too late.



J&D said:


> Dub King,
> Those mains of yours look very interesting and I am guessing can create some impressive SPL numbers. Do you produce your own dubstep?
> 
> Sorry about the OT post so I will edit to add this about Pioneer. I have no real experience with Pioneer amps specifically but I wonder if in your case some of the performance you are getting from your current setup over the Sony is from the pre-amp section. I did an AVR comparison a couple of years back when looking for a replacement for the UMC-1 pre-pro I purchased. I believe I tried the SC-27 against the current Onkyo and Denon AVR's at the time but only as pre-pro's because I have my own outboard amps. I have to say that I did prefer the Pioneer over the Onkyo, Denon and UMC-1 as a pre-pro. It definitely sounded the best in my system at the time. I ultimately chose the Denon 3311 over the Pio primarily for features and the differences in sound to me were slight but they were there.
> 
> JD


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## lcaillo

Dub King said:


> Current is king.


LOL. So true. This sentence, along with the reference to "wire with gain" makes me recall the description of an amplifier as a "modulated power supply."


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## Savjac

Ok, I think this little fact will indeed sway everyone to my side of the fence and may induce a new poll to be launched. Are you sitting down before reading this un refutable discussion stopper ?
Here goes, I know for a fact that after a substantial amount of searching, exhausting comparative listening sessions while traveling across this great land of ours, the great romance novel cover model, Fabio bought Krell amplifiers to power his Martin Logan speakers.

Now that is a development most of you probably did not see coming and if that does not change your mind than I am at a loss for words. 

I shall now head to the nearest safe corner of my room and wait for the flack to clear. :rofl:


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## J&D

Jack,
Nice one! You got me!  Now that you mention it I think I remember seeing that very same system you are describing. It was on Fabio's appearance of _Lifestyles of the Rich and Famous_ with Robin Leach!!


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## Sonnie

Well that does it for me because I own ML's and only want the best sound they can produce. 

Krell... here I come!


*DO NOT OPEN... DO NOT CLICK THIS BUTTON! >>>>>* 



NOT!


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## Gregr

My apologies for the more cryptic posts I blurt out from time to time. I have back injuries that cause chronic pain and the medication I take for pain interferes with concentration and memory. Then too often I do not proof read my posts before putting them up for you to read. Some are not as helpful as I had hoped.


The post about swapping out my toslink with 75 ohm copper is more about the psychology of changing equipment and the expectations we/I have or the belief one is better than the other or we/I can hear a difference.


If your Toslink sounds great to you, I say you are one of the lucky ones; you have put together a system that works for you. I do not believe this is a right or wrong/bad or good kind of hobby. It is what it is. For me I find if I listen to any system long enough I go through a full range of emotions and beliefs about SQ. 


So I am thinking if I swap out my cables at a time out of the ordinary e.g. swap out cables when I am loving what I am using for equipment at the time as opposed to the typical buying a new cable when I am bored with what I am listening to in hopes the change will improve SQ 


So Mark thanks, your comment helps reinforce my belief that toslink is sounding amazing right now. I wish I could explain this and duplicate this with other equipment and at other times. So to that end I am very interested in the psych of listening to music. 
Take care Gents, I hope you all have a great New Year!!


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## chrapladm

If I could only afford Krell, I would have it for all my amplifiers. But for now I will stick with my Pro Audio Crest and other manufacturers.


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## Dub King

_edit - I accidentally identified an Apogee Studio Grand as a Martin Logan. It was 20 years ago, but I remembered what they looked like, did a Google image search..._

Hah, good enough for Fabio is good enough for me! Time to go to Manhattan and look for some used fpb 600s at the second-hand stereo shops, lol. In fact it was listening to a Krell powered system when I first realized that the ultra-high-end employed a fair bit of smoke and mirrors. I was listening to Apogee/Krell and I mentioned that a bassline from a Sly & Robbie track was missing the lowest octave. He responded 'if this system isn't reproducing the bass, it doesn't exist. It must have been imaginary bass'. Today I can play reference flat to 10hz and I can say in no uncertain terms - the bass was not imaginary. Of course the system I had back then (1991) was also capable of reproducing said 'imaginary bass'. That's the day my wish to own Krell died a quiet death.

I'm not saying that the Krell/Apogee system couldn't do the trick. On that day, the setup was less impressive than my own well tuned, less expensive rig. 

So, armed with the knowledge gained from the discussion in this thread, I re-arranged my system at least two dozen times yesterday - genuine obsessive tear apart and rearrange behavior.

The end result is that the Crown XTi-1000 is back online, driving my L/R mains. If not for this thread, I would have retired it, thinking it to be flawed. It is sensitive to noise interference, enough that stray electrical noise was polluting the highs... but that was only partly the amps fault. Treating the room also means making sure there is as little interference as possible. Having fully isolated the AVR from any conductive interconnects, and having gone through the whole feed for my cable line tightening connections, I achieved a really low noise floor and whatever was affecting the highs is gone. Since I have two identical pairs of the same speakers up front, A/B testing is a piece of cake. There's no way I'd be able to pick the Pioneer Elite AVR vs. the Crown XTi-1000 in DB tests. I am thrilled with the extra headroom (+3db) the Crown buys me - and the extra power the AVR gets for the rest of the channels - it is a genuine qualitative improvement.


----------



## Savjac

Well Mr. King, that is incredibly cool actually. The discussion has caused you to get a bit closer to your system and what it will reproduce, and it appears improvements have occured that will allow you to listen more. I am happy to know that.

In follow up to the remainder of the discussion, I realize I will not change anyones mind, without proof it is not going to happen and that makes sense...why would my rantings make any difference is quite realistic. But as mentioned above, if someone can get something out of a discussion that improves what he has in house, then some good has come of all this. I did come across a bit of new information that I did not know and has apparently been put aside with age. In watching some online interviews with Bob and also Nouisane there was a test done by The Audio Critic as a blind test between the Carver amps and as SS Levinson amp. It also ended in a cannot tell the difference, but with The Audio Critic that seems to be what everyone would more or less expect. Black box and blind testing was done and here is a description I found online that shows, Carver did manage to make it work.

_*Carver caused a stir in the industry in the mid-1980s when he challenged two high-end audio magazines to give him any audio amplifier at any price, and he’d duplicate its sound in one of his lower cost (and usually much more powerful) designs. Two magazines accepted the challenge.
First, The Audio Critic chose a Mark Levinson ML-2 which Bob acoustically copied (transfer function duplication) and sold as his M1.5t amplifier (the “t” stood for transfer function modified).
In 1985, Stereophile magazine challenged Bob to copy a Conrad-Johnson Premier Five (the make and model was not named then, but revealed later) amplifier at their offices in New Mexico within 48 hours*_

I really do not like that he sold his stuff once he copied the amps, however, in reality he could have done that from his facility in Washington without the challenge...so that seems a moot issue.


----------



## Savjac

Dub King said:


> I was listening to Martin Logan/Krell and I mentioned that a bassline from a Sly & Robbie track was missing the lowest octave. He responded 'if this system isn't reproducing the bass, it doesn't exist. It must have been imaginary bass'. Today I can play reference flat to 10hz and I can say in no uncertain terms - the bass was not imaginary. Of course the system I had back then (1991) was also capable of reproducing said 'imaginary bass'. That's the day my wish to own Krell died a quiet death.


I handily doubt the Krell was the issue here as I am pretty sure back then they were all class A amps and would go to almost DC as directed. I am not sure the ML would hit anything near that low albiet with a completely down point below say 20 hz. Intersting to note that in the interview with Carver online, he was the first to be asked to make a system inclusive of subwoofer that could not only replicate an earthquake but the sound of a jet airplane as well. As such, he did create a system that could replicate the 140 db needed for a jet engine as well as the 7 hz noise needed to replicate an earthquake. He had to cheat to get notes that low so in doing he used hyrdaulics to move the speakers in and out as slow as needed. Quite an ingenius man. 

Now I am not a big Carver fan, never have owned anything he made but in watching the video and doing some online research, I find him quite the interesting gent, a physists, an engineer and an audio manufacturer and I have none of the talen to do any of that...what a bummer. :huh:


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## Dub King

Hah, I was wrong. I used a Google Image search to flash back to 1992. The offending speakers were in fact Apogee Studio Grands, which had conventional subwoofer modules under them. Definitely controversial speakers, inefficent and a tough load even when Krell powered. ML is off the hook.

I know how great Krell amps are. I would not turn one down, I'd gladly retire my Crowns for Krells, if money was no object. I did not lust after them ignorantly, I simply lost the will to spend that much on something so heavy when the rewards are so relatively minor.

Carver is a lunatic, but he's also a cool guy. Look how far we've come. Now there are DIY sub builders who can pull off the whole 140db as well as 7 hz trick using nothing but conventional subs.



Savjac said:


> *I handily doubt the Krell was the issue here as I am pretty sure back then they were all class A amps and would go to almost DC as directed. I am not sure the ML would hit anything near that low albiet with a completely down point below say 20 hz.* Intersting to note that in the interview with Carver online, he was the first to be asked to make a system inclusive of subwoofer that could not only replicate an earthquake but the sound of a jet airplane as well. As such, he did create a system that could replicate the 140 db needed for a jet engine as well as the 7 hz noise needed to replicate an earthquake. He had to cheat to get notes that low so in doing he used hyrdaulics to move the speakers in and out as slow as needed. Quite an ingenius man.
> 
> Now I am not a big Carver fan, never have owned anything he made but in watching the video and doing some online research, I find him quite the interesting gent, a physists, an engineer and an audio manufacturer and I have none of the talen to do any of that...what a bummer. :huh:


----------



## J&D

Dub King said:


> So, armed with the knowledge gained from the discussion in this thread, I re-arranged my system at least two dozen times yesterday - genuine obsessive tear apart and rearrange behavior.
> 
> The end result is that the Crown XTi-1000 is back online, driving my L/R mains. If not for this thread, I would have retired it, thinking it to be flawed. It is sensitive to noise interference, enough that stray electrical noise was polluting the highs... but that was only partly the amps fault. Treating the room also means making sure there is as little interference as possible. Having fully isolated the AVR from any conductive interconnects, and having gone through the whole feed for my cable line tightening connections, I achieved a really low noise floor and whatever was affecting the highs is gone. Since I have two identical pairs of the same speakers up front, A/B testing is a piece of cake. There's no way I'd be able to pick the Pioneer Elite AVR vs. the Crown XTi-1000 in DB tests. I am thrilled with the extra headroom (+3db) the Crown buys me - and the extra power the AVR gets for the rest of the channels - it is a genuine qualitative improvement.


That is very cool indeed. Thanks for posting your results. One more question to ask. Did you change your vote in the poll based on your results?


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## JerryLove

Savjac said:


> _*Carver caused a stir in the industry in the mid-1980s when he challenged two high-end audio magazines to give him any audio amplifier at any price, and he’d duplicate its sound in one of his lower cost (and usually much more powerful) designs. Two magazines accepted the challenge.
> First, The Audio Critic chose a Mark Levinson ML-2 which Bob acoustically copied (transfer function duplication) and sold as his M1.5t amplifier (the “t” stood for transfer function modified).
> In 1985, Stereophile magazine challenged Bob to copy a Conrad-Johnson Premier Five (the make and model was not named then, but revealed later) amplifier at their offices in New Mexico within 48 hours*_


(of note: no testing was done blind in that case).

What carver did was invert one amp and then sum the signal (with false identical loads). He got the summed signal to flat (within -70db) by modifying his amp (supposedly: this was all behind closed doors).

The first time they listened, they though there were differences. The second time, they thought more differences. The third time they could not tell them apart.

Which is confusing because I'm not aware that it would be possible to make any changes after the first set based on the testing method used to conform the changes in the first place. -70 is -70. Perhaps there's more he didn't tell, but since that testing was the point he was trying to prove...


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## Dub King

I was not aware that I could change the vote, I will if I can.



J&D said:


> That is very cool indeed. Thanks for posting your results. * One more question to ask. Did you change your vote in the poll based on your results*?


----------



## J&D

JerryLove said:


> (of note: no testing was done blind in that case).
> 
> What carver did was invert one amp and then sum the signal (with false identical loads). He got the summed signal to flat (within -70db) by modifying his amp (supposedly: this was all behind closed doors).
> 
> The first time they listened, they though there were differences. The second time, they thought more differences. The third time they could not tell them apart.
> 
> Which is confusing because I'm not aware that it would be possible to make any changes after the first set based on the testing method used to conform the changes in the first place. -70 is -70. Perhaps there's more he didn't tell, but since that testing was the point he was trying to prove...


Or perhaps he did not change anything. :unbelievable: That would surely be a devious thing to do but sure is fun. :devil:


----------



## Savjac

JerryLove said:


> (of note: no testing was done blind in that case).
> 
> What carver did was invert one amp and then sum the signal (with false identical loads). He got the summed signal to flat (within -70db) by modifying his amp (supposedly: this was all behind closed doors).
> 
> The first time they listened, they though there were differences. The second time, they thought more differences. The third time they could not tell them apart.
> 
> Which is confusing because I'm not aware that it would be possible to make any changes after the first set based on the testing method used to conform the changes in the first place. -70 is -70. Perhaps there's more he didn't tell, but since that testing was the point he was trying to prove...


According to the article there was blind testing in the Audio Critic case. And it is my belief that he met the challenge, irrespective of his methods and therein lies the win. Yes in the case of the second test he did take time and made many changes, but that seems to have been done within the rules of the test. Accordingly, the challenge was met and there is proof in both tests that one can change the sound of an amplifier and apparently market that change which supports the proposition that one can hear the differences in amplifiers. Again, not that it will make any difference in opinions held, but appears to be proof equal to the articles posted at the beginning of this thread.

One of the coolest parts of this journey of seeking out opinions was watching Tom discuss his home systems and some of his beliefs. He really has no interest in amplification and uses self powered speakers which may not be a bad idea. Although his preamp of choice is not a cheap one by any means. None the less, he is not a guy I could hang with and not because of his beliefs but because of the way he tends to shout people down verbally when they discuss something not amplifier related. Kind of a rude guy it would seem and one that would not make it on this forum based on his comments.


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## Savjac

J&D said:


> Or perhaps he did not change anything. :unbelievable: That would surely be a devious thing to do but sure is fun. :devil:



:rofl::rofl: I had not even thought of that, would that not have been cool ??
In the video interview he did mention that changes were made but was not specific as to what those changes were.


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## Savjac

Dub King said:


> I was not aware that I could change the vote, I will if I can.


No No, I need someone on my side. No one else is speaking irrespective of the vote being so close, so no change backs allowed. I need some time to work on your. :heehee:


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## Dub King

Lol, I'm still in agreement that we clearly established amps can and do sound different from each other.

The issue is that bias needs to be 'dialed in', otherwise any competent engineer who aims for flat response with no distortion and ample power is going to produce an amplifier that sounds 'transparent' - the 'black box' from page one. Especially with modern circuits and testing equipment... it's not longer a guessing game like it was in the 1980s. It would be impossible to succeed in DB testing between two different amps that shared the same design goal of neutral, flat response. I totally get that now. If there is something making one amp sound 'different' the chances the cause is external seems much more likely.

The fact that amplifiers can be designed with a signature sound is still relevant to pre-amps, that's where such 'tweaks' belong... not in the main amplifiers.



Savjac said:


> No No, I need someone on my side. No one else is speaking irrespective of the vote being so close, so no change backs allowed. I need some time to work on your. :heehee:


----------



## 3dbinCanada

The only time amps sonic signatures differ from one another is when they are being pushed well beyond their output capabilities. If the power draw is well within the weakest amp in a comparison, then there will be no audable differences. I am assuming competently designed amps whichh would exclude boom boxes and things of that ilk.


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## JerryLove

Mark, I could not agree with you more.


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## J&D

Dub King said:


> Lol, I'm still in agreement that we clearly established amps can and do sound different from each other.
> 
> The issue is that bias needs to be 'dialed in', otherwise any competent engineer who aims for flat response with no distortion and ample power is going to produce an amplifier that sounds 'transparent' - the 'black box' from page one. Especially with modern circuits and testing equipment... it's not longer a guessing game like it was in the 1980s. It would be impossible to succeed in DB testing between two different amps that shared the same design goal of neutral, flat response. I totally get that now. If there is something making one amp sound 'different' the chances the cause is external seems much more likely.
> 
> The fact that amplifiers can be designed with a signature sound is still relevant to pre-amps, that's where such 'tweaks' belong... not in the main amplifiers.


Very well stated and sums up many of the opinions given here. That is also why some might use a tube pre with a solid state amp. As I stated before I am not in favor of doctoring an SS amp to try to make it sound like a tube amp as you would almost always fall short of the tube camps expectations while also alienating those that want a solid state amp with a silent and flat response.


----------



## J&D

Savjac said:


> :rofl::rofl: I had not even thought of that, would that not have been cool ??
> In the video interview he did mention that changes were made but was not specific as to what those changes were.


I previously posted some of the shenanigans I played on unsuspecting victims and it was all in fun. A couple of the most difficult personalities that participated in the blind test but refuted the results in any way they could also subjected themselves to another test where I was responsible for moving the connections manually as they did not like the fact that there was a switch inserted in the blind test. I purposefully did not move the connections at all and left my amplifier connected the entire time. The comments regarding how my amp sounded did in fact change when they thought it was the reference amp they were listening to!! 

It was very surprising to me that neither of these gents could pick out the fact that I had not changed the amp at all. The Carver test at least in the case of the tube amp comparison makes sense that he actually needed to modify his amp to match the characteristic harmonic distortion of the reference amp.


----------



## Savjac

J&D said:


> I previously posted some of the shenanigans I played on unsuspecting victims and it was all in fun. A couple of the most difficult personalities that participated in the blind test but refuted the results in any way they could also subjected themselves to another test where I was responsible for moving the connections manually as they did not like the fact that there was a switch inserted in the blind test. I purposefully did not move the connections at all and left my amplifier connected the entire time. The comments regarding how my amp sounded did in fact change when they thought it was the reference amp they were listening to!!
> 
> It was very surprising to me that neither of these gents could pick out the fact that I had not changed the amp at all. The Carver test at least in the case of the tube amp comparison makes sense that he actually needed to modify his amp to match the characteristic harmonic distortion of the reference amp.


Of course I would never advocate fooling someone like this :innocent:, however, the end result seems to be that the mind is a terrible thing to use. This would be a bit embarrassing to be sure even if someone volunteered for the testing knowing going in that differences would have to be noted.


----------



## Dub King

Considering the fact our eyes can be fooled this easily: 










It's not a surprise one can also fool the ears with ease.


----------



## primetimeguy

^^^^

exactly my point, the brain is way to easily fooled. It isn't easy setting up and conducting a valid test.


----------



## sub_crazy

primetimeguy said:


> ^^^^
> 
> exactly my point, the brain is way to easily fooled. It isn't easy setting up and conducting a valid test.


But is it fooled into believing there is a difference or there isn't ? onder: 

I can't this debate is still going on, there is no right or wrong answer that anyone on either side of the argument will agree on. I am dizzy from running around in circles :run2::run:


----------



## sub_crazy

Dub King said:


> Considering the fact our eyes can be fooled this easily:


That thing is weirding me out!


----------



## JerryLove

I thought it might be better with just one eye.

...


It's not.


----------



## JerryLove

sub_crazy said:


> But is it fooled into believing there is a difference of there isn't ? onder:


There is no difference between the background (or letter) colors in square A and square B


----------



## lcaillo

primetimeguy said:


> ^^^^
> 
> exactly my point, the brain is way to easily fooled. It isn't easy setting up and conducting a valid test.


It is even harder to recognize when we are being fooled, or when our biases affect our perception. The correct answer...nearly always.


----------



## sub_crazy

JerryLove said:


> There is no difference between the background (or letter) colors in square A and square B


I had to look that one up, I was perplexed to say the least.










I am still scratching my head over that one though, was this puzzle made by Dan D'Agostino, formerly of Krell? :bigsmile:


----------



## Dub King

That 'illusion' is taught in 2D design 101. It's very important for their careers that graphic designers, interior decorators and of course painters understand these issues.



sub_crazy said:


> I had to look that one up, I was perplexed to say the least.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I am still scratching my head over that one though, was this puzzle made by Dan D'Agostino, formerly of Krell? :bigsmile:


----------



## sub_crazy

So what's the lesson? Is it shading or the presence of the green cylinder?


----------



## Dub King

It's entirely in the shading and how your eye compensates. You've seen the illusion with the black and white grid, where phantom gray dots appear - that's what's going on. The green has nothing to do with it.












sub_crazy said:


> So what's the lesson? Is it shading or the presence of the green cylinder?


----------



## sub_crazy

Very interesting. Thanks Mark!


----------



## chrapladm

So amps do sound differently because of shading?  J/K

With so much affecting the signal chain and purist always wanting to limit what goes in the signal chain I would have to agree that some amps can change the sound of any original input signal.

I am dizzy now from all this foolish imagery.:rofl:


----------



## Dub King

Suffice to say, the method by which one's brain takes what's coming in through the ears as cobbles together the illusion that there is a musician standing in the space between their two speakers is dependent on a similar mechanism.

For the sake of sticking with sound, here' the 'Shepard Tone' audio illusion - the 'endless gliss'

http://youtu.be/iupWWsh8YCo



chrapladm said:


> So amps do sound differently because of shading?  J/K
> 
> With so much affecting the signal chain and purist always wanting to limit what goes in the signal chain I would have to agree that some amps can change the sound of any original input signal.
> 
> *I am dizzy now from all this foolish imagery*.:rofl:


----------



## Savjac

I was not able to grasp the thought of imaging early on in my quest for sound that brought me closer to the music, performers and what was trying to be reproduced. I now very much believe in imaging, the formation of a volatile sound space between, behind and outside of the speaker plane. 
The down side of knowing this is available but some pieces of equipment will not replicate the illusion. That has allowed me to on occasion easily know that some amps do not reproduce this as easily as others. And no it is not indigenous to amp, cd players, dacs, preamps and some speakers can drain the sound space from the room in a heartbeat.


----------



## chrapladm

My quest for finally hearing a "live recording," sound like a live recording was when I heard a Yamaha baby grand piano connected to one of ML's bigger ESL speakers. It was playing a SACD with classical jazz. Was just amazing. Unfortunately that is only one particular genre.

I like the fact that I could build my own amplifier, tone characteristic and all built in. But with all the music I listen to and so much of the music industry being electronic instruments I am liking the pro audio amps consistency of sounding similar.


----------



## 3dbinCanada

Savjac said:


> I was not able to grasp the thought of imaging early on in my quest for sound that brought me closer to the music, performers and what was trying to be reproduced. I now very much believe in imaging, the formation of a volatile sound space between, behind and outside of the speaker plane.
> The down side of knowing this is available but some pieces of equipment will not replicate the illusion. That has allowed me to on occasion easily know that some amps do not reproduce this as easily as others. And no it is not indigenous to amp, cd players, dacs, preamps and some speakers can drain the sound space from the room in a heartbeat.


:unbelievable:

I find it odd that people place imaging qualities on their electronics and not so much on speakers/room acoustics where it should be. If the imaging is poor, change out the speakers, fix the acoustic space the speakers are located in before driving over the electronics cliff of no value added.


----------



## Savjac

Maybe I was not clear and frankly that seems to be happening a lot these days. Yes Speakers must be able to do this first and foremost and they have the largest portion of the responsibility in the creation of the soundspace. However, what I mean to say is that other components in the chain of reproduction, including the original medium be it cd, vinyl, tape of computer. Each piece has to work together to make this happen. When it works, dang it is a very nice experience for a 2 channel stereo.


----------



## Savjac

chrapladm said:


> My quest for finally hearing a "live recording," sound like a live recording was when I heard a Yamaha baby grand piano connected to one of ML's bigger ESL speakers. It was playing a SACD with classical jazz. Was just amazing. Unfortunately that is only one particular genre.
> 
> I like the fact that I could build my own amplifier, tone characteristic and all built in. But with all the music I listen to and so much of the music industry being electronic instruments I am liking the pro audio amps consistency of sounding similar.



I have to admit to ignorance in this case, I have used pro amps when playing in the band, I have a big ole pro amp in the garage wrapped up, but have never used on or heard one in a home stereo. 

I know I know, but I always had a mind set that they were not up to home audio standards in way of sonic attributes. Me thinks I may have to get some adapters and try this out one day, although that could shatter a long held belief. Oh the horror......:yikes:


----------



## J&D

Jack - you have been holding out on us. Sounds like you may have everything you need to conduct your own blind A/B testing. Just enlist a friend to do the swaps or get a simple A/B switch. I would volunteer but fear I have eliminated myself from the possible pool of candidates.


----------



## chrapladm

Savjac said:


> I have to admit to ignorance in this case, I have used pro amps when playing in the band, I have a big ole pro amp in the garage wrapped up, but have never used on or heard one in a home stereo.
> 
> I know I know, but I always had a mind set that they were not up to home audio standards in way of sonic attributes. Me thinks I may have to get some adapters and try this out one day, although that could shatter a long held belief. Oh the horror......:yikes:


Definitely must try. With my budget line array I was powering with only 100 watts and they sounded pretty good. Then with my power amp in bridged mode powering the line array things really really sounded good. Huge difference and definitely sold me on having way more wattage on everything I have. Line array is only about 120watts rms speaker. Put 3000watts to it and keep volumes sain and this speaker really shines. Amazing. So yes you must try it.


----------



## Savjac

Not sure it will do me any good as I just opened the bubble wrap and it is a Peavey 2.6C and the front panel is stamped with 130 Watts per channel in stereo, which is much less than the Emo's in the system now. None the less, it cant hurt to get the proper adapters and float it in the system one day soon. I could pull the B&W's out of storage and move the Martin Logans aside for a night. Could be fun to just mess with stuff.


----------



## chrapladm

Either way you never know until you try. I dont think anyone should go out and buy a power amp just to try it. Just use what you can and see if you like is all. Then you can A/B the amplifiers to see which amps tone you like.


----------



## madbrayniak

I voted yes but I dont neccesarily believe that it is a "significant" different. In my studies of amplifier design which I have been doing in my free time there has been much discussion in my books about 2nd and 3rd order Harmonic Distortion and how the 2nd order sounds more pleasing to us than 3rd order distortion. 

Because of this I believe it is possible that you can hear a difference as a amplifier of 2nd order harmonic distorition of say 10%(I know this is really high) compared to one with 10% of 3rd order distortion...the majority would take the former as their choice.

Now I know some of you will bring tube amps up because they have a higher 2nd order distortion and I think that is why so many find them to sound more musical, but with the problem of Intermodular Distortion I do not believe that they will work in the majority of situations. I also find them to be a bit finnicky. I have a Bottlehead Quickie in my office and think it sounds great going to the amp and speakers....but the tubes in the Quickie are infrasonic which can be annoying and having to replace tubes with "matched" pairs gets pricey.


So I think in my amplifier studies I am going to focus more on Mosfet designs than anything else.


----------



## informel

informel said:


> To me this is exactly what happened a random result, if you flip a coin you would average 5:10, if you do the test over and over you may even get 8:10 or 2:10.
> 
> If there is an audible differnce then he should get 10:10, if he gets 8 or 9 out of 10 consistently, then I would say there is something very sutile.


Funny last week I was with a fellow worker and at lunch time he alway want to play cards, but we need to be 4 to play the game he likes, anyway he asked me to guess the color of the card he was holding and I had a score of 5 on 5, he then stopped playing probably thinking that I had some king of power.

I am sure I would have get only 2 or 3 if he had tried again, so there you go to make the test valid, you have to have a perfect score (or very close to it if the difference is very subtil) and be able to repeat that multiple time.


----------



## lcaillo

Validity of a test is whether it tests what is intended. Whether results are convincing or not depends upon how you define your statistical test and how you interpret the results. There are well established statistical means to determine whether a result represents a better than chance outcome and depends upon the number of choices and the number of trials.


----------



## AudiocRaver

Savjac said:


> I was not able to grasp the thought of imaging early on in my quest for sound that brought me closer to the music, performers and what was trying to be reproduced. I now very much believe in imaging, the formation of a volatile sound space between, behind and outside of the speaker plane.
> The down side of knowing this is available but some pieces of equipment will not replicate the illusion. That has allowed me to on occasion easily know that some amps do not reproduce this as easily as others. And no it is not indigenous to amp, cd players, dacs, preamps and some speakers can drain the sound space from the room in a heartbeat.


In my experience, imaging is the quality of a music reproduction system that contributes the most to creating the illusion of reality. When it is perfect, you get a delightful experience where the brain is confused, thinking of a vocalist, for instance, "She is right here in the room... But she can't be, it's only a recording... But it can't be a recording, it is real, she is _right there..."_

That level of perfection is rare and not easily achieved, and _startling_ when you do experience it. My own successes in getting their have involved working on speaker placement and room treatment first. I have NEVER achieved it with a "typical" or "recommended" speaker placement, and sometimes it has taken an off-axis set up which then requires EQ to get the frequency response right. My recommended approach: speaker placement for imaging, then EQ correction as needed.

This is where a speaker with flat off-axis response really shines. Check out this thread.

I have not yet run into amplifier or other componentry being an obstacle to achieving stellar imaging. Not arguing that it cannot be the case, simply stating that speakers and room seem to be 99.9% of it, in my experience.


----------



## Dub King

I am in total agreement. Desktop computer speakers can achieve impressive imaging, as can huge P.A. speakers. It's all about direct & reflected sound balance, room treatment and optimizing for the listening position - and yes, it is the most satisfying illusion when it is achieved.



AudiocRaver said:


> In my experience, imaging is the quality of a music reproduction system that contributes the most to creating the illusion of reality. When it is perfect, you get a delightful experience where the brain is confused, thinking of a vocalist, for instance, "She is right here in the room... But she can't be, it's only a recording... But it can't be a recording, it is real, she is _right there..."_
> 
> That level of perfection is rare and not easily achieved, and _startling_ when you do experience it. My own successes in getting their have involved working on speaker placement and room treatment first. I have NEVER achieved it with a "typical" or "recommended" speaker placement, and sometimes it has taken an off-axis set up which then requires EQ to get the frequency response right. My recommended approach: speaker placement for imaging, then EQ correction as needed.
> 
> This is where a speaker with flat off-axis response really shines. Check out this thread.
> 
> *I have not yet run into amplifier or other componentry being an obstacle to achieving stellar imaging.* Not arguing that it cannot be the case, simply stating that speakers and room seem to be 99.9% of it, in my experience.


----------



## TheHammer

AudiocRaver said:


> In my experience, imaging is the quality of a music reproduction system that contributes the most to creating the illusion of reality. When it is perfect, you get a delightful experience where the brain is confused, thinking of a vocalist, for instance, "She is right here in the room... But she can't be, it's only a recording... But it can't be a recording, it is real, she is right there..."
> 
> That level of perfection is rare and not easily achieved, and startling when you do experience it. My own successes in getting their have involved working on speaker placement and room treatment first. I have NEVER achieved it with a "typical" or "recommended" speaker placement, and sometimes it has taken an off-axis set up which then requires EQ to get the frequency response right. My recommended approach: speaker placement for imaging, then EQ correction as needed.
> 
> This is where a speaker with flat off-axis response really shines. Check out this thread.
> 
> I have not yet run into amplifier or other componentry being an obstacle to achieving stellar imaging. Not arguing that it cannot be the case, simply stating that speakers and room seem to be 99.9% of it, in my experience.


In my early years, I invested in (what was then) a very high quality pair of speakers. I then moved from an apartment, to a rental house, then to our first house, then to a second house, all with the same setup (amp, preamp, turntable, equalizer, and speakers). After each move, the speakers sounded totally different. The only time I had great imaging was when the room was totally symmetrical. And each time, I brought in a friend who had access to a pink noise generator and we equalized the response as best we could. That helped, but it never made up for the effect of the room and furniture.


----------



## Savjac

Im still here but have not had time nor inclination to do any swap outs. My wife has been quite ill and she takes first place for time of course. Hopefully this week I will be able to mess around.


----------



## Jungle Jack

Savjac said:


> Im still here but have not had time nor inclination to do any swap outs. My wife has been quite ill and she takes first place for time of course. Hopefully this week I will be able to mess around.


Indeed. Best wishes to your wife for a speedy recovery.


----------



## AudiocRaver

Savjac said:


> Im still here but have not had time nor inclination to do any swap outs. My wife has been quite ill and she takes first place for time of course. Hopefully this week I will be able to mess around.


We get so carried away with our fun A/V hobbies, we sometimes forget there are ARE more important things in life, starting with family. Best wishes.


----------



## Gregr

Health is a precious gift, equal only to being loved or being with somebody you love...
Best Wishes and a speedy recovery. 

I've found a simple remedy, "Rescue Remedy" has an alopathic ingredient of zinc and several homeopathic ingredients that help knock down first signs of cold or flu symptoms and also support the immune system for a faster recovery. Use this especially at first signs of cold or flue and use sparingly but daily during a cold or flu. Everybody is different but for me colds last 3-4 days and are never severe. I cannot remember when I've had a cold or flu. It was at least before collage in 92'

Regards


----------



## Savjac

Thank You gentlemen and y'all are of course correct. When loved ones are ill it shines a bright light on what is truly important in life. Thanks Greg for the advice but it is not the flu she suffers from, she has Crohns and had to have several feet of her intestines removed a good many years ago. Well this disease never quite goes away and the Sunday before last it came back with a vengeance. She is home now trying to recuperate for a bit so she can go back to the hospital and have some additional surgery.

Yes I am being a good boy for once and playing her plenty of music, and truth be told, she does not give a wit about the equipment being used, she likes the sound and that is cool. I have tried to break her in to the constant frustration of upgrades and change outs and she more or less shakes her head and gives me THAT look. :blink:


----------



## Savjac

Ok everyone that has been holding their breath can now let the bad air out and take in some fresh breaths I have done my comparison and the results are not surprising but....and this is a big question, did my initial biases that I of course do not have, influence the results ? I am not sure but I did give this a good go. Inserting the Peavey into the system was fun and a neat romp with different electronics. I did not think the Peavey sounded as good as the Emo and just did not have the same sense of drive. The pro amp just sounded somewhat less authoritative and less colorful if you will. I was just not drawn into the music in as positive a way when the Pro amp was involved. Now please note this could be due in part to the adapters that have to be inserted and the fact that the Pro was much less powerful I am just not sure, so it is quite possible they were not playing on a level field, but as it was the only Pro amp in the house, it was worth a try. Could I live with the Pro amp, yep, but I would not wish to replace anything with it at this time. 
What does this mean ?? I really do not think it means a whole lot because of the differences in everything surrounding the test. It was, I have to admit, much less of a difference than I anticipated and that thought alone causes me to explore further.


----------



## morevideoplz

My sister has crohns for 25 plus years so my prayers for both of you. Back to the amp question.One guy was right, speakers are the limiting factor , room treatment is second most important. But matching the right amp to the speakers is very important. Over my 35 years of careful listening (my system and a handful of other peoples) I have heard many tube amps which blended well with the speakers. Highend class "A" amps have done a wonderful job with the right speakers several times. Back in the early 80's there was a cheap $200 NAD intergrated amp that many people wanted for the pre-amp section which drove small speakers really well. So find the right combo , its not just spend as much as you can. Good luck , oh yea amps sound different ,listen more- its for fun......


----------



## Dub King

morevideoplz said:


> My sister has crohns for 25 plus years so my prayers for both of you. Back to the amp question.One guy was right, speakers are the limiting factor , room treatment is second most important. But matching the right amp to the speakers is very important. Over my 35 years of careful listening (my system and a handful of other peoples) I have heard many tube amps which blended well with the speakers. Highend class "A" amps have done a wonderful job with the right speakers several times. Back in the early 80's there was a cheap $200 NAD intergrated amp that many people wanted for the pre-amp section which drove small speakers really well. So find the right combo , its not just spend as much as you can. Good luck , oh yea amps sound different ,listen more- its for fun......


Best I can recall, back in the early '80s my Technics receiver did just fine running a pair of EPIs. Honestly, by the time 1980 rolled around, I already was an "audio atheist". I still believed the hype about amps sounding different, but now that I'm a grown up I know the difference between fantasy and reality. If an amp is solid state and features typical FR and THD numbers, then it sounds the same as the next amp, so on and so forth. As has been discussed already, tube amps add distortion to the signal, which amounts to a 'signature sound'... so of course tube amps do sound different from each other, and different from solid state amps.


----------



## 3dbinCanada

Amps will be sonically indistinguishable if the follow caveats are met:

- the load presented to the amps is well within the intended design paramaters of the amps
- the same load is used to test among the amps
- the room acoustics are identical and speaker/lietener position remains identical through out the tests.
- listening tests are conducted as Single Blind Listening tests. Doesn't have to be double blind tests.


----------



## Savjac

Might I suggest subscribing to the Paul McGowen news letter, he of PS Audio. He is quite clear that different topologies sound different and has proven it over the years. Interesting reading. I think that most designers do the same thing. One can find many discussions from the designers about how and why they use certain products to tailor the sound of their products. Having not designed one before I can only say that different types of components imo do sound differently. In building speakers I find that using better components in the crossover certainly did change the sound, ergo, they should do the same in any electrical component that is manipulating sound/electricity.


----------



## J&D

This article is a pretty good read. I realize it is on sampling theory and not how different amps "sound" but there is some good reference to how our ears work. I have had some fun with a couple owners of golden ears and subjecting them to blind testing. 

http://people.xiph.org/~xiphmont/demo/neil-young.html


----------



## Savjac

Paul has issued a series of articles that start from design to execution of many different components and he seems to be quite adept at what he is doing, Personally I do not take stock in blind testing as it really limits our acclimation to products that may or may not be closely familiar to us. I do understand than half the folks polled hear no difference and that is quite important. But maybe if the have that cannot hear the difference would spend more time with the products they may. Who knows. I do believe that differences have to be there if for no other reason than so many different components are used.


----------



## chashint

Savjac said:


> Might I suggest subscribing to the Paul McGowen news letter, he of PS Audio. He is quite clear that different topologies sound different and has proven it over the years. Interesting reading. I think that most designers do the same thing. One can find many discussions from the designers about how and why they use certain products to tailor the sound of their products. Having not designed one before I can only say that different types of components imo do sound differently. In building speakers I find that using better components in the crossover certainly did change the sound, ergo, they should do the same in any electrical component that is manipulating sound/electricity.





Savjac said:


> Paul has issued a series of articles that start from design to execution of many different components and he seems to be quite adept at what he is doing, Personally I do not take stock in blind testing as it really limits our acclimation to products that may or may not be closely familiar to us. I do understand than half the folks polled hear no difference and that is quite important. But maybe if the have that cannot hear the difference would spend more time with the products they may. Who knows. I do believe that differences have to be there if for no other reason than so many different components are used.


http://www.psaudio.com/product-page/ 

When you reference articles without links it really takes away the credibility of the reference.
PS Audio does not even sell amplifiers.
And of course you take no stock in blind tests because the results always discount your position.


----------



## gdstupak

From article linked to earlier...

"_Sampling rates over 48kHz are irrelevant to high fidelity audio data,...
...Because digital filters have few of the practical limitations of an analog filter, we can complete the anti-aliasing process with greater efficiency and precision digitally. The very high rate raw digital signal passes through a digital anti-aliasing filter, which has no trouble fitting a transition band into a tight space. After this further digital anti-aliasing, the extra padding samples are simply thrown away. Oversampled playback approximately works in reverse.
This means we can use low rate 44.1kHz or 48kHz audio with all the fidelity benefits of 192kHz or higher sampling (smooth frequency response, low aliasing)....
...OK, so 192kHz music files make no sense. Covered, done_." 

Is this guy saying that if I feed my system a high resolution signal (192kHz), the filters in my system will throw out most of the information, reducing it to the resolution of 44.1kHz? If this is not what he is saying could someone explain in direct layman's terms why 192 is no better than 44.1? 

I understand the author's explanation of how increased frequency range and increased dynamic range (may) not increase playback fidelity (and may even increase some distortion), but don't higher resolution signals increase fidelity in other ways, such as offering more information for the playback system to work with (I equate this to how low resolution lossy (mp3) sounds worse because less information is available, so shouldn't high resolution (192kHz/48bit) sound 'closer to the source' than standard resolution (44.1kHz/16bit) simply because it contains more information)?


----------



## J&D

Savjac said:


> Personally I do not take stock in blind testing as it really limits our acclimation to products that may or may not be closely familiar to us. I do understand than half the folks polled hear no difference and that is quite important. But maybe if the have that cannot hear the difference would spend more time with the products they may. Who knows. I do believe that differences have to be there if for no other reason than so many different components are used.


I hear what you are saying but some of my experiments included gear that the "ears" actually owned and spent a lot of time with. This did not effect the results of the test in any way. 

The power of influence our brains have is of magnitudes greater than the capability of our ears. Blind testing is the best we have at removing this massive variable from the equation. I will say that even when faced with overwhelming evidence the believers or the "ears" would point to anything that would suggest the test had to be flawed in some way. We would do everything we could to remove or mitigate that which was called out as a flaw in the testing methodology but it would never be quite enough. Further evidence, to me at least, that our brains hear these differences rather than our ears.

In the end we each want to feel good about what we have spent our hard earned cash on. The only reason I have ever gone down this path of disproval is because there are those that need to make others feel less because of the choices they have made.


----------



## lcaillo

I subscribe to Paul's newletter and have followed his carreer from the early days of PS. They made some very good products. Much of what he has written in recent years, however, makes little sense to me and is not well supported by objective measurement, at least not that he has published. I would recommend reading what he writes very critically and look for support beyond his reputation as a brilliant designer. He is also selling products and is very good at generating interest and belief.


----------



## 3dbinCanada

Savjac said:


> Might I suggest subscribing to the Paul McGowen news letter, he of PS Audio. He is quite clear that different topologies sound different and has proven it over the years. Interesting reading. I think that most designers do the same thing. One can find many discussions from the designers about how and why they use certain products to tailor the sound of their products. Having not designed one before I can only say that different types of components imo do sound differently. In building speakers I find that using better components in the crossover certainly did change the sound, ergo, they should do the same in any electrical component that is manipulating sound/electricity.


The only difference you may here are between tube and SS amps. I prefer Floyd Toole's outlook over Paul McGowen as Floyd also takes into account, sight bias which plays a major roll in human hearing perception. Its interesting that SBT testing was never mentioned in Paul's article. Just saying,.


----------



## 3dbinCanada

lcaillo said:


> I subscribe to Paul's newletter and have followed his carreer from the early days of PS. They made some very good products. Much of what he has written in recent years, however, makes little sense to me and is not well supported by objective measurement, at least not that he has published. I would recommend reading what he writes very critically and look for support beyond his reputation as a brilliant designer. He is also selling products and is very good at generating interest and belief.


Floyd Tooles work is far more objective and is supported with objective test result, not marketing gimmo speak.


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## Sonnie

This is a pretty interesting article: What We Hear


----------



## 3dbinCanada

Sonnie said:


> This is a pretty interesting article: What We Hear


I've always maintained that hearing is not only done with our ears but every other sense available to us. I'm an advocate for blind listening tests and it always weeds out the chaff from the kernel.


----------



## Savjac

Indeed an interesting article that does not explain all of the things humans can handle. There are not measurements for everything, many things in the world are still built on guesses or faith, and yet...we experience them. For all the written bluster and rhetoric, about half of the audience can still hear the differences. 
For me, it seems more obvious in that as I said before, so many designs, so many different signal paths, so many different components, it would seem close to impossible to not have a difference. Because some cannot hear the difference does not negate the difference.


----------



## Sonnie

I don't think the article was intended to explain all of the things humans can handle. 

About half the audience "claims" they can hear a difference.

We can also say that just because someone claims they can hear a difference does not mean there really is a difference. Double blind listening tests have proven to clear up any doubts for those willing to participate. Those who have participated have learned in fact that they only thought they heard a difference. I have yet to find any DBT that proved otherwise. Of course it seems that some people who claim they can hear a difference are against DBT... and for obvious reasons perhaps. :whistling:


----------



## 3dbinCanada

Savjac said:


> Indeed an interesting article that does not explain all of the things humans can handle. There are not measurements for everything, many things in the world are still built on guesses or faith, and yet...we experience them. For all the written bluster and rhetoric, about half of the audience can still hear the differences.
> For me, it seems more obvious in that as I said before, so many designs, so many different signal paths, so many different components, it would seem close to impossible to not have a difference. Because some cannot hear the difference does not negate the difference.


To me its even more obvious than it is for you as I am an electrical engineer and I know that everything that is built in audio is measureable. What I don't know is how much my other senses interfere with my hearing in forming a purely subjective opinion on what I hear. Therefore I will resort to blind listening tests that eliminate many o fteh other biases brought on by my other senses. Don't be fulled into thinking that your other senses have no play in what you hear. They do.


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## lcaillo

I agree, everything is measurable. What I will differ with most about is whether we measure all of the meaningful information.

Much off perception has nothing to do with hearing nor with the sound present at the ears. It can have much to do with what we expect to hear.


----------



## 3dbinCanada

lcaillo said:


> I agree, everything is measurable. What is will differ with most about is whether we measure all of the meaningful information.
> 
> Much off perception has nothing to do with hearing nor with the sound present at the ears. It can have much to do with what we expect to hear.


And building on your last statement, its the other senses we have that help us shape what we expect to hear.


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## Savjac

...and just over half the audience "Claims" they cannot hear the difference.
The information that the dbt test has 100% infallibility raises the biggest red flag for me and actually tells me there is something not quite right there. Very few things have 100% expectation ratio, short of the earth turning and the sun peaking out of the east every day. In my opinion there is something about the testing itself that causes the end result. 
It seems easy enough to understand where chance comes into play, but having 100% same results is just not natural.


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## Sonnie

Of course it is going to raise a red flag for some of those who will never believe they can not hear a difference. You believe you can hear a difference, and you don't want to be proven wrong, so it stands to reason you will always find fault with anything proving that you can not hear a difference, regardless if it is true or not. Yet it does not appear you will ever be able to objectively prove you can hear a difference.

Actually the tests have not been 100% that they stated they could not hear a difference, instead they could not conclusively get it right that they heard a difference 100% of the time.

I think the philosophy you use is that of there can be no truth to anything (other than the sun rising in the east, setting in the west, and the earth being round). Proving something inconclusively does not necessarily mean there is something wrong with the method in which it was inconclusively proven. 100% is certainly not a rarity and in no way suggests something is flawed, instead is assures something is indeed correct in most cases.

No one has been able to prove any fault with the DBT that have been conducted thus far. However, if someone did prove there was a fault with a DBT, they should identify the fault, resolve the issue and carry on with DBT. I am pretty sure the end result will be the same. If they could hear a difference 100% of the time, then I would suggest the DBT is flawed or there is a bad amp, or one intentionally coloring the sound.


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## Savjac

So we do admit an amp "Can" color the sound, which would be in the camp that all amps do not sound alike ? Are we to discount the "Almost" half of the respondents that can hear a difference because some others say we can't ? If we are to believe the DBT test then all colas taste alike, fresh and non fresh foods taste the same, corn feed beef tastes the same as grass fed beef, off brand and name brand veggies taste the same. These allegations are just not true. I am sure there are myriad articles on why DBT does not pose a real world offering.


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## lcaillo

Whether amps sound different or not, what is important to any one individual is whether there is any perceptible meaningful difference to that individual. That belief, opinion, or perception has little to do with whether DBTs demonstrate a reliable difference or not. We keep debating the issue from two perspectives that most on either side CHOOSE have no middle ground. 

Then there is the agnostic among us who understand that we can never prove a negative, only fail to reject a hypothesis, and BELIEVE that we have not asked the most meaningful questions for either camp. On the side that believes there is no difference between amps, we have not developed and used consistently standards that identify where the limits are where most amps exceed their design parameters in the real world. For those that believe they hear differences we have not sufficiently identified how amps differ, even where there are apparently clear differences in sound. Perhaps if we did both, both sides would find where they are correct and where they have made incorrect assumptions. It seems quite obvious that there is merit in both perspectives, and more we could do with technology to satisfy the curiosity of both.


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## Sonnie

Absolutely amps can color sound, but they would likely be inferior amps. A good reputable company is not going to allow their amp to color the sound. Their intent is to render the signal as neutral as possible. Once you get to neutral and quiet, there isn't anything left to do to the signal. If you do anything else to change it from neutral, then it won't be accurate, at least if I am understanding the claims of all the reputable amp manufacturers. For the record... go back to the original claims here... we have never EVER stated amps that color the sound could not sound different, although I suspect subtle coloration might not be audible (we could do a DBT to find out though). 

Rather than say I discount what they say, I would challenge them to prove they can hear a difference via DBT. I certainly doubt they can hear a difference based on what has been proven, but I won't completely discount their belief until we find out for sure. Maybe they can, but prove it to me... and prove it to themselves... there should be no reason not to try it. If you can still hear the differences, then you be able to describe that difference and we should all be able to hear it if it is audible.

I am not sure how we get past the fact that no one has been able to "prove" they can hear a difference, while there is ample proof that differences could not be heard, even by those who thought they heard a difference. I am not the one that caused them to not be able to hear a difference, I am simply passing on the information that is has been proven. 

So ultimately, we don't discount them because "others" say they can't hear a difference, we simply doubt that they realize they cannot hear a difference because they have not participated in a DBT. 

I have absolutely ZERO issues participating in a DBT to help be prove one way or another. I don't trust my hearing based on the proof that has been given that even the best ears in the business could not hear a difference when subjected to a DBT. That's not my fault... and it is not the fault of anyone that says they cannot hear a difference. It is simply the facts.

Btw... it has been proven over and over again in blind tests that Pepsi tastes different than Coca-Cola. The analogies you have provided are silly and give no support to the discussion. No one is suggesting we cannot tell the difference between any and everything... that is just plain silly. We are talking specifically about good quality amps.


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## kingpin748

So when when people say all amps sound the same are they saying that if I compare a Yamaha RXV1073 to a Denon 4520 I should be able to tell them apart? I sold my Denon 3311 on a Thursday expecting my 4520 to show up on the Friday which it didn't. Taking pity on me my hi-fi guy gave me a Yamaha to take home for the weekend. I plugged it into my 7.1 system and I immediately noticed a difference or at least I think I did. Now at the time I wasn't even thinking different sound but as soon as I put in a movie it just seemed different. I would have to say it sounded brighter. When I got the 4520 on Monday everything seemed to go back to normal. Normal with a plethora of new features, zones, and a sub eq.

For the record I'm a Monoprice guy and consider $700 power cords and $1200 speakers wires an amazing waste of money. 

Loved the article and fully agree with it.


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## lcaillo

There are many variables that could account for an actual difference in sound. Could be a level difference between the sub and mains, crossover behavior, some decoding difference, overall level difference, maybe a speaker wire out of phase, etc...could just be a case of "all else not being equal." In general, if they are calibrated the same, they should sound more similar than not. My guess is bass management...


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## 3dbinCanada

Savjac said:


> So we do admit an amp "Can" color the sound, which would be in the camp that all amps do not sound alike ? Are we to discount the "Almost" half of the respondents that can hear a difference because some others say we can't ? If we are to believe the DBT test then all colas taste alike, fresh and non fresh foods taste the same, corn feed beef tastes the same as grass fed beef, off brand and name brand veggies taste the same. These allegations are just not true. I am sure there are myriad articles on why DBT does not pose a real world offering.


Amps that are operating within their intended design envelope do NOT color sound. Its only when the amps begin to creep into their design limits to the differences begin to materialize. 

Auditory tests don't have to DB. They can be SBT. If a test subject cannot reliably and consistently pick out one amp over the other in a SBT, what makes you think that they can reliably pick out the difference in a sighted listening test? Could it be the other senses are involved that color the expected hearing rather than just relying on the auditory sense?


----------



## Sonnie

Yeah... the Yamaha 3020 I have in my system for review right now sounds a little different from my Denon 4520. Can't figure out whether I like it better or not, but it sounds different because Audyssey and YPAO are two different animals and the response is not the same. Out of the box neither unit sounded right to me. With receivers there are a LOT of variable and probably the only way to compare amps there would be to use the Pure Direct mode and level match the signal. I think it would basically come down to making sure you have enough power to drive your speakers and what features you want versus the price for each unit.


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## 3dbinCanada

Sonnie said:


> Yeah... the Yamaha 3020 I have in my system for review right now sounds a little different from my Denon 4520. Can't figure out whether I like it better or not, but it sounds different because Audyssey and YPAO are two different animals and the response is not the same. Out of the box neither unit sounded right to me. With receivers there are a LOT of variable and probably the only way to compare amps there would be to use the Pure Direct mode and level match the signal. I think it would basically come down to making sure you have enough power to drive your speakers and what features you want versus the price for each unit.


Good point. I run my Yammy without RC and without bass mangement when listening to vinyl or CD preferring my fronts to run full range. When watching a movie on bluray or from my cable box, I engage bot RC and bass management facilities. If you run just your mains full range without bass management or RC, I would be very surprised if you could pick out sonic differences. Engage even bass management and RC and this totally changes the ball game.


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## DeltaDube

wow thought this article was about amps! but your talking about avrs... with 1/4 amps ...

you question about do all amps sound the same is not a good question!

an xpa 1 is an amp!

denon yammy onyko avrs dont compare.. its the power and head room for dynamics that makes the speakers sound better.. avrs dont have power imho..

you need the power to man handle them woofers..

cheers..


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## lcaillo

I think most of the discussion has been qualified by the requirement that the amps be operating at the same level and within their design specs. Whether it is an AVR or a separate amp, there is still an amplifier section. Also, many people are interested in comparisons between similarly rated AVRs or AVRs and similarly rated amps.

So, I disagree with your statement that the question is poorly posed. The question has been clarified by much discussion. I do not think it has been clearly answered by the research, but given the qualification above, it is likely that amps will be more similar than different.


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## Sonnie

Yeah... I don't think I would be powering my subwoofers with an AVR amp, but my AVR powers my Martin Logan Prodigy speakers without any issues whatsoever, as did the Yamaha AVR that I reviewed.


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## 3dbinCanada

DeltaDube said:


> wow thought this article was about amps! but your talking about avrs... with 1/4 amps ...
> 
> you question about do all amps sound the same is not a good question!
> 
> an xpa 1 is an amp!
> 
> denon yammy onyko avrs dont compare.. its the power and head room for dynamics that makes the speakers sound better.. avrs dont have power imho..
> 
> you need the power to man handle them woofers..
> 
> cheers..


Please re read the entire thread "slowly" taking time to think about what's being said. The words "intended design" have a lot of weight around them. In a poor acoustically treated room, an xpa amp will fair worse then AVR with room correction facilities. However, this comparison is not fair to the xpa as its intended design is not have room correction.


----------



## DeltaDube

Sonnie said:


> Yeah... I don't think I would be powering my subwoofers with an AVR amp, but my AVR powers my Martin Logan Prodigy speakers without any issues whatsoever, as did the Yamaha AVR that I reviewed.


 im not a fancy writer.. but in my real world experience.. the sound quality from xpa 1 amps
vs my denon 3313 avr is out of this world how much better the sound quality is .. my xpa 3 amp
is in the middle... 

there is no comparison imho.. 

you need the power to man handle them woofers eh.. ..

Martin Logan is own by paradigm... for my studio 100 v 5 speakers, paradigm strongly recommends 
over amping your speakers to improve the sound quality... and i fully agree... 

i recently had a paradigm manager in my house doing a customer satistfaction survey very happy..
but mostly chatting about sound and equipment etc..

he has the 100s as well and is running them on the athem m1 amps like 2000watts...

makes me think i should have bought the xpr 1s over the older fully differential xpa 1..

there is no way any avr can compare to this type of power and dynamics and sq produced..

i just need to add a fully differential pre amp to get my system set to the black noise level.. 

analog stereo all the way through sonic nirvana!

cheers..


----------



## tonyvdb

DeltaDube said:


> there is no way any avr can compare to this type of power and dynamics and sq produced..


There are lots of receivers that can very easily drive most speakers well past reference levels without distortion. Its the distortion that causes the sound quality to suffer. The Higher end Denon's Yamaha, Onkyo's all have receivers that can drive difficult loads without issues. You can not make blanket statements like that as there are far to many things in the chain that can affect performance.


----------



## 3dbinCanada

DeltaDube said:


> im not a fancy writer.. but in my real world experience.. the sound quality from xpa 1 amps
> vs my denon 3313 avr is out of this world how much better the sound quality is .. my xpa 3 amp
> is in the middle...


Sight bias audio tests usually ends up with a similar conclusion. However, under controlled unsighted listening tests where levels are matched such that the Denon is operating well within its design limits, I very much doubt that you could hear a difference. Yes the XPA1 and 3 are way more powerful then the Denon and this power opens your options in loudspeaker purchases. However, if you compared both sight unseen where the output levels are matched between the two units that is still well within the design limits of the Denon, you would not be able to tell a difference.

I may qualify this.... I couldn't find any reviews on the Studio 100 V5 that showed the impedance swing of your Paradigms. I did see reviews on the V3 of the 100s and the Sudio 60 V5. Based on those reviews, I would extrapolate that the Paradigms are indeed a more difficult speaker to drive despite Paradigms claims of 8ohms and moderately high efficiency (90+db in room) . That being said, an AVR such as your Denon could be easily pushed beyond its intended design limits in a large room depending on how loud one wants to play it. Bottom line, one has to pick the right tool for the job. Dismissing an AVR's capabilities because you are asking more of it then what it was originally designed for is a flaw in your logic.


----------



## gdstupak

DeltaDube said:


> ... paradigm strongly recommends
> over amping your speakers to improve the sound quality... and i fully agree...


Of course you want some head room, but drastically over amping does nothing but waste your money. If your speakers only need 500w to sound their best without distorting, then having 2000w on tap does nothing more.

Also, unless you are pushing your xpa3 too hard, I believe it should be indistinguishable from the xpa1.


----------



## lcaillo

DeltaDube said:


> im not a fancy writer.. but in my real world experience.. the sound quality from xpa 1 amps
> vs my denon 3313 avr is out of this world how much better the sound quality is .. my xpa 3 amp
> is in the middle...
> 
> there is no comparison imho..
> 
> you need the power to man handle them woofers eh.. ..
> 
> Martin Logan is own by paradigm... for my studio 100 v 5 speakers, paradigm strongly recommends
> over amping your speakers to improve the sound quality... and i fully agree...
> 
> i recently had a paradigm manager in my house doing a customer satistfaction survey very happy..
> but mostly chatting about sound and equipment etc..
> 
> he has the 100s as well and is running them on the athem m1 amps like 2000watts...
> 
> makes me think i should have bought the xpr 1s over the older fully differential xpa 1..
> 
> there is no way any avr can compare to this type of power and dynamics and sq produced..
> 
> i just need to add a fully differential pre amp to get my system set to the black noise level..
> 
> analog stereo all the way through sonic nirvana!
> 
> cheers..


You don't have to be a fancy writer to communicate, but please do try to use complete sentences and reasonable grammar. We have many readers from many countries for whom English is hard enough to understand without making it harder.

You said yourself that the question is not a good one. That is why we have discussed it in terms of same level and within the operational design limits of each amp. There are many variables that affect performance, as Tony says, and to make the discussion meaningful one must qualify it properly. As 3dbinCanada suggests, read more of the thread and get the context before criticizing the question. If you want to start a thread to discuss why you feel larger amplifier capacity is important, you are welcome to do so. But that is not the topic of this thread.


----------



## yoda13

DeltaDube said:


> im not a fancy writer.. but in my real world experience.. the sound quality from xpa 1 amps
> vs my denon 3313 avr is out of this world how much better the sound quality is .. my xpa 3 amp
> is in the middle...
> 
> there is no comparison imho..
> 
> you need the power to man handle them woofers eh.. ..
> 
> Martin Logan is own by paradigm... for my studio 100 v 5 speakers, paradigm strongly recommends
> over amping your speakers to improve the sound quality... and i fully agree...
> 
> i recently had a paradigm manager in my house doing a customer satistfaction survey very happy..
> but mostly chatting about sound and equipment etc..
> 
> he has the 100s as well and is running them on the athem m1 amps like 2000watts...
> 
> makes me think i should have bought the xpr 1s over the older fully differential xpa 1..
> 
> there is no way any avr can compare to this type of power and dynamics and sq produced..
> 
> i just need to add a fully differential pre amp to get my system set to the black noise level..
> 
> analog stereo all the way through sonic nirvana!
> 
> cheers..


I think this is just a case where high volume is perceived as "quality". Also, if you want to talk about "watts" and volume, you should probably talk about speaker sensitivity and to a lesser extend, speaker resistance.

I have yet to come across an instance where "over amping" your speakers will somehow add or create extra details that wasn't on the original recording. What will improve quality (and quality is subjective) is the type of recording you're listening to, the type (brand) of speakers your use, your speaker placement, and of course, the room you're in.

And when, as mentioned above in all the excellent comments, when working within it's specs, an amplifier (or amp section of an AVR) will do just that, amplify. When listening to a recording, we listen through our speakers, not our amps.

Having said that, when someone can explain with common sense and prove to me scientifically that an amplifier alters the sound of the original material, I will gladly change my tune.


----------



## TheHammer

yoda13 said:


> I think this is just a case where high volume is perceived as "quality". Also, if you want to talk about "watts" and volume, you should probably talk about speaker sensitivity and to a lesser extend, speaker resistance.
> 
> I have yet to come across an instance where "over amping" your speakers will somehow add or create extra details that wasn't on the original recording. What will improve quality (and quality is subjective) is the type of recording you're listening to, the type (brand) of speakers your use, your speaker placement, and of course, the room you're in.
> 
> And when, as mentioned above in all the excellent comments, when working within it's specs, an amplifier (or amp section of an AVR) will do just that, amplify. When listening to a recording, we listen through our speakers, not our amps.
> 
> Having said that, when someone can explain with common sense and prove to me scientifically that an amplifier alters the sound of the original material, I will gladly change my tune.


For the most part, I agree with what you said. 

I am not certain where speaker resistance comes in. Usually we refer to impedance, since audio is AC. Impedance is important only when a certain amp cannot handle the load. Nominal impedance rating on a speaker is a bit of a joke as the impedance can vary widely by frequency. Looking at a curve of impedance vs. frequency is entertaining if not scary.

http://www.soundstagemagazine.com/measurements/bw_dm303/impedance.gif

Speaker efficiency can affect how loud and amp can play, before it clips / distorts.

"When listening to a recording, we listen through our speakers, not our amps." I would suggest that we listen via the entire audio chain, including mics, recording, amps, etc. But if I were to interpret your remark, I would agree that speakers (plus the room and speaker placement) have the greatest effect on the sound.

"prove to me scientifically that an amplifier alters the sound". I am a firm believer in controlled double blind testing, because that removes our subjectivity from the decision. I believe that testing has indicated that tube amps sound different. It is thought that tubes have much higher levels of even-order harmonics which we describe as 'warm'. It is a distortion, even if most find it to be pleasant.

However, I have never seen a proper (levels set, not clipping) double blind test conducted where quality transistor amps have sounded different. But stating this to a "golden ear" is like waving a red flag in front of a bull.


----------



## yoda13

TheHammer said:


> For the most part, I agree with what you said.
> 
> I am not certain where speaker resistance comes in. Usually we refer to impedance, since audio is AC. Impedance is important only when a certain amp cannot handle the load. Nominal impedance rating on a speaker is a bit of a joke as the impedance can vary widely by frequency. Looking at a curve of impedance vs. frequency is entertaining if not scary.
> 
> http://www.soundstagemagazine.com/measurements/bw_dm303/impedance.gif
> 
> Speaker efficiency can affect how loud and amp can play, before it clips / distorts.
> 
> "When listening to a recording, we listen through our speakers, not our amps." I would suggest that we listen via the entire audio chain, including mics, recording, amps, etc. But if I were to interpret your remark, I would agree that speakers (plus the room and speaker placement) have the greatest effect on the sound.
> 
> "prove to me scientifically that an amplifier alters the sound". I am a firm believer in controlled double blind testing, because that removes our subjectivity from the decision. I believe that testing has indicated that tube amps sound different. It is thought that tubes have much higher levels of even-order harmonics which we describe as 'warm'. It is a distortion, even if most find it to be pleasant.
> 
> However, I have never seen a proper (levels set, not clipping) double blind test conducted where quality transistor amps have sounded different. But stating this to a "golden ear" is like waving a red flag in front of a bull.


I agree with the your tube amp comment as you are not the first one to mention it like this and I do not have sufficient experience with them to sustain any comments I would make. As for distortion, mmh, if one likes it, great but I don't think it qualifies as "quality" as it wasn't intended by the audio mixer. But then again, apparently Tron Legacy was mixed with clipping in the low end. 

As for impedance (yes, I used the wrong terminology), just covering my ends.

I suppose I have a rather simplistic approach I guess :huh:. But you got what I was trying to say 

I'm just annoyed at the poster I was quoting spreading all over the forum is claims about amps and watts and more amps and over amping equals quality.


----------



## DeltaDube

tonyvdb said:


> There are lots of receivers that can very easily drive most speakers well past reference levels without distortion. Its the distortion that causes the sound quality to suffer. The Higher end Denon's Yamaha, Onkyo's all have receivers that can drive difficult loads without issues. You can not make blanket statements like that as there are far to many things in the chain that can affect performance.


well i agree to disagree...  not even close in the sonic performance..

cheers


----------



## DeltaDube

seems like this is an anti power site...

hey run your avrs you will never know what your missing.. sonic nirvana!

if you line up some powerful mono blocks amps and try em out you will understand..

cheers..


----------



## tonyvdb

DeltaDube said:


> seems like this is an anti power site...


No, this is a site that deals with facts. 1000watts of power on speakers that handle 400watts is a waste of money and can damage them if over driven. 
200watts is more than enough power to drive any good quality speaker to well past reference levels without even breaking a sweat.


----------



## lcaillo

I don't really agree, necessarily Tony. But this is a different topic deserving of another thread.

Please, lets avoid sarcasm, comments like "silliness" and judgments about the site. We are not anti- anything except rules violations. We welcome all perspectives and we will be happy to entertain discussion of the value of extra power or any other A/V topic. We do have very strict rules about being respectful and keeping threads on topic, however. So please read them. They protect everyone's ability to express their ideas in a safe, clean environment.


----------



## TheHammer

yoda13 said:


> I agree with the your tube amp comment as you are not the first one to mention it like this and I do not have sufficient experience with them to sustain any comments I would make. As for distortion, mmh, if one likes it, great but I don't think it qualifies as "quality" as it wasn't intended by the audio mixer. But then again, apparently Tron Legacy was mixed with clipping in the low end.


I think we are on the same page, or ah, frequency here. 

My comment about distortion might not have been clear. The reason that (some? many?) people like the tube amp sound is because tubes create even order harmonic distortion. This sounds warm / pleasant to people and they characterize transistor amps as sounding 'harsh' because they do not sound 'warm'.

My argument is that tube amps, generally, add something that is not there. It is distortion, even if it sounds pleasant. Distortion is an odd term to use here since we normally associate distortion as being unpleasant. My point is just because tubes may sound warmer, they are adding something to the music (even order harmonics) and changing the music in any way is not something an amp should do. Therefore, transistor amps are (generally) superior to tube amps because they change the music less than tube amps do.


----------



## lcaillo

TheHammer said:


> I think we are on the same page, or ah, frequency here.


Ahhh, but are we in phase? I think we are, as I agree on the tube sound.


----------



## AudiocRaver

lcaillo said:


> Ahhh, but are we in phase?


Does it matter? It is said that we can't hear phase.:R >>>>> Bad joke.


----------



## Sonnie

DeltaDube said:


> the sound quality from xpa 1 amps vs my denon 3313 avr is out of this world how much better the sound quality is .. there is no comparison imho..


I owned a pair of XPA-1 amps that powered my MartinLogan Prodigy speakers. My Denon 4520 AVR and the Yamaha 3020 AVR, were both able to power my Prodigy speakers equally as well as the XPA-1's. There have been zero deficiencies and I would challenge anyone to come to my house with a pair of XPA-1's and let's do a listening test to verify those claims of hearing a difference. 



DeltaDube said:


> Martin Logan is own by paradigm...


Actually I believe ShoreView Industries owns both companies... but it really matters not, they are speakers that have significantly different designs... and I highly suspect that the Studio 100's are easier to drive than the Prodigy speakers. 



DeltaDube said:


> there is no way any avr can compare to this type of power and dynamics and sq produced..


Yes... there is definitely a way... bring your amps to my house and we can hear no difference together. :bigsmile:



DeltaDube said:


> seems like this is an anti power site...


Not at all... we love power... got to have it to run things. Oh wait... you mean power amps. Still not at all, we love power amps. Emotiva is a sponsor and I have owned several of their power amps. I would probably still own the XPA-1 amps if I had plenty of room and want to use more power (electricity) in my home to run them. I just don't really have room and I seriously do not need them to improve on my sound, because they don't improve anything. That does not mean I don't like them or would not ever own them... I did. Have no issues with anyone wanting to buy them... encourage everyone to give them a try. If they work for you, great!



DeltaDube said:


> hey run your avrs you will never know what your missing.. sonic nirvana!


Right... we will never miss anything... so we certainly won't know what we are missing. :whistling:



DeltaDube said:


> if you line up some powerful mono blocks amps and try em out you will understand..


Bring them on... let's line them up. Whenever you are ready. :T


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## Savjac

Well it has been pretty quiet in this thread of late, probably good to keep it that way. 
Glad everyone is doing well.


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## Gregr

I like Sonnies response, I would add



I have been following along and I am sure all that I say has been alluded to many times over but not specifically described with any detail. This is an interesting topic one I have been researching for most of my adult life. I am interested in this topic, I call perception or at least a median proportion of what we hear here is simple perception. But the details change with each individual and individual piece of equipment and time of day, type of music or dialog or sound effect and don't forget mood and expectation..., we could go on describing variables in infinite details as well. I do not see any one answer as being a one line explanation not even a one page description in fact the book has not been written that fulfills each of our varying beliefs of electronic engineering, materials selection and environmental variety. I believe we have not agreed on a solution to the question because there are too many partial solutions, singular beliefs, defences, accusations and to refer to the least of reasoning, that is, this is an observation or a bit of science with simple observation that is a fact and describes a difference or similarity but only to a point. 


This is not to say there are badly engineered and assembled electronics for sale everywhere even some with high praise. Also even a power amplifier with issues can sound acceptable with specific improvements like dedicated clean power, high purity copper in all areas including torroids, cables and interconnects. In addition, the best recordings will offer the most lifelike details. A well mastered analog and/or digital recording is a very high priority along with a play back system using equipment equal to the equipment used in recordings and mastering. If you do not at least agree with this please do not reply to my post. 


Earlier, I watched a TED talk, where Michael Shermer' offers great examples of “Why People Believe Wierd Things”. Michael Shermer (MS) is a “debunker” who although he deals with exposing phenomena such as ghost and alien claims many of which are hoaxes from people like yours and my neighbors who maybe got a little too loud at a party etc etc.; but he did present several interesting observations. Take a look -


http://www.ted.com/talks/michael_shermer_on_believing_strange_things.html


Please, watch this until at least gets to the Led Zepplin analysis..., you'll love it


Of course I don't agree with all of what MS presents as debunking and factual but in one example MS stands with a framed grilled cheese sandwich with a likeness of the virgin Mary toasted onto it. Here there are two interesting facts. One, a Las Vegas casino owner paid $28,000 on eBay for the Virgin because he believes in something or two he had not seen the Jane Russel image. Our expectations rule!!! Actually, it is the *“EGO”* I don't know how much clearer it could be. Sometimes we do not hear because it does not serve the ego!!!


I hope you hear the example passage from Led Zeppelins' “Stairway to Heaven” what we hear and next what we are told to “listen for” I believe is exactly the lesson we need to learn in all of this discussion of, “is there a difference...???”. Expectation (it is all about ego) But again, sound playback details can be improved upon..., at least more details and quieter sound floor. 


If I had two identical amps, recordings and speakers, interconnects and AC..., I could show improvements but then we are mostly left with opinion still, even in the face of measurable facts. Like the Stereophile article where two electronics and sound engineers find measurable differences. One person expresses disbelief in the facts and the discussion continues.


Bottom Line. I love the sound of my Denon AVR with the balance of cables and interconnects and speaker choices..., it is all perfectly balanced. I've owned others and listened to so many more this is my best effort yet.


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## flamingeye

I don’t know about between class A/B amps and class A/B amps, but I definitely heard a difference when I compared a Harman/Karden A/B class amps to the Emotiva IPS-1 class H amp I think what made the biggest difference though was the noise floor it was a lot lower in the Emotiva amp it sounded more clear and refined . I think it helps if you do the testing on your own system because you no your system intimately going to someone else place on a system your unfamiliar with I would think could skew the test . As for A/B amp to A/B amp of comparable power I wouldn't think there would be much difference if any but I haven’t compared any so can’t comment on that .


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## fmw

As long as the amps keep frequency response within a couple of db of flat and have distortion below 1%, any differences in amplifier performance are not audible. They simply aren't. If you hear differences then that is most likely due to differences in volume (people will prefer the louder presentation every time) or expectation. By that I mean that, if you expect something to sound better, your brain will give you what you want. It fools us all the time. If you really want to understand audibility you need to get involved in some bias controlled listening tests. That way we give the brain nothing to work on other than the sound itself.

Sonnie, above is quite correct. If you take him up on his challenge, I'd like to put some money on him. I can always use some spare cash.

There are two situations in which an outboard amp is necessary and they are both actually pretty rare. The first is requiring more power than a receiver can provide because of insensitive speakers or a very large listening area. The truth is most of us use only a fraction of the power a receiver has available. 

The other is dealing with low impedances at high volume for significant periods of time. Very few home theater speakers actually cause much stress on amplifiers because of impedance. The low points in impedance curves are usually at a frequency we don't encounter much or that we don't encounter for very long. It wouldn't even make sense for speaker manufacturers to make speakers that would burn up amplifiers. Ask around. See if you can find anybody that has cooked an amplifier with a "low impedance" speaker. You aren't likely to find many.

There are situations which do require outboard amps but, as I said, they are fairly rare. Most outboard amps are bought because people believe they will help, not because they actually do help.


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## fmw

Gregr said:


> Like the Stereophile article where two electronics and sound engineers find measurable differences. One person expresses disbelief in the facts and the discussion continues.


All differences in measurements aren't audible. That's pretty straightforward. While .1% THD and .01% THD are a factor of 10 apart from each other, neither is audible.


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## flamingeye

I’m quit the layman when it comes to this type of thing but if the outboard amp was more powerful wouldn't it have better headroom for that instantaneous peaks that a lot of music will produce and wouldn't that be audible ? I’m not trying to say your wrong here just trying to learn more , also like I noted previously wouldn’t a lower noise floor make a difference and be audible too I mean as for making the music sound clearer crisper in the lower light passages when the music softens.


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## chashint

Assuming the less powerful amp has enough headroom to play at the desired volume without clipping, additional headroom does not help anything other than ego.


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## lcaillo

Suppose you have two amps with essentially the same design and the same power rating at 8 ohms. You have a speaker that has a nominal impedance of 8 ohms but drops to 2 ohms at some frequencies. You never drive the amp to voltage clipping. One amp has a much larger transformer and much more capacity in the power supply, and the other can produce the same voltage output, but has a minimal power supply. Played at the same volume, when the impedance drops, the voltage swing at those frequencies is less so the amp is not in voltage clipping, but the second amp cannot deliver the current that the first can.

Do the amps sound the same? Assume that they are rated at the same distortion at 8 ohms and the same bandwidth.

Suppose further that the speakers present a highly reactive load and though similar design and similar specifications, one has a significantly higher output impedance than the other? Do they sound the same?

Now combine the two cases above. Do the amps sound the same?

I agree that in general, amps working within their power rating with similar designs will sound essentially the same. There are, however, aspects of design that do not get reflected in commonly available specifications. I would only go so far with the assumption of similar sound with similar power and distortion ratings. There is almost always more to the story. The problem is that many in this industry take some variable that MIGHT make a difference under certain conditions and generalize it into a "feature" that makes one product superior to another when under typical conditions or in the range of application of audio has not been shown to have any practical impact on performance.

My point is that both sides of this and most other similar arguments make assumptions that might not always be valid. There is often more to the story than we assume. There are many products on the market that are designed well, many that are not, and many that get applied incorrectly.


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## fmw

I think the fairest way to describe it is that, if an amplifier has a frequency response in the audible range within a couple of db of flat and has THD of less than 1% it will sound just like every other similar amp as long as it isn't operating under stress.

The tube amps that are audibly different from the norm all have THD over 1% - some as high as 5% so those are covered in the first paragraph. We've tested a few high end tube amps with very low distortion that are indistinguishable from solid state units. Those units are very well designed and very expensive.

If an amp is unable to handle a very low impedance elegantly then I describe it as being under stress. Stressed amps can display some audible characteristics. If it is driven to clipping then the audibility of that distortion is as obvious as ones nose.

My advice is to use speakers and room acoustics to create the sound quality you are after. The stuff in front of the speakers is usually not the answer to better sound quality.


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## lcaillo

I do not agree that flat frequency response, harmonic distortion, and lack of clipping are necessarily sufficient conditions for amps to sound the same. There are other conditions not accounted for by these. I do agree that most of the time these are sufficient, but I simple reject the assumption that we adequately account for variations in audible performance with only these measures.

I agree with your last statement, mostly.


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## chashint

http://tom-morrow-land.com/tests/ampchall/rcrules.htm 
http://tom-morrow-land.com/tests/ampchall/index.htm


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## Mike0206

chashint said:


> http://tom-morrow-land.com/tests/ampchall/rcrules.htm
> http://tom-morrow-land.com/tests/ampchall/index.htm


Interesting challenge.


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## fmw

lcaillo said:


> I do not agree that flat frequency response, harmonic distortion, and lack of clipping are necessarily sufficient conditions for amps to sound the same. There are other conditions not accounted for by these. I do agree that most of the time these are sufficient, but I simple reject the assumption that we adequately account for variations in audible performance with only these measures.
> 
> I agree with your last statement, mostly.


Can you tell me about experiences in which something other than frequency response and distortion made an audible difference? After years of bias controlled testing, we weren't able to come up with anything else. As an example we were never able to detect a sonic difference between any hi fi solid state amp and another. And we tested things like a 250 watt per channel Krell against a Sony receiver. No audible difference at all with B&W 802 matrix speakers.


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## KelvinS1965

I don't know if it's something that has been measured, but one thing I can think of is how the feedback circuit(s) in an amplifier stage might effect the phase at different frequencies. You could also have different amounts of distortion at different frequencies, though whether this has an audible effect I don't know, but I'm just pointing out some areas of possible technical differences between otherwise similarly specified amplifiers. There are lots of other things we could measure (or come up with ways to measure) other than the standard S/N, % THD and frequency response which might help explain why some feel that amplifiers sound different,so I feel that just using those measurements isn't necessarily capturing all that the amplifier does to the signal.

I have to confess two things:

1. I used to build, service and repair amplifiers for a living, though they were for Armed Forces rather than 'hifi' amplifiers, so the testing we did as part of QC was purely the basic frequency response and output/distortion check at 1Khz.

2. I run separate power amplifiers in my set up since I have an AV processor, so they are necessary. I did add a second power amp so I could bi amp my front three speakers and I felt it was worthwhile, though of course it could be placebo...I do tend to listen at pretty high levels (-5dB below reference usually) though my speakers aren't particularly hard to drive/inefficient.


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## fmw

We really can't hear phase alignments unless the phase is different on each side of the system or in each ear. It would be pretty abnormal to encounter an amp with misaligned phase on each channel. But, if you did, I think it would be audible as would any number of other defects in an amplifier. Distortion does indeed vary with frequency but as long as it is under 1% we can't hear it so it isn't important. My point is that modern HiFi amps basically sound the same as long as they are working correctly and within their design parameters.


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## KelvinS1965

Then we shall agree to disagree. :T I'm very reluctant to return to using a receiver rather than pre pro set up, but I do like to listen at higher levels. Personally I don't believe that one box with all the channels drawing from the same power supply is the best way to reproduce sound. In my own experience trying this way gave a harsh sound at the higher levels I like to listen at, but separate amps didn't.

However, lets just leave it there since I don't want to get into a pointless argument when we both see things differently and won't convince either of the other's view.


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## fmw

Sorry, I assumed from the title of the thread that the participants wanted to discuss amplifier audibility. I misunderstood. Take care.


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## KelvinS1965

I did, but I just can't see us agreeing on anything, so it's pretty pointless to continue and I haven't the time or inclination to argue further. Just remember that a lot of audio measurements are done using a simple sine wave and not the complex waveforms of music, so IMHO some of the standard measurement techniques don't capture and/or explain everything.

Take care.


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## english210

I had a Yamaha amp running off a Yamaha receiver, and noticing at higher volumes, the sound quality suffered greatly. After reading threads like this, posting questions, and more research, one of the amps I had been pointed towards came up for sale used, so I figured I'd try it. Nothing else changed, it was just pull out one 2 channel amp, plug in another, both rated at 150wpc. Not a scientific A-B, nothing like that, just 'lets see if this helps'. It did, massively. The speakers are 25 years old, and I've never heard the bass sound as tight and controlled as it did now, and the harsh stridency in the highs was reduced a lot. Even my wife heard a difference, and she's not a 'listener'. It wasn't about volume, it was purely the control and musicality bumped a notch. 

No doubt there are the 'you wanted to hear a difference, so you did' naysayers, and that's fine. I'm sure there are technical reasons that could explain the difference, like current capacity, and the 'new' amp is twice the weight of the old one, but the plain truth is that the sound quality improved. I did hope for a difference, but I expected to have to try to listen for it. The purpose was to 'tame' harsh highs at higher volume, but the result was immediately noticeable in the bass - I don't use my sub for 2 channel any more. YMMV, IMHO, etc, etc


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## Sonnie

The older Yamaha may very well not have been rated as accurately as the newer amp... may not have been designed to drive your particular speakers... could have been faulty, may have had a different frequency response, etc., etc. There are a number of variables that could be causing the difference. Obviously there was some type of design difference (or issue) if you noticed a dramatic change. It would not necessarily surprise me that some newer amps sounded better than some older amps... all depending on who made them and when they were made. I don't think that has ever really been questioned.


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## english210

The amp I had been using was one I'd used since I got the speakers. The system was essentially unchanged all that time, since the late 80's. I got a deal on the receiver, and hooked it up to the speakers alone at first, then re-added the amp to the system, and didn't hear much difference. This was before I added any surround speakers, so the amp and receiver were both only driving the mains. Both rated at 150wpc. That was partly why I wasn't expecting much improvement with the 'new/used' amp, but there was. I don't believe the original amp was 'defective' in any way, or not working properly, but obviously I can't be sure it still measured up to it's original specs. It did at least equal the new receiver, though.

As I said, this wasn't a specific test, designed to find out if I could hear a difference. I was looking for a solution to the problem, and tried the amp, and got a bigger benefit than I expected. The area I was 'looking' for improvement was the highs, which I got, but the dramatic difference was in the bass. So for me, the question of 'can you hear a difference between amplifiers' is a resounding yes, however I would also say that if you have 2 new amps of similar specs and price points, I wouldn't want to bet on hearing a difference....I guess it's a question of thresholds - and perhaps each person has a different threshold of audibility, just as we have different thresholds of pain...??


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## Sonnie

Yeah... it was not just a general question, it was qualified. If you are hearing dramatic differences, then something was likely array if you had two good quality amps with basically the same specs. 

From all that I can gather, even the golden ear guys will admit that the differences they claim they hear between two different amps are very subtle... not dramatic. Of course several well conducted double blind listening tests suggest that those differences cannot be identified, even by some golden ear guys. Yet, there are those that have never participated in DBT that suggest there are differences, but not dramatic.

I can't say one way or another with 100% certainty between two quality amps, other than I can say that I have never been able to pin point any particular differences, unless the amp was simply unable to power inefficient speakers (I have certainly heard that difference and it was indeed dramatic and extremely noticeable distortion). I think the only way I could ever prove it for certain to myself would be in a DBT. Then there are those that suggest some differences we hear can't be tested, but again, they are very subtle differences, not dramatic. I think in all cases, dramatic differences can be tested and identified.


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## Peter Loeser

Sonnie said:


> I think the only way I could ever prove it for certain to myself would be in a DBT. Then there are those that suggest some differences we hear can't be tested, but again, they are very subtle differences, not dramatic. I think in all cases, dramatic differences can be tested and identified.


Not sure if this has been suggested already but what about a Home Theater Shack DBT of some popular amps? Along the lines of the recently completed speaker shootout. I've always been curious about this myself. I am somewhat convinced I have heard differences between similarly spec'd amps, but have never done a DBT, which I agree would be the only way to really tell.


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## Sonnie

I would certainly be up for it.


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## chashint

I would like to see this too.
Only difference I would throw in is do it with amps having significant variation in specs and to pick a set of speakers that are allegedly hard to drive and let er rip.

I am of the predisposed opinion there will be no audible differences at "normal" listening levels.
But if proven wrong it would give me a reason to buy a new toy.


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## Peter Loeser

I am all about buying new toys but I would honestly feel better about proving to myself that my ears could not detect a difference between amps with similar specs over a range of prices.


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## fmw

I highly recommend it, guys. Nothing like a well done bias controlled test to understand hearing bias. It is fussy, time consuming and boring but worth the trouble. Let me know if you need any suggestions.


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## Sonnie

Suggestions are definitely welcome... here we go: *Double Blind Listening Test*


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## tgetahoun

Offcourse we van hear the difference, if that was not the case, we would not have seen price difference.

If you want to know for your self upgrade your amp, to a better built and exppensive Amp and you shall notice the difference


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## vidiot33

Hello fellow home theater enthusiasts: I find this topic fascinating! I think all the major points of the discussion have been pretty well covered and civilly ! I would add a couple of points:
1) in my opinion, all of us possess differing frequency sensitivity. Although I'm skeptical of the claims of some, I would at least allow for the possibility that some can hear things in amps, preamps even to a lesser degree, wiring that I may not hear.
2) home theater generally creates far greater demands on amps and speakers than most music, especially in heavy action scenes. This is where headroom may result in noticeably improved sound.
3) Julian Hirsch, late of Stereo Review studied this phenomenon and concluded that the synergy of different components (or lack thereof) can in fact make an audible difference in sound quality.
4) an article I read (sorry don't remember the author) claimed that clipping occurs more frequently in amps than is commonly believed. If this is the case, this would seem to me to be an argument in favor of high current amps, especially for home theater at loud levels with insensitive speakers ( I have Magnean 3.7's)


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## Bigun

High current - depends on the speakers. With speakers that are low impedance (e.g. 2Ohm to 4Ohm) or any speaker that has low impedance dips at certain frequencies then the amp may be taxed to provide extra current. For well behaved speakers the amp may run out of voltage headroom before it runs out of current. The issue regarding sound though, may be that the amp has some kind of 'protection' that limits clipping, so called 'soft clipping' for example, all of which can affect the sound depending on how they are implemented.

From what I can see, most HT receivers have plenty of voltage drive but often have undersized power supply capacitance (and undersized transformers and hook up power rail wires) given the large demands and the number of power amplifier channels all feeding off the same supply rails. Therefore, when asked to provide current the supply rail voltage collapses. A decent amount of power supply capacitance takes up a lot of space in the box so even before the bean-counters get worried about the cost of the parts there may already be inadequate space for a good set of capacitors. I am thinking of modifying my receiver by adding an out-board power supply for the power amplifier. The amplifiers in most units may therefore be limited by their power supplies more than any design limitation within the amplifier itself.


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## AudiocRaver

Your idea makes quite a bit of sense. I have wondered why more amps and AVRs are not built that way (power supply in a different box) in the first place, other than "it looks funny."


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## Sonnie

I don't think anyone really argues the differences in sound caused by clipping. It is when we get into things like this amp has more bass, the bass is tighter on this amp, the sound is more open on this amp, the mids are more pleasant, more laid back, more forward, this amp is too bright, etc, etc, and a lot of other fancy terms that some of the elite names in the review business use. Those are the ones I would question and would like to hear in a blind testing situation.


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## Savjac

I believe that the buying market is speaking when it comes to the products being presented. Separate components may be less than desirable for the general public. 

Is there actually a way to pack a better power supply circuit into these boxes that are already crammed with 9 channels, computerized sound control, and what have you. It also seems that there is a price point that is hard to pass AND provide a good reliable product. Some processors are even stopping the addition of rca inputs and outputs in favor of HDMI so there is a pattern here.

Nothing seems to be getting simpler, but rather, more and more complex without any actual improvements sonically without engaging DSP.

Could be ??

I also believe that electronics do need more current flow so as to be able to control the speakers, they cannot do it themselves. Its is akin to the difference between horsepower and torque. They work hand in hand, horsepower is nice for moving something quickly and easily, but try pulling a trailer up a hill without a substantial amount of torque and it just won't work well.


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## Savjac

Please allow me to just throw something out there without causing too much of a stir and please do not think I am trying to disrespect anyone's thoughts or ideas; that is not my intent here.

I would put forth that the Blind Test procedures have been done in most every way imaginable and yet it would appear that the same results are arrived at by those who participate. Some of the boundaries have changed in that now the components can be picked by the participants, additional time is allowed and favorites in music can be used in the tests. These are given parameters, and once again, the end result is predictable on almost all occasions. So in science, does this prove there are no differences between test amplifiers OR is this test designed to reach a certain result and as such faulty ?

Since the vast majority of these blind tests result in the same end, there is really no reason to do this test any longer, it is the dead horse argument. Maybe its time to try something new ??

Over our long history, there have been many many theories that were thought to be tried and true until another theory came along to make changes in the original thought process. We can look to Edison who could have quit looking for a proper filament for his light blub because early on he could not get any combinations to last more than a short while. How easy would it have been for him to say it just does not work ?

Early in this century, doctors blamed the death of women shortly after childbirth on the women being "Unclean" in a morality way rather than looking further and finding that by operating on several people in a day without the doctors cleansing their hands and rendering untold infections from one patient to another.

I cant even imagine the issues Galileo went through when he presented his thoughts on Heliocentrism. 

None the less, maybe something new is in order here and maybe it is something as simple as Listening to the product on demonstration as it was designed to do. It would appear to me that no "thing" in the chain of music reproduction was designed to be listened to in short bursts or under unfamiliar surroundings or under the duress of the belief that no differences exist. Some time ago, a friend of mine did an interview with Earl Geddes regarding his thoughts and beliefs on these subjects and Earl had much to say including this:
_
"The first issue that I found for which psychoacoustics could be a help had to do with what I saw as incredibly unstable subjective evaluations. In my job I had witnessed known authorities completely contradict their own opinions when they did not remember what they had originally said. I saw how easily people could be swayed in their opinions by external forces and found that I could convince people of things that I knew were false by simply telling them what they were hearing (which was not the case)."_

To be fair, further reading finds Earl presenting this thought:

_"After several more studies along these same lines, I came to conclude that the more someone claimed to be a “golden ear” the less likely it was that they actually were. Today, I simply do not accept any subjective opinions about sound quality (including my own) unless they were obtained under very rigorous testing protocols – which is an extremely small volume of data." _

So it would appear even the experts are saying in essence we need to, on our own or with friends, try to set some protocol that may provide an answer to these ideas that either all amps sound the same or they do not. With that as the question and knowing that blind tests are not the answer, what is the answer ?
As put forth above it would appear to be listening, spending time with the component in a comfortable environment without any undue influence from outside telling you there is or is not a difference. It seems obvious to me that with so many designs, designers, goals, components, price ranges and untold other factors, there has to be a difference. Mr. Sanders believes in the differences so strongly he makes his own components for his speakers. Carver believes in the differences and has proved it time and again. We could go one, but is it possible to now come up with a new approach for home to set maybe a longer time limit, listening to longer pieces of music on ones own system ?? 

Why or why not ? Please no answers like it has been proved because it really needs to be looked into and no need to cover the same old ground. I tend to agree that with most amps that I could afford, differences will not be huge, assuming same class of amplifier i.e. AB or A etc. When moving into the esoteric amplification I guarantee the differences are there I think.... :innocent:


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## Sonnie

Actually Sanders does NOT believe there are differences in the sound of amps. What he believes is that certain speakers (namely his) need more current to make sure they do not clip the amp.

We need to be sure to not confuse distortion and clipping as differences in the sound of amps. I don't think anyone argues that point. What I think most argue is that when there is no distortion and no clipping, most amps will sound the same. That may not necessarily be a "guarantee", but it is what has been proven thus far.

The part that bothers me the most is people claiming they hear seriously drastic differences. I might be more likely to agree that there are subtle differences that some people can hear between two amps... and not that they are necessarily better or worse differences, just differences.


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## vidiot33

Sonnie said:


> Actually Sanders does NOT believe there are differences in the sound of amps. What he believes is that certain speakers (namely his) need more current to make sure they do not clip the amp.
> 
> We need to be sure to not confuse distortion and clipping as differences in the sound of amps. I don't think anyone argues that point. What I think most argue is that when there is no distortion and no clipping, most amps will sound the same. That may not necessarily be a "guarantee", but it is what has been proven thus far.
> 
> The part that bothers me the most is people claiming they hear seriously drastic differences. I might be more likely to agree that there are subtle differences that some people can hear between two amps... and not that they are necessarily better or worse differences, just differences.


I think these are excellent points. I would simply add that if clipping is a relatively common experience (and at least one well-regarded acoustical engineer believes it is), then it makes sense to purchase an amp that gives sufficient headroom for your needs. In larger rooms, at loud listening levels and with inefficient speakers, many receivers will be driven to clipping, and will not sound good, and these environments would be better served with dedicated power amps.


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## Savjac

Sonnie said:


> Actually Sanders does NOT believe there are differences in the sound of amps. What he believes is that certain speakers (namely his) need more current to make sure they do not clip the amp.
> 
> We need to be sure to not confuse distortion and clipping as differences in the sound of amps. I don't think anyone argues that point. What I think most argue is that when there is no distortion and no clipping, most amps will sound the same. That may not necessarily be a "guarantee", but it is what has been proven thus far.
> 
> The part that bothers me the most is people claiming they hear seriously drastic differences. I might be more likely to agree that there are subtle differences that some people can hear between two amps... and not that they are necessarily better or worse differences, just differences.


Good points all but in reading Sanders discussions on this matter, he presents his thoughts thusly:
_
"As an aside, I continue to be amazed by the fact that most audiophiles are not aware that they are using underpowered amplifiers that are clipping and distorting most of the time. It is easy to show that most speakers need around 400-500 W/channel to play dynamic music at the loud levels audiophiles enjoy."_

There is a large discussion of poor power supply implementation of which we have been discussing on the forum. Accordingly we may take from this expert that most amps will be clipping on peaks and as such this would put most amps in the same category. How do we present that amp "A" and amp "B" are or are not equal and will or will not sound the same based upon his theorem. The thought that keeps being recirculated is that if we pick is that IF no clipping is encountered all amps sound the same. How can one predict that no clipping will occur and how can one then predict which amps to include in a comparison and which amps to exclude ?

Lastly, is there a reference to hearing "Drastic" differences between components ? Not sure that drastic was ever mentioned, differences yes, drastic no.

Lastly, we both chose to increase the power to our Electrostatic speakers by adding basic amplifiers to our AVR's. We both tried without the basic amps but something was amiss. I cannot put my finger on it, it just did not sound right, did not sound good, did not sound like the music could soar without hitting the proverbial wall. Could we have heard limitations on receiver power supplies ? Just a thought


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## vidiot33

Savjac said:


> Good points all but in reading Sanders discussions on this matter, he presents his thoughts thusly:
> _
> "As an aside, I continue to be amazed by the fact that most audiophiles are not aware that they are using underpowered amplifiers that are clipping and distorting most of the time. It is easy to show that most speakers need around 400-500 W/channel to play dynamic music at the loud levels audiophiles enjoy."_
> 
> There is a large discussion of poor power supply implementation of which we have been discussing on the forum. Accordingly we may take from this expert that most amps will be clipping on peaks and as such this would put most amps in the same category. How do we present that amp "A" and amp "B" are or are not equal and will or will not sound the same based upon his theorem. The thought that keeps being recirculated is that if we pick is that IF no clipping is encountered all amps sound the same. How can one predict that no clipping will occur and how can one then predict which amps to include in a comparison and which amps to exclude ?
> 
> Lastly, is there a reference to hearing "Drastic" differences between components ? Not sure that drastic was ever mentioned, differences yes, drastic no.


Granted, this is a complex issue. We could safely assume that no clipping is occurring if we are driving high efficiency speakers at low levels, or less efficient speakers with high current amps. However, I believe this information should be routinely included in professional amp reviews and is not, while all sorts of other relatively meaningless data is included. I think we can safely say solid states amps not driven to clipping should sound very similar (tubes are another matter), provided, as Mr. Hirsch asserted, that there is no asymmetry between the amp, preamp and speakers. There are a number of variables at play: the efficiency of the speaker, the amount of current the amp can deliver, the material being played, the volume level, the distance from the speaker and any potential comparability issues between components. The take home for me would be: get the most powerful amp within your budget that minimizes the clipping risk. For me personally, that's Emotiva monoblocks...


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## Sonnie

At reasonable levels my Denon 4520 sounded every bit as good at my Emotiva on my MartinLogan Prodigy speakers.

I know that Roger Sanders exaggerates the amount of power needed because he wants to sell his amps, but he was very quick to admit several lower powered amps that would work with his own speakers without clipping. One was the Anthem 225, which is rated at 225 wpc.

He also mainly holds to that power requirement with electrostatic speakers. He will tell you quickly that the more efficient speakers do not require 400 wpc to play at loud dynamic levels. I spent hours on end talking to this man... had two of his amps and his 10c speakers in my home.

Would you call "night and day" a drastic difference? Search for that term and you will find plenty of references by various individuals. I participated in a thread right here at HTS just a few weeks ago where the member claimed what amounted to "drastic" differences between I believe a Sunfire amp and a Behringer EP2500... yet I hear zero difference between my EP2500 and XPR-5. Drastic, huge, significant... and many more terms that I have seen scattered all over the net. I might agree with "subtle", if I ever heard it, but otherwise, nope, don't believe I will ever hear anything more than subtle unless something is wrong with the amp.

Either way... the entire basis of the differences have always been prefaced by the requirement that neither amp is clipping or distorting. And I am of the proponent to get more power than you think you need to be on the safe side.


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## ajinfla

Savjac said:


> Since the vast majority of these blind tests result in the same end...


Hi Jack,

I'm not sure what blind testing you are intimately familiar with, but quite the opposite is true. (Audio) blind testing makes your cel phone work. It allows speech and conferencing over the internet (VOIP). It's why hearing aids work. Human loudness contours, amplitude sensitivity, etc, etc....all determined, quite specifically, by folks being able to hear differences in sounds. That is what blind testing is. A method for science to determine real differences...if they exist. I think you may have conflated a very, very narrow scope of testing - SS vs SS amps operating linearly, with "blind testing".
Folks have no problems hearing differences between (some) tube amps and SS, no problems hearing frequency intensity variations in signals, loudspeakers, distortion levels, etc, etc.
(Audio) blind tests are great at detecting real differences in soundfields, but very poor at detecting imaginary ones (for that we need appropriate methods, like fMRIs, etc.).
Please be clear on what blind testing is, contextually.

cheers


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## Savjac

Er..I have heard subtle differences between "_some_" amplifiers when listened to in my own room using several different types/sets of speakers. Absolutely the word subtle must be used in my experiences and the differences do not show up on every amp or test. For much of my testing I used DQ10's, Maggies and B&W speakers. Maybe not the most normal but it is what we used.

Yes, Night and Day would be considered a drastic difference and I would almost certainly disagree with that statement howsoever it may be used, unless as you say one of the amps on test are not working. Most differences in this hobby, with the exception of speakers should be considered as subtle or on the opposite end of night and day. Well except for my little garage amp which really is bad :gulp:


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## antoninus9

I can usually differentiate between tube vs. solid state by the hum and envelope delay created by the tubes. If asked to differentiate between different tube amps I couldn't do it. The same with solid state. 

If one amp was low power and the other high, I could detect clipping when the system was driven hard.

You can sometimes differentiate solid state amps by their loading. In some units this creates a kind of dullness to the tonal quality, but any A/B test would have to use amps known for these characteristics. 

Generally speaking one amp is as good as the next in my opinion, except when the speakers call for higher current and/or dampening. These situations create audible distortion which can be measured, and is only apparent when the amps are driven to their limits.

Even debating speaker systems is problematic. I can take a pair of JBL 4412As and move them to different rooms in my house and they sound different in each. What does this reveal? 

Some rooms and the layout of furniture, draperies, etc. work well with electrostats, while others work better with more conventional designs.


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## informel

Show me 2 pictures of women and ask me the one I prefer and I will choose the same one 10 times out of 10, you can ask me to look at them for a month and the result would be the same or ask me to touch 2 different fabrics and ask me which one is softer and the result would be the same.


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## Bigun

Music can have a very wide dynamic range and so if you want to, it's relatively easy to make the argument for a powerful amplifier to avoid any clipping. But so what if the amplifier does clip, so long as it isn't very often. It's a tradeoff, you accept the benefits of lower power (cost, heat, sometimes better sound quality at lower volume levels) for occasional clipping - which you likely will never notice. There are many tradeoffs to be made when you design an amplifier. The designer will have to make these choices. It's not surprising that some people can hear differences between amplifiers under some conditions because different tradeoffs have been made with their design.


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## Sonnie

Wayne and I were just talking about trying to hear differences in different amps and both agreed that if I am going to spend $5,000 or $10,000 more on a an amp... it had better be more than any "subtle" difference. It had BETTER be a HUGE DRASTIC difference for that kind of money.

For this reason, it does not make sense to attempt long term listening tests. It would be terrible if I spent that kind of money on an amp to only learn over a 3-6 month period that the only differences were subtle. Of course if they are drastic... then surely I can notice that difference immediately without need for long term listening. A simply NON-blind listening test would suffice.

I can see spending a couple thousand on an amp to make sure I have enough power (and current) for speakers that might be more difficult to drive... but $14,000 for a pair of monoblocks like Zipser had... NO WAY! Put that money into better speakers, which can make a significant immediate improvement... not just a difference, but an actually improvement.

As Wayne and I have discovered with variance changes we have made in settings that effect the signal, while those changes make a difference, some better and some not... some are merely preference. So we have to determine... are the subtle changes an "improvement" or are they just "different". If I have to spend a considerable amount of money just for a subtle "difference" it doesn't make sense to me (strictly my opinion). If I only have to spend a little extra to get an "improvement" that might make more sense, depending on that improvement it makes, but it would also need to be an improvement that I could immediately hear in a simple comparison test.


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## AudiocRaver

Sonnie said:


> Wayne and I were just talking about trying to hear differences in different amps and both agreed that if I am going to spend $5,000 or $10,000 more on a an amp... it had better be more than any "subtle" difference. It had BETTER be a HUGE DRASTIC difference for that kind of money.
> 
> For this reason, it does not make sense to attempt long term listening tests. It would be terrible if I spent that kind of money on an amp to only learn over a 3-6 month period that the only differences were subtle. Of course if they are drastic... then surely I can notice that difference immediately without need for long term listening. A simply NON-blind listening test would suffice.
> 
> I can see spending a couple thousand on an amp to make sure I have enough power (and current) for speakers that might be more difficult to drive... but $14,000 for a pair of monoblocks like Zipser had... NO WAY! Put that money into better speakers, which can make a significant immediate improvement... not just a difference, but an actually improvement.
> 
> As Wayne and I have discovered with variance changes we have made in settings that effect the signal, while those changes make a difference, some better and some not... some are merely preference. So we have to determine... are the subtle changes an "improvement" or are they just "different". If I have to spend a considerable amount of money just for a subtle "difference" it doesn't make sense to me (strictly my opinion). If I only have to spend a little extra to get an "improvement" that might make more sense, depending on that improvement it makes, but it would also need to be an improvement that I could immediately hear in a simple comparison test.


There are different ways to chase improvement, and one can not help but refer to personality and psychological differences at some point. Those who are decisive - who hear differences and make choices in more black and white terms (Jung's "Judger") - the differences to be heard in making an equipment choice had better be significant, and they had better be obvious NOW (pretty safe assumption that Sonnie falls into this category). For a shades-of-gray person (Jung's "Perceiver"), the long-term process of discovering an incremental improvement can be fun - a process that would drive the more decisive listener nuts with frustration.


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## antoninus9

Sonnie said:


> Wayne and I were just talking about trying to hear differences in different amps and both agreed that if I am going to spend $5,000 or $10,000 more on a an amp... it had better be more than any "subtle" difference. It had BETTER be a HUGE DRASTIC difference for that kind of money.
> 
> For this reason, it does not make sense to attempt long term listening tests. It would be terrible if I spent that kind of money on an amp to only learn over a 3-6 month period that the only differences were subtle. Of course if they are drastic... then surely I can notice that difference immediately without need for long term listening. A simply NON-blind listening test would suffice.
> 
> I can see spending a couple thousand on an amp to make sure I have enough power (and current) for speakers that might be more difficult to drive... but $14,000 for a pair of monoblocks like Zipser had... NO WAY! Put that money into better speakers, which can make a significant immediate improvement... not just a difference, but an actually improvement.
> 
> As Wayne and I have discovered with variance changes we have made in settings that effect the signal, while those changes make a difference, some better and some not... some are merely preference. So we have to determine... are the subtle changes an "improvement" or are they just "different". If I have to spend a considerable amount of money just for a subtle "difference" it doesn't make sense to me (strictly my opinion). If I only have to spend a little extra to get an "improvement" that might make more sense, depending on that improvement it makes, but it would also need to be an improvement that I could immediately hear in a simple comparison test.


I agree.


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## vidiot33

antoninus9 said:


> I agree.


Yes, this is the most sensible answer. I would submit that good room treatments have a greater potential to effect a significant improvement than either amps or speakers...


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## Savjac

I am thinking that the financials that we are willing to put into a system will also tend to dictate how deep we wish to get into any and all differences we may experience howsoever minor or major. To me a $14,000 investment in monoblock amplifiers is nothing at all. I could as easily spend 14 grand on amplifiers as I could spend 2 million on a new Bigatti. NOTHING like this will ever happen, well at least not in this lifetime. 

C.G. Jung had a long talk with me before he passed and upon completion thereof he went into seclusion and wrote his manifesto on UFO's, although I have no clue why :huh:


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## chashint

vidiot33 said:


> Yes, this is the most sensible answer. I would submit that good room treatments have a greater potential to effect a significant improvement than either amps or speakers...


Meh.

Changing or adding speakers will always make an audible change to the sound.
Adding room treatments may make an audible change to the sound.
Changing or adding amplifiers seldom make an audible change to the sound.


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## padgman1

I think Sonny's and AudiocRaver's posts above succinctly sum up this thread......thank goodness I'm not much of a perceiver!!


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## Sonnie

Savjac said:


> C.G. Jung had a long talk with me before he passed and upon completion thereof he went into seclusion and wrote his manifesto on UFO's, although I have no clue why :huh:


So.... he went into seclusion upon completion of passing... makes sense. I guess if you believe he wrote something after passing, you might believe in UFO's. Oh wait... you have no idea why he passed, or why he went into seclusion (because he passed)... or why he wrote a manifesto on UFO's? Jack... are you an alien... or do you just like stealing cookies... or perhaps both? Are you sure you are even alive and not in seclusion with Jung... or we could all be in a matrix. :gulp:


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## Sonnie

padgman1 said:


> I think Sonny's and AudiocRaver's posts above succinctly sum up this thread......thank goodness I'm not much of a perceiver!!


And not being driven to nuts with frustration too, right?


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## Savjac

Sonnie said:


> So.... he went into seclusion upon completion of passing... makes sense. I guess if you believe he wrote something after passing, you might believe in UFO's. Oh wait... you have no idea why he passed, or why he went into seclusion (because he passed)... or why he wrote a manifesto on UFO's? Jack... are you an alien... or do you just like stealing cookies... or perhaps both? Are you sure you are even alive and not in seclusion with Jung... or we could all be in a matrix. :gulp:



Just Call me Mr. Anderson. 

I know what is going on here, I watch my cats and every now and then, they stare at the walls or ceiling. I know that they are uploading information to the mother ship. Yes I know this, Jung apparated one day whilst the cats were uploading and he gave me the secrets to stuff while increasing my Spidey Powers at the same time.

As far as cookies, it was the monsters own fault, he was waving it around and teasing us so I think I was in my right mind....or was it my left over mind...not sure, but either way, he taunted me into an act that I would have never tried before. I think this was a left over abandonment issue, although I was never really abandoned but that should not matter. 

Lastly, you assume Carl G. had passed before I became a child, well you would be mistaken, we communicated pshyoacoustically via short wave brain stuff two years before he moved on. So There !!


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## informel

AudiocRaver said:


> the long-term process of discovering an incremental improvement can be fun - a process that would drive the more decisive listener nuts with frustration.


How cannot you ear a difference immediately, you have to train your ear?
I think it is more like the brain that adapt, like when you listen to very loud music, after a while it does not sound so loud (the brain has an automatic gain control), also if you listen to heavy bass song and then listen to another type of music that has no bass content, it will sound thin for a little while (autoEQ of the brain).

It is like my wife's car, at first I tought the sound was terrible, but after a while I think it is not so bad, my brain had adapt to it


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## informel

I have to agree that if I spend 5K more I want a huge difference.
I watched the video from GIK and putting 5K on room acoustic would be a better investment if you have a dedicated room of course, I do not have one and do not think my wife would like to see big bass trap in the corner of the living room.


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## Almadacr

informel said:


> How cannot you ear a difference immediately, *you have to train your ear?*
> I think it is more like the brain that adapt, like when you listen to very loud music, after a while it does not sound so loud (the brain has an automatic gain control), also if you listen to heavy bass song and then listen to another type of music that has no bass content, it will sound thin for a little while (autoEQ of the brain).
> 
> It is like my wife's car, at first I tought the sound was terrible, but after a while I think it is not so bad, my brain had adapt to it


The same sentence can be ad to speaker manufacturers when they state that there speakers need 200 hours to break in .:rofl2:


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## antoninus9

There is, however, good reason to believe that even solid state electronics requires a warm-up period. My Tektronix oscilloscope takes about 20 minutes to produce accurate readings. I recently noticed in the user manual that it requires a 20 minute warm-up period from a cold start. Wish now that I had read the manual when I first got it. lol


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## Sonnie

informel said:


> It is like my wife's car, at first I tought the sound was terrible, but after a while I think it is not so bad, my brain had adapt to it


I bought one thinking it was pretty quiet when I got it... then several months later realized it was perhaps the loudest car I had every purchased. I am backwards.




informel said:


> I watched the video from GIK and putting 5K on room acoustic would be a better investment


Don't watch any expensive amp videos if they have that kind of effect on you. 

This is somewhat ironic though... as I see a lot of people treating their rooms for music listening... and we know a lot of studios treat their studio to improve the sound, yet I was reading a thread from another forum recently that was talking about my room for our speaker evaluations. One poster stated something to the effect that he would never evaluate two channel speakers in my room because it was over treated... treated for home theater and not two-channel. Another agreed. Of course they also said we did not have the speakers in the right place and the toe-in was way too much. I guess they know where every speaker should go in my room and exactly how they will sound. I have also done more to treat my room since we started our two-channel evaluations...and would not have it any other way... it certainly is not dead.... and I don't have any where close to $5K in it either.




Almadacr said:


> The same sentence can be ad to speaker manufacturers when they state that there speakers need 200 hours to break in .:rofl2:


Yeah... someone else said speaker break-in was nothing more than the speaker breaking us in over time.




antoninus9 said:


> There is, however, good reason to believe that even solid state electronics requires a warm-up period. My Tektronix oscilloscope takes about 20 minutes to produce accurate readings. I recently noticed in the user manual that it requires a 20 minute warm-up period from a cold start. Wish now that I had read the manual when I first got it. lol


Seems like a reasonably good point to warm up everything for 20-30 minutes before critical listening or testing.


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## antoninus9

I'm not in favor of testing home speakers in a treated room because it's not indicative of real world conditions, and can lead to confusion regarding the speakers.

All my speaker testing is done in an untreated room where the new speakers are compared to a known reference monitor such as the JBL 4412. This gives me a static baseline from which to evaluate the real world operational characteristics of a speaker system. I realize that this represents a minority perspective, but it's as close to objective as a subjective analysis can be.


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## Sonnie

This is a very large room... 19.5' wide by 23.5' deep... so we are basically treating first reflections. When you pull the speakers out into a room this large, you take more of the boundaries out of play. 

Either way, I promise you we are in the real world here... and there are a LOT of members who will be reading our event who have treated rooms. I think our conditions could represent a good portion of how critical listeners listen.

One thing we have stressed is if you are going to spend good money on speakers, make sure you can set them up for the best listening experience... make sure you can pull them out from the wall and get best placement if that is what is needed. Make sure you can treat the room if that is what is needed. If we take all these treatments down in my room, then we miss out on the best sound we can obtain. We start getting a bunch of reflections that mar the sound and keep us from hearing what we are suppose to hear.


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## Sonnie

Well... it has been done! We heard a difference between two amps tonight. It took a sinewave for me to be able to hear it, but Wayne could clearly pick it out... and identify the amp that was different (I think he missed it one time out of 40-50 switches that I was making). Strangely enough it was only on one song that it could be identified. I could not hear it myself with any music... and I feel like it could be something that might very well get by others too, simply because it is extremely subtle... and does not occur on all music.

BUT... no reason to get too excited, it was merely distortion that he was hearing, although not from clipping/over-driving the amp. My best guess is that it is either a defective amp or a poorly designed amp that is introducing distortion into the signal for some reason. The amp (Behringer A500) also had a pretty serious low cycle hum and buzzing that was very noticeable at lower volumes. This could have had something to do with the distorted sound... possibly exciting some frequencies more than others. It is hard to say. Wayne will share a better explanation later.

Of course I have never claimed I could not hear a difference between an amp that was distorting the signal and an amp that was not (I always figured I would be able to hear it)... YET, I have to admit, I could not hear it in this case, unless I used a sinewave signal. I suppose it depends on how much the sound is distorted as to whether or not I would hear it, plus it may depend on whether or not I am intentionally trying to listen out for the distortion.

This did not effect soundstage, imaging or the frequency response, but we could measure it with REW and see it in the distortion plots. Again, Wayne can share those graphs later.

We could NOT hear any differences between the Emotiva XPR-5 vs. the Behringer EP2500 or the Anthem Integrated 225. We did not get to try the Crown because we could not get them level matched. Leonard is suppose to bring in a few more amps during the event and hopefully we can take a few minutes to test those too.


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## Savjac

Well, there you have it, an idea is born. 

In all seriousness, thank you for doing alll this Sonnie and Wayne, alot of learning can be had from these tests, and I am glad now that I did not have to drive down there and velcro your bottom to the chair until you heard the truth. Not having a steady job gives me hall monitor time young man so toe that line from now on,

Never the less, thank you for the information, well done.


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## Mike0206

I had heard something similar to what you experienced Sonnie. There are amps that can distort with certain harmonics. Perhaps the 100-200hz range produces some distortion in that area and so although the amp isn't clipping necessarily, one amp can have more distortion at a specific harmonic order as opposed to another amp and that can be audible. But as you pointed out, very hard to hear with music. Usually requires a steady test signal.


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## antoninus9

Sonnie said:


> This is a very large room... 19.5' wide by 23.5' deep... so we are basically treating first reflections. When you pull the speakers out into a room this large, you take more of the boundaries out of play.
> 
> Either way, I promise you we are in the real world here... and there are a LOT of members who will be reading our event who have treated rooms. I think our conditions could represent a good portion of how critical listeners listen.
> 
> One thing we have stressed is if you are going to spend good money on speakers, make sure you can set them up for the best listening experience... make sure you can pull them out from the wall and get best placement if that is what is needed. Make sure you can treat the room if that is what is needed. If we take all these treatments down in my room, then we miss out on the best sound we can obtain. We start getting a bunch of reflections that mar the sound and keep us from hearing what we are suppose to hear.


Agreed, "critical listeners" may have treated rooms, but they represent a tiny minority of the overall enthusiast community. Most either can't afford a specialized listening room or they face the wife factor.

I have three rooms available: listening room, live room, and ultra-live room with hardwood floors and cathedral ceiling. My wife is tolerant of my hobby and even offers her own input. 

A speaker system that sounds wonderful in a listening room, all too often falls apart in the average living room. Only diverse testing can reveal these problems. This experience has allowed me to help many people find speaker systems that are well suited to their particular listening environment. 

For me, it's one of the little pleasures in life to see others enjoy truly great sound without having to take on a second mortgage.


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## ajinfla

informel said:


> How cannot you ear a difference immediately, you have to train your ear?


Sometimes, yes.
Training can not only allow for detection of what may be missed, but also quicker detection, due to familiarity of what to listen for (via training).
http://seanolive.blogspot.com/2008/12/loudspeaker-preferences-of-trained.html

However....



informel said:


> I think it is more like the brain that adapt


Yes!! Very much so. We are constantly in adaptation mode, from the moment we enter a room, start hearing sounds...

http://www.davidgriesinger.com/binaural_hearing.ppt

It is with great amusement that I read audiophile tales of "break in" and "burn in", etc. 

cheers


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## ajinfla

Sonnie said:


> This is somewhat ironic though... as I see a lot of people treating their rooms for music listening... and we know a lot of studios treat their studio to improve the sound, yet I was reading a thread from another forum recently that was talking about my room for our speaker evaluations. One poster stated something to the effect that he would never evaluate two channel speakers in my room because it was over treated... treated for home theater and not two-channel. Another agreed.


I chimed in on that thread. What I said was, the same "treatment" that mitigates (to one extent) the poor off axis of the poor off axis speaker, may be the bane of the speaker with the good off axis.
Studiophiles suffer from the same maladies as audiophiles. A little "treatment" is good, so a lot is better. 
Funny things happen when both are subjected to blind testing though....



Sonnie said:


> I have also done more to treat my room since we started our two-channel evaluations...and would not have it any other way... it certainly is not dead.... and I don't have any where close to $5K in it either.


As I have said for years, one mans "treated" room is another "Iso ward" .
Know exactly what it is you are "treating", else you might be creating a problem for a solution, rather than vice versa. 
As always, YMMV.

cheers


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## gdstupak

antoninus9 said:


> I'm not in favor of testing home speakers in a treated room because it's not indicative of real world conditions...All my speaker testing is done in an untreated room where the new speakers are compared to a known reference monitor such as the JBL 4412. This gives me a static baseline from which to evaluate the real world operational characteristics of a speaker system.


This makes sense if the speakers being tested are going to be used in that room alone. But if you're testing speakers that will be used in different rooms, then the baseline is going to be different from all other untreated rooms because you are listening to how the speakers react with the room, and all rooms sound different when untreated.


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## Sonnie

The more I think about it, the more inane it seems though... someone judging how speakers will sound in my room based on my equipment, my treatment, speaker placement and toe-in... and they have never been here to hear the first song. Amazing telepathy!

Obviously he never bothered to read the full reviews by four different guys who have listened to speakers in hundreds of rooms (combined from various homes and audio shows)... some treated and some not... with all kinds of different equipment. 

No doubt he has never done any A/B amp testing.

But hey... in the end he did admit he was a snob. :heehee:


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## antoninus9

gdstupak said:


> This makes sense if the speakers being tested are going to be used in that room alone. But if you're testing speakers that will be used in different rooms, then the baseline is going to be different from all other untreated rooms because you are listening to how the speakers react with the room, and all rooms sound different when untreated.


True, but I use three different rooms in testing. Please see above. It's a way of testing real world conditions that the average homeowner might experience. I can also vary placement, etc. to better judge how a given speaker might respond in a given room. 

It works quite well at predicting and solving audio problems the average user might encounter.

There are various possible scenarios: open air (outside), large cathedral-like rooms, small carpeted living rooms, etc. Over time you will see certain trends developing among various driver configurations. For instance electrostats are poor outdoors while horns reinforced with large low frequency cones excel.


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## Mike0206

Treated or not treated the best way to feel comfortable about a purchase is to take advantage of the 30-45 day in home trials to audition the speakers in YOUR specific environment before making a purchase you can't live with. Now these evaluations are great for the consumer cause it could weed out the inferior products in a specific category or price point. But in no way should somebody purchase something based solely on somebody else's evaluation. Listen for yourself and definitely take into consideration the opinions of others but don't let that alone make up your mind on what speakers you are going to purchase or processor, amp etc.......


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## Architect7

For me, I don't think there is a reliable difference between amps, all other variables held constant. However, this is hard to reproduce in the real world and the sum of the parts will create subtle differences that can be apparent in certain situations.

I've also found that I can keep my psychoacoustic bias in check with the presence of a fellow audiophile. This has given me a self-conscious perspective that helps neutralize bias and expose objectivity.


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## Almadacr

Sonnie said:


> The more I think about it, the more inane it seems though... someone judging how speakers will sound in my room based on my equipment, my treatment, speaker placement and toe-in... and they have never been here to hear the first song. Amazing telepathy!
> 
> Obviously he never bothered to read the full reviews by four different guys who have listened to speakers in hundreds of rooms (combined from various homes and audio shows)... some treated and some not... with all kinds of different equipment.
> 
> No doubt he has never done any A/B amp testing.
> 
> But hey... in the end he did admit he was a snob. :heehee:


Well it's the internet era Sonnie , and anyone can say what ever they say because they hide behind a screen and read it somewhere . IMO after choosing speakers one of the most important upgrades is room acoustics . In another forum i had one guy who said to me that he changed banana plugs and it improved his sound :yikes: .


----------



## ajinfla

Almadacr said:


> IMO after choosing speakers one of the most important upgrades is room acoustics.


They are intertwined. The speaker (design) choices, will to a large extent, dictate the "room" acoustics. Just like one should decide on an amplifier...based on the load it will be driving. Tastes of course, vary. More so sighted and by what is believed/expected.



Almadacr said:


> In another forum i had one guy who said to me that he changed banana plugs and it improved his sound :yikes: .


All sorts of strange beliefs in this hobby. 

cheers


----------



## Sonnie

Yeah... the world would be dull with our this hobby, strange beliefs, bananas and AJ. :whistling:

Okay... sorry I took the thread off topic with the speakers and whatever else I said... oh bananas and AJ. :dontknow:

Anyway... back on topic to differences in amps. :T

Although it does seem like we have beat it to death with fifty-eleven opinions.


----------



## Savjac

Sonnie said:


> Yeah... the world would be dull with our this hobby, strange beliefs, bananas and AJ. :whistling: Okay... sorry I took the thread off topic with the speakers and whatever else I said... oh bananas and AJ. :dontknow: Anyway... back on topic to differences in amps. :T Although it does seem like we have beat it to death with fifty-eleven opinions.


Banana's and AJ, quite the grouping indeed. 

But have you checked the substantial difference in speaker cables ? 

Maybe I should go to my corner now.


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## ajinfla

Sonnie said:


> Anyway... back on topic to differences in amps. :T


Indeed. Which is why I advised, pick your amp based on load and desired sound pressures.
It might affect the differences you "hear" between amps.


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## NBPk402

ajinfla said:


> Indeed. Which is why I advised, pick your amp based on load and desired sound pressures.
> It might affect the differences you "hear" between amps.


Is that because most amplifiers have their lowest distortion at about 2/3 of rated full power?


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## ajinfla

No, it's because the combination of load and desired drive levels/SPLs, will largely determine whether the amplifier misbehaves to the point of becoming audible, i.e. you actually "hear" the amplifier.
Otherwise, there is nothing to "hear" about voltage or current multiplication.

cheers


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## Sonnie

That is a very good point... I have not really thought of it that way. Of course I have stated several times an amp should be neutral, but not being able to "hear it" is a good way of saying it.


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## lcaillo

Sonnie said:


> Well... it has been done! We heard a difference between two amps tonight. It took a sinewave for me to be able to hear it, but Wayne could clearly pick it out... and identify the amp that was different (I think he missed it one time out of 40-50 switches that I was making). Strangely enough it was only on one song that it could be identified. I could not hear it myself with any music... and I feel like it could be something that might very well get by others too, simply because it is extremely subtle... and does not occur on all music.
> 
> BUT... no reason to get too excited, it was merely distortion that he was hearing, although not from clipping/over-driving the amp. My best guess is that it is either a defective amp or a poorly designed amp that is introducing distortion into the signal for some reason. The amp (Behringer A500) also had a pretty serious low cycle hum and buzzing that was very noticeable at lower volumes. This could have had something to do with the distorted sound... possibly exciting some frequencies more than others. It is hard to say. Wayne will share a better explanation later.
> 
> Of course I have never claimed I could not hear a difference between an amp that was distorting the signal and an amp that was not (I always figured I would be able to hear it)... YET, I have to admit, I could not hear it in this case, unless I used a sinewave signal. I suppose it depends on how much the sound is distorted as to whether or not I would hear it, plus it may depend on whether or not I am intentionally trying to listen out for the distortion.
> 
> This did not effect soundstage, imaging or the frequency response, but we could measure it with REW and see it in the distortion plots. Again, Wayne can share those graphs later.
> 
> We could NOT hear any differences between the Emotiva XPR-5 vs. the Behringer EP2500 or the Anthem Integrated 225. We did not get to try the Crown because we could not get them level matched. Leonard is suppose to bring in a few more amps during the event and hopefully we can take a few minutes to test those too.


Sure. I have my Adcom and my B&K. I am thinking I am also going to bring a scope so we can make careful meadurements. Long ago I did some amp testing running sweeps at different levels into real speakers, noting the frequency response at each level at the output of the amp while driving a real load. What I found was surprisingly different linearity (or a lack thereof) in some amps into some loads. This was 25 years ago, and I suspect that amps have improved considerably, but it would be interesting to see.

Also, a quick check to identify some distortions (like what you identified earlier in the thread) is to look at a squre wave output of an amp. DAngerous into a speaker other than at low levels, but if I can recover my 4 and 8 ohm test load resistor banks from a tech friend of mine, we can look at some of that as well as harmonics on sine waves. I have the amp switcher for easy comparisons as well.


----------



## antoninus9

I apologize for getting off topic.


----------



## Sonnie

We could see the various distortion harmonics via REW. Wayne will post those in his explanation.


----------



## Savjac

What I am gathering here is that there may be some minor differences and at this time y'all are trying to quantify those possible differences in an effort to maybe point to some issues in design that may be reflected in what we hear.

Sounds like a good thing to me, it would be nice to put numbers to some things and maybe a chart or graph could be made over time.


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## Sonnie

No... we clearly no what the difference is... it is distortion... and we know exactly what frequencies the distortion exist.

And again... no one has ever claimed they could not hear a difference in amps if one had audible distortion and one did not... although in this case it was not audible to me with music (a compliment to Wayne's golden ears)... it took a sinewave for me to hear it... and then it was truly difficult for me to hear it, but I did. I think we have always kicked poorly designed amps to the curb too... and we may have very well discovered one of those.

What is odd about this distortion is it is not created by over-driving the amp... and it could NOT be heard in every song. Actually at this point, only one song (and possibly only a portion of the song). That does not mean it can't be heard in other songs by some people. I believe Wayne is going to attempt to reach out to owners of the Behringer A500 and see if they can hear the distortion with this clip of music (or any other music). He has two A500 amps and both have this distortion on at least that one song.

One thing that I clearly noticed from the listening position was the amount of buzz/hum from the amp. I don't know that this correlates in any way to the distortion, since the distortion was only at certain frequencies. Wayne can connect his other A500 at home (I still have this one here for future testing)... and see if his has the buzz/hum. If it does not, then we can eliminate this having any correlation to the distortion.

Despite Wayne having two of these with this distortion, we have no idea if it is a run of defective amps... or if it is merely a poor design on Behringer's part. The EP2500 does not exhibit this distortion, so we do know it is not common among all Behringer amps. 

Anyone that claims they hear a difference in an amp and the difference sounds like distortion, they should be able to identify if it is actually distortion with REW.

This is really quite different than most of the claims we hear describing differences in amps, such as wider soundstage, deep soundstage, more precise imaging, better imaging, more air between notes, warmer, brighter, more or less forward, darker, more or less presence, better bass, more rounded bass, solid bass, tighter bass, more prominent midrange, laid back midrange... and any number of other descriptive sonic characteristics that are 100% dismissed by blind AB testing. HOWEVER... you could say that one amp has more "clarity" than another amp if one amp is clean and the other one has audible distortion and it is not being over-driven. HOWEVER AGAIN... in our case... and I suggest likely in most cases, this is something that is identifiable and measurable. Also, outside of tube amps, I have not known any solid state amp companies to intentionally add distortion to their amps... although I suppose there could be some that do that.


----------



## lcaillo

A buzz or hum could be a power supply cap going bad, which could seriously limit the current available. We can test it if I get my loads back.


----------



## nova

Interesting as I am one that claims my speakers sound better with a good amp like my Acurus A250. Of course my belief is that they sound better because the amp controls the 12" woofer better than the Denon 3805. IMO they keep moving after the signal has stopped which causes ringing and is amplified by the aluminum material the drivers are made of. So the better amp has a higher damping factor, controls the driver better and produces better sound. Or am I just totally off my rocker?


----------



## Savjac

I understand, actually I did before but did not present it properly in my post.

Having been a part of this discussion for some time and maybe actually a less than stellar poster, even I admit without qualifications, the while I believe I have heard some differences, and as mentioned, they were minor indeed, I would like to go back to some extent and say I do not feel that one should put too much emphasis on the amplification part of the chain as in reality, if it is of sufficient build and has sufficient power to drive the speakers hooked to it, then maybe that is they way it should be.

Over the last few months, I have been on a personal journey in an attempt to wring out the different parts of an audio system so that I can zoom in on what causes me the most problems. The Amplifier has been a put in place, turn it on and keep it clean category. I have played with a few others in this course but have not felt any need to change, and this includes smaller tube amps. I am guessing in my quest for the perfect truth, I may have over stayed my belief that all things may have equal importance when it comes to sound reproduction. I do tend to believe that speakers and the room hold the greatest weight in the sound system equation with but one of these two getting the most attention. I am pulling my room apart now to address this very situation. So maybe becoming involved in this thread has taught me more than something about one item, but rather, something about a System in harmony. 

I started listening to music a good bit in the late 60's and got myself involved a bit deeper in the late 70's after returning from "Over There" and subsequently finishing with college. I am not bragging I am just kind of admitting that sometimes we maybe take things too serious and forget the fun we are supposed to be having. I want to get back to that time and place today, drop a tune in some form of player, turn on the amplification and get transported, without drugs, to another place for 45 minutes or so and for once in many years, FORGET to listen for proper tonality, soundstage etc and just bathe in the music before me.

Is that still possible ?? Or can we be too jaded.


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## Sonnie

I don't think it is possible without the drugs. 

The drugs being the experience!

Wayne and I talk about that all the time... this hobby IS our drug. The fun we have... the testing... the event... it IS our drug. 

I know there have been comments in leading up to our events... "And people do drugs?"


----------



## Sonnie

nova said:


> Interesting as I am one that claims my speakers sound better with a good amp like my Acurus A250. Of course my belief is that they sound better because the amp controls the 12" woofer better than the Denon 3805. IMO they keep moving after the signal has stopped which causes ringing and is amplified by the aluminum material the drivers are made of. So the better amp has a higher damping factor, controls the driver better and produces better sound. Or am I just totally off my rocker?


Absolutely... you have lost your marbles man... what has gotten into you... you are going crazy? lol

You may very well be hearing a difference. I (and others) have never claimed there are not differences between amps (yet some might stand firm with that claim)... instead we have doubted it because all the testing done thus far has proven there is not. We generally suggest that it is our mind, biases and other things playing tricks on us... since the proof has been so overwhelming. Of course we have been trying to hear a difference such as you describe, but we just haven't done it yet... although we have only tested a handful of amps so far.

I would definitely think the 3805 would give out quicker than the A250, especially with less efficient speakers.

If you had a way to A/B test the two, you might be able to positively identify the difference... or you may surprise yourself. I believe ringing is something REW can measure too, so you might run some sweeps with both at varying levels and see if you can see it. If you can see it, you might well be able to hear it. :huh:


----------



## Savjac

Sonnie said:


> I don't think it is possible without the drugs.
> 
> The drugs being the experience!
> 
> Wayne and I talk about that all the time... this hobby IS our drug. The fun we have... the testing... the event... it IS our drug.
> 
> I know there have been comments in leading up to our events... "And people do drugs?"



Too True !!
There is an addictive quality to this, good or bad, it may be worse than drugs. :yikes:


----------



## 3dbinCanada

My stance is if the speakers being powered is easily driven by the weakest amp in a comparison and can fill that room without going to the weaker's amps limit, then one would be very hard pressed to hear the difference in a SBT listening test. Only when one begins to encroach the design limits of the weaker amp does the difference become apparent.


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## AudiocRaver

informel said:


> How cannot you ear a difference immediately, you have to train your ear?
> I think it is more like the brain that adapt, like when you listen to very loud music, after a while it does not sound so loud (the brain has an automatic gain control), also if you listen to heavy bass song and then listen to another type of music that has no bass content, it will sound thin for a little while (autoEQ of the brain).


Where a difference in sound is more dramatic, it would probably be heard immediately. Where the difference is subtle, it might only be easy to hear with with a certain kind of music that allows it to stand out.


----------



## Sonnie

Case in point, I could not hear the distortion that Wayne heard when listening to music. That tells me that there could be other subtle differences that I can not hear that someone else might, although we haven't run into any of those differences typically described by most as differences.


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## lcaillo

What is ignored as a variable in much research, because it is very hard to isolate, are individual differences in perception. This is why it takes such large sample sizes to find statistically significant differences. I have always said that we should focus research on those that claim to hear differences and try to find reasons why, either psychological or physical.

The problem is that those who do hear differences are hard to get into objective studies. Perhaps Wayne is our best test subject. He obviously has a very consistent and well trained ear, based on the listening sessions that we have shared so far.


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## antoninus9

It sounds to me like you may be getting some AC into the circuit. Bad caps are a possibility.

Does that amp have a three prong plug? If so, try using a converter to a two prong and see if it fixes the problem.


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## lcaillo

Defeating ground is never a good solution, though it can be useful in identifying a ground loop issue, as a start anyway. If there is a ground loop problem the system design and connections need to be tested. In Sonnie's system I doubt that is the case. Much more likely a bad amp. We will test it to be sure.


----------



## chashint

Sonnie said:


> Case in point, I could not hear the distortion that Wayne heard when listening to music. That tells me that there could be other subtle differences that I can not hear that someone else might, although we haven't run into any of those differences typically described by most as differences.


I may keep this on mind for future reference as I peruse your speaker reviews. 
......just messing with ya...


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## Sonnie

Actually you should! I can guarantee you Wayne, Leonard and Joe got better ears than I do. I have only done critical music listening for 6-8 months now... at least as critical as we have been reviewing them... and my continue long term listening since these events started. Prior to this, I hardly ever listened to music.


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## Savjac

Like everything else, it takes time, some training and lots of listening to hear differences, if there are any. Once heard however, it is very easy to hear again. So like most things in life, we may not even know what we are experiencing until either someone demonstrates it or, in this case it becomes very apparent.


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## lcaillo

Experience is a tricky thing. Just the suggestion that there are differences to hear can affect one's perception. I think once someone identifies a difference, we need to focus on explaining that difference. We have lots of analytical tools today that were not even possible 20 years ago.


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## AudiocRaver

Sonnie said:


> Well... it has been done! We heard a difference between two amps tonight. It took a sinewave for me to be able to hear it, but Wayne could clearly pick it out... and identify the amp that was different (I think he missed it one time out of 40-50 switches that I was making). Strangely enough it was only on one song that it could be identified. I could not hear it myself with any music... and I feel like it could be something that might very well get by others too, simply because it is extremely subtle... and does not occur on all music.


One of the projects undertaken last week at Sonnie's place was amplifier A-B test comparisons. We started the amplifier comparison session with a number of repeating test loop tracks. A track consisted of 15 repetitions of a segment of a familiar song, each repetition 15 to 20 seconds long, making it easy to switch back & forth between amps and hear the same music played on the two amps just seconds apart.

We compared the Emotiva XPR-5 with the Behringer EP2500 for about 20 minutes. We heard no difference.

We compared the Emotiva XPR-5 with the Anthem Integrated 225. We heard no difference.

When we compared the Emotiva XPR-5 with the Behringer A500, I could hear a difference on one loop, the pulsing synthesizer intro to Porcupine Tree's _Deadwing._ I had heard it before. I have two of these amps and have been using them for about 5 years with different speakers, very satisfactorily, except during the opening of that one song. There are probably other tracks that I could find where I could hear that distortion if I went questing to find them, I just never have.

Anyway, I came armed with a loop of that part of that track, and could hear the distortion very clearly (I could hear it during the REW sweep, too). With a sine wave at I forget what frequency, switching back and forth between the clean XPR-5 and the distorting Behringer A500, Sonnie could hear it, too.

Here is a plot of the distortion we were hearing. It is probably crossover distortion, all 3rd harmonic distortion. Higher odd-order harmonics were slightly elevated, even-order harmonics were not elevated at all. (Only 2nd harmonic - red, third harmonic - orange, and THD - black - are shown. It is a measurement taken with the Paradigm Studio 60's, so the "floor" is speaker distortion.) Actually, the loop we were listening to was probably playing about 10 dB lower. If we were to run a REW sweep at a lower level, it would probably show distortion in the 3% to 5% range. What is shown below amounts to distortion in the 1% to 3% range.

 

By the way, that was the only track on which we heard any difference between those two amps.



> BUT... no reason to get too excited, it was merely distortion that he was hearing, although not from clipping/over-driving the amp. My best guess is that it is either a defective amp or a poorly designed amp that is introducing distortion into the signal for some reason. The amp (Behringer A500) also had a pretty serious low cycle hum and buzzing that was very noticeable at lower volumes. This could have had something to do with the distorted sound... possibly exciting some frequencies more than others. It is hard to say. Wayne will share a better explanation later.
> 
> Of course I have never claimed I could not hear a difference between an amp that was distorting the signal and an amp that was not (I always figured I would be able to hear it)... YET, I have to admit, I could not hear it in this case, unless I used a sinewave signal. I suppose it depends on how much the sound is distorted as to whether or not I would hear it, plus it may depend on whether or not I am intentionally trying to listen out for the distortion.
> 
> This did not effect soundstage, imaging or the frequency response, but we could measure it with REW and see it in the distortion plots. Again, Wayne can share those graphs later.
> 
> We could NOT hear any differences between the Emotiva XPR-5 vs. the Behringer EP2500 or the Anthem Integrated 225. We did not get to try the Crown because we could not get them level matched. Leonard is suppose to bring in a few more amps during the event and hopefully we can take a few minutes to test those too.


Sonnie and I had a discussion about what qualifies as a "different sounding amp" and what does not. It got me wondering if we all even agree on basic terms and conditions. Here are a few questions to consider:

Is an _audible difference between amps_ one that is necessarily heard immediately regardless of the music or does it sometimes only show up on certain parts of certain tracks or only occasionally?
When we talk about an _audible difference between amps_, are we strictly talking about sonics, the part of the experience that humans hear with the auditory senses? If so, then there must be a difference in the waveforms coming out of the amp outputs, must there not? If that is true, there would have to be some way of showing or measuring that difference, if not by conventional measurements, at least by comparing waveform details directly, would there not?
Could an _audible difference between amps_ sometimes be a form of distortion that is subtle enough not to be readily identifiable as such? Or a distortion that only is audible occasionally?
Perhaps some more detailed discussion of terms and conditions is in order.


----------



## AudiocRaver

As Sonnie already posted - somewhere - he devised a way to switch between hearing his Oppo player's DACs at work vs. hearing his Onkyo preamp's DACs at work. We both gave the two quite a good listen for close to 30 to 40 minutes. Neither of us could hear any difference.

And we barely got our feet wet listening to a 24/192 track (from HDtracks) carefully shortened and rendered to 24/192, 24/96, 24/48, and 16/44. We could not tell any difference, but did not have good comparison sequences set up for a decent test and were not able to spend much time on it. (We will have better tests set up for our February speaker event.) At first, the tracks were played from USB memory stick by the Oppo player via optical link to the Onkyo preamp. We ran into one snag: Some part of the signal chain did not like the 24/192 tracks (neither our re-rendered WAV versions nor the original unshortened FLAC version), and only gave us jerky distorted bare-recognizable junk. Anyone run into that before? Analog out from Oppo into Onkyo worked fine.

More work to be done here.:bigsmile:


----------



## Architect7

AudiocRaver said:


> As Sonnie already posted - somewhere - he devised a way to switch between hearing his Oppo player's DACs at work vs. hearing his Onkyo preamp's DACs at work. We both gave the two quite a good listen for close to 30 to 40 minutes. Neither of us could hear any difference.
> 
> And we barely got our feet wet listening to a 24/192 track (from HDtracks) carefully shortened and rendered to 24/192, 24/96, 24/48, and 16/44. We could not tell any difference, but did not have good comparison sequences set up for a decent test and were not able to spend much time on it. (We will have better tests set up for our February speaker event.) At first, the tracks were played from USB memory stick by the Oppo player via optical link to the Onkyo preamp. We ran into one snag: Some part of the signal chain did not like the 24/192 tracks (neither our re-rendered WAV versions nor the original unshortened FLAC version), and only gave us jerky distorted bare-recognizable junk. Anyone run into that before? Analog out from Oppo into Onkyo worked fine.
> 
> More work to be done here.:bigsmile:


Might have been the issue discussed in the link below combined with a clock that was off, maybe?

http://xiph.org/~xiphmont/demo/neil-young.html


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## Sonnie

I saw that posted somewhere else... and I believe it may have ruffled a few feathers. 

Actually this is the third time it has been posted here in this thread from April 2013 to this month.

Interesting read... and our test somewhat confirmed that 192 did sound worse via optical between the OPPO and ONKYO.


----------



## AudiocRaver

Thanks for the link. It is an interesting read. While there is lots of good information, there is also a tendency common to the writings of "mythbusters." That tendency is to state the limits of human capacity in terms of absolute hard boundaries rather than in terms of statistically derived averages (means), and to therefore assume that extra bandwidth or resolution or whatever can never be appreciated by anyone.

I have a skeptical side, too, but - being a shades of gray kind of guy at heart - am open to the _possibility_ that exceptions can exist to any limitation. Getting proof is the hard part.:bigsmile:


----------



## robbo266317

With the advent of digital processing this has taken taken a whole new look at the issue!

Back in my day lddude: it was simply about how the amp sounded, now it is the whole chain! including the receivers DAC's and frequency compensation. :dizzy:


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## lcaillo

It is still your day, old man! Don't make us all old!


----------



## antoninus9

AudiocRaver said:


> Here are a few questions to consider:
> 
> Could an _audible difference between amps_ sometimes be a form of distortion that is subtle enough not to be readily identifiable as such? Or a distortion that only is audible occasionally?
> Perhaps some more detailed discussion of terms and conditions is in order.


Envelope delay is a distortion, but to some it's preferable. 

By the time a source signal reaches an amplifier it has already been distorted by the recording and equalization process. I think an important aspect of this argument is what causes certain forms of distortion to be preferable, and others not so.

I believe that the supposed differences between solid state amps is directly related to dynamics. As the voice coil of a speaker moves it causes variances in impedance. This seems to translate into rapidly occurring changes in dynamics within the equalization curve. A higher current/high dampening amp may appear to sound "brighter" with some music, while one with lesser current and dampening may seem neutral or warm. These differences may only be audible when combined with certain pieces of music and speaker systems. 

I'm not sure how you could measure such subtle and fast peaks across the spectrum. If it's a relationship between impedance/dynamics, you would have to know which frequencies are impacted on a given recording, and then determine the impedance of the system within a millisecond of the occurrence. 

In any case all of these are very subtle and random. Properly functioning solid state amps should sound virtually identical to one another.


----------



## Savjac

Sonnie said:


> I saw that posted somewhere else... and I believe it may have ruffled a few feathers.
> 
> Actually this is the third time it has been posted here in this thread from April 2013 to this month.
> 
> Interesting read... and our test somewhat confirmed that 192 did sound worse via optical between the OPPO and ONKYO.


I do not like that guys writing or video, too condescending and I think his mind is made up irrespective of truth. Maybe like most of us. :dontknow:

None the less, you may have actually found a difference that is something many of us have noted, that optical, for whatever reason, may NOT be the best way to transmit digital audio. There is something to the claims that Toshiba, the inventor of the Toslink is going to stop making the components in the near future. It appears that the constructor in the source and deconstructor in the receiver are both about $2 each and no longer can be considered quality units. It is my understanding that USB and/or Coax at the cables to use if transporting digits from one unit to another. 
I have heard issues with the Toslink that has caused me to move to another interconnect, but not on ALL components, so its kind of weird actually. 

None the less, you heard a difference and that is very AWESOME !!!!:jump:


----------



## antoninus9

Is there already a thread somewhere that discusses TOSLINK vs. HDMI vs. USB? If not, there should be because there's a lot of conflicting information about these.


----------



## ajinfla

Savjac said:


> I do not like that guys writing or video, too condescending and I think his mind is made up irrespective of truth. Maybe like most of us. :dontknow:


Hi Jack,

Regardless of how you perceive the person, logic dictates that you focus only on his argument, not him. He/the article is on solid ground there. Barring valid, contradictory evidence?



Savjac said:


> None the less, you may have actually found a difference that is something many of us have noted, that optical, for whatever reason, may NOT be the best way to transmit digital audio. There is something to the claims that Toshiba, the inventor of the Toslink is going to stop making the components in the near future. It appears that the constructor in the source and deconstructor in the receiver are both about $2 each and no longer can be considered quality units. It is my understanding that USB and/or Coax at the cables to use if transporting digits from one unit to another.
> I have heard issues with the Toslink that has caused me to move to another interconnect, but not on ALL components, so its kind of weird actually.
> 
> None the less, you heard a difference and that is very AWESOME !!!!:jump:


I am not aware any issues with optical transmission of digital signals in audio (they seem to work just fine for data used by the military, Verizon, etc, etc.). Can you provide some science related links, or are these "problems" of the audiophile variety?
In any case, perhaps a thread about "audiophile drama involving digital" is more appropriate than a "hearing" amplifiers thread?? 
My 2c

cheers


----------



## AudiocRaver

AudiocRaver said:


> And we barely got our feet wet listening to a 24/192 track (from HDtracks) carefully shortened and rendered to 24/192, 24/96, 24/48, and 16/44. We could not tell any difference, but did not have good comparison sequences set up for a decent test and were not able to spend much time on it. (We will have better tests set up for our February speaker event.) At first, the tracks were played from USB memory stick by the Oppo player via optical link to the Onkyo preamp. We ran into one snag: Some part of the signal chain did not like the 24/192 tracks (neither our re-rendered WAV versions nor the original unshortened FLAC version), and only gave us jerky distorted bare-recognizable junk. Anyone run into that before? Analog out from Oppo into Onkyo worked fine.





Architect7 said:


> Might have been the issue discussed in the link below combined with a clock that was off, maybe?
> 
> http://xiph.org/~xiphmont/demo/neil-young.html


For the sake of clarity, what we heard with that track at 24/192 over optical from the OPPO was not IM distortion, it was "digitally-mangled-barely-recognizable" distortion of a link not working properly.


----------



## Sonnie

Yep... I heard differences, but not the kind I was hoping to hear.

I want to be able to hear that "dark tonality" that a few have mentioned. 

Can you describe exactly what is meant by "dark tonality". If a tone changes, does that mean a particular frequency range changed?

This among other changes I would like to be able to hear. I don't want the difference to be due to distortion.


----------



## Sonnie

AudiocRaver said:


> For the sake of clarity, what we heard with that track at 24/192 over optical from the OPPO was not IM distortion, it was "digitally-mangled-barely-recognizable" distortion of a link not working properly.


I sounded like a seriously bad cell phone connecting with only part of the signal getting through.

I wanted to start the ole saying... "Can you hear me now?... Can you hear me now?" 

If my memory serves me correct, there were a few tracks we could hardly get even the occasional sputter. 

I wonder if it could be the DAC in the Onkyo having issues with it, although it is supposed to be able to handle up to 192/32.


----------



## antoninus9

I was able to reproduce a dark tonality using J. River. It was directly related to setup.

On my system I cannot detect any different between HDMI, Coax and TOSLINK so long as they are used with ASIO or WASAPI in bit-steaming mode. They seem to all deliver an identical bit-stream to the DAC.

However, this may not be the case for everyone. There are a few variables between components that could account for what some are experiencing.


----------



## AudiocRaver

Sonnie said:


> I sounded like a seriously bad cell phone connecting with only part of the signal getting through.
> 
> I wanted to start the ole saying... "Can you hear me now?... Can you hear me now?"
> 
> If my memory serves me correct, there were a few tracks we could hardly get even the occasional sputter.
> 
> I wonder if it could be the DAC in the Onkyo having issues with it, although it is supposed to be able to handle up to 192/32.


More for clarity on the 24/192 optical issue:

The original downloaded track was a FLAC. A shortened version of that was rendered to 24/192 WAV by importing the track into Reaper, a digital audio workstation, and converting to the other formats. The resulting files all played flawlessly with foobar2000, so I believe they were not flawed files. Neither the WAV nor the FLAC at 24/192 would work properly over the OPPO optical link to the Onkyo preamp, EVER. Like Sonnie described it, sometimes it sputtered briefly and would not even give a few notes of the track, just a few spits and clicks. Other times it jerked along as a recognizable song but with gaps and sputters and always lots of digital distortion, it never sounded clean even intermittently at 24/192.

All other resolutions/bit rates sounded flawless via the optical - and all alike to our ears. But the test was brief, will be done more thoroughly in Feb. Hopefully we can get the optical line working at 24/192 by then, if possible.


----------



## ajinfla

Might be a hardware or even cable issue. 192k seems to stretch Toslink implementation limits. Even more reason to avoid such silly playback rates. 
For the scientific minded http://lavryengineering.com/pdfs/lavry-sampling-theory.pdf
And now back to our regular "amplifier sound" programming....


----------



## Savjac

We have also had some issues with 24/192 via to glass cable but it always seemed software related. I am not sure why the original FLAC was changed and maybe therein lies some of the issue. Has the FLAC file be used directly via the toslink to the Onkyo ? I know that is works fine on my Denon and the readout does say it is decoding 24/192 so if the Denon works I know that your processor will. 

There must be something happening in the conversion process that I do not understand.


----------



## Savjac

After listening to a good many 24/192 files I can say without a doubt that "Some" of these recordings at this bit rate do sound better than their lower bit rate counter parts. I do think that for most, including myself, 24/96 seems to be a very nice compromise as the difference between this and the higher rate is subtle to be sure. 
As to the usefulness of the digital connection, a brief note from Digital wiz Gordon Rankin may be of assistance.

_S/PDIF has no defined data rate and is therefore compatible with high-resolution digital music files up to 24-bit/192kHz. With S/PDIF the original word clock is extracted from the digital audio data packet via a PLL (Phase-Locked Loop receiver), which can be prone to digital timing errors such as jitter. However, there are a number of sophisticated and mature solutions that correct for jitter. Performance can be state-of-the-art. S/PDIF offers a connection that is reliable up to 20 meters in cable run length._




ajinfla said:


> Might be a hardware or even cable issue. 192k seems to stretch Toslink implementation limits. Even more reason to avoid such silly playback rates.
> For the scientific minded http://lavryengineering.com/pdfs/lavry-sampling-theory.pdf
> And now back to our regular "amplifier sound" programming....


----------



## Savjac

Sonnie said:


> I wonder if it could be the DAC in the Onkyo having issues with it, although it is supposed to be able to handle up to 192/32.


I am sure the Onkyo can handle anything you throw at it, it is a great unit.
One thing to keep in mind is that the DAC does not necessarily have a "Sound" to it but rather, the architecture surrounding the DAC is what will affect the final sound you hear. This is why some folks, myself included, tend to bypass the DAC in the AVR and use an external one which may be good, or may be bad because in essence we are tailoring the reproduction of the sound. Well I guess that is what we do anyway based on out purchase of equipment and speakers.


----------



## Sonnie

I told Wayne I suspected that optical cable. I can't imagine how they expect light to go through a clear tube. Don't they realize those higher bits are going to escape. :dontknow:


----------



## antoninus9

Architect7 said:


> Might have been the issue discussed in the link below combined with a clock that was off, maybe?
> 
> http://xiph.org/~xiphmont/demo/neil-young.html


Thank you for posting this link. A wonderfully detailed debunking of digital audio alchemy. The enthusiast community needs more of this valuable information.


----------



## ajinfla

Sonnie said:


> I told Wayne I suspected that optical cable.


One of you knuckleheads probably installed it backwards.
That's only for when you listen to Led Zeppelin!! :duh:


----------



## Sonnie

Yep... I suppose installing it backwards could cause excessive resistance to the signal since light is aiming backwards. Makes sense now.


----------



## Savjac

If we send the sound backwards at the speed of light, will we hear the music before they actually record it ?


----------



## antoninus9

Savjac said:


> If we send the sound backwards at the speed of light, will we hear the music before they actually record it ?


"The music is reversible but time isn't. Turn back...turn back..." Electric Light Orchestra, 'Face the Music' (backward mask)


----------



## AudiocRaver

Savjac said:


> We have also had some issues with 24/192 via to glass cable but it always seemed software related. I am not sure why the original FLAC was changed and maybe therein lies some of the issue. Has the FLAC file be used directly via the toslink to the Onkyo ? I know that is works fine on my Denon and the readout does say it is decoding 24/192 so if the Denon works I know that your processor will.
> 
> There must be something happening in the conversion process that I do not understand.


The original 24/192 FLAC would not play over the optical link. The short "test" snippet of the track was rendered in Reaper to a 24/192 WAV file. That would not play over the optical link, either. Both played fine in foobar2000 on my laptop where the rendering was done.


----------



## Savjac

Very odd indeed, I will have to think on this awhile. Thanks for posting this situation


----------



## antoninus9

I just ripped a test file from vinyl at 24/192 and it played back fine through TOSLINK. I hope this additional information is helpful.


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## Savjac

I also played a HD Tracks 24/192 file via toslink, a long cable at that, and it worked via my three 24/192 capable dacs using JRiver on a computer as a source.
I am not sure what has occurred in your case.
Let me try it off of a different computer to see if I obtain different results.


----------



## Bear123

I read through a large number of posts, and it would seem that there are three sides to this discussion.

1) Those who believe the answer is no, and cite factual data and testing to prove this is the case

2) Those who believe the answer is yes, but ignore the criteria for the test, such as cranking the volume into clipping, A/B switching without proper level matching, without eliminating visual bias etc.

3) Those who think they can hear the difference and are angry that proof suggest otherwise.

I am of the OPINION that the difference cannot be heard based on the information available, although I have never actually done a double blind test. Based on the opinion poll, it would appear that close to half of those responded claim they can hear the difference, although I would say it is most likely that most of those have ignored the criteria stated as far as level matched, within design paramaters, excluding visual bias etc etc., or overestimate their ability to hear differences that have been proven to be inaudible.


----------



## BeeMan458

When the curtain goes down and double-blind, ABX, protocols are applied, the best results, are random chance.

(gain matched, properly functioning, not driven into distortion...no clipping allowed, same speaker set, et cetera)

Everybody's hearing greatly improves when they know what they're looking at but let the light go out, and oddly, their hearing goes to sleep and the excuses come to light. What I find interesting, human's hearing, is at it's best when for survival purposes, they're depending on their hearing in the dark. Just saying, big cats can see in the dark, humans can't.

Love to read these types of debates, and for obviously good reasons, want no part in participating.

Does anybody have any double-blind ABX test links, put on by folks who can hear a difference?

An absence of proof, a fact does not make. There ain't no Yeti, Big Foot, Loch Ness Monster or T-Rexs hidden in the middle of Earth. And government does not look out for everybody's best interests. Yet there are those who know the above is false and now we have weekly shows of Aliens traveling through wormholes to come and serendipitously rediscover Earth, at least a half-dozen, if not more, times a day.


----------



## Bigun

Different amplifiers can have different measured performance and sound different. So what ?


----------



## littlejohn74

BeeMan458 said:


> An absence of proof, a fact does not make. There ain't no Yeti, Big Foot, Loch Ness Monster or T-Rexs hidden in the middle of Earth. And government does not look out for everybody's best interests. Yet there are those who know the above is false and now we have weekly shows of Aliens traveling through wormholes to come and serendipitously rediscover Earth, at least a half-dozen, if not more, times a day.


An interesting perspective, but lets not forget that it wasn't all that long ago, there wasn't any proof that the world is round, or that the earth orbits the sun, or the Higgs Boson particle exists.

Point being? We only know what we know and the lack of empirical data does not necessarily mean something doesn't exist or is untrue. This is especially the case when it comes to brain function.


----------



## BeeMan458

littlejohn74 said:


> Point being? We only know what we know and the lack of empirical data does not necessarily mean something doesn't exist or is untrue. This is especially the case when it comes to brain function.


When compared to most mammals, human hearing has repeatedly been shown to be very restricted in nature and testing equipment has time and again been proven to be far more sensitive than human hearing. Over and over and over and over, without failure, it has also been shown, when the curtain is up, differences are heard and when the same curtain goes down, hearing becomes no better than random chance or the act of guessing the flip of a coin.

In my book, that qualifies as far more empirical evidence than the entire universe coming into existence due to a single event we all know as, "The Big Bang Theory." And now we're dealing with infinite parallel universes.

The truth of the matter, this is all about money as cable guys sell multi-thousand dollar cables to guys with very expensive amplifiers. And in the process, folks make a bundle off selling amplifiers, musicians themselves can't afford to make music with. Despite all this inequality in recording vs playback equipment, these expensive amplifiers and cables, somehow make the playback of recorded music, better than the musicians themselves can make, when live.

...

(if consistently, over many tests, a group of twenty who claim a difference can be heard, are able to do better than random chance in ABX testing, I'll be happy to reconsider my position)


----------



## lcaillo

I don't know many audiophiles that believe that expensive cables and amps make music sound better than live performances. Of course, some recordings do sound better than a lousy venue with lots of crowd noise, but few would argue that for a given performance just using more expensive equipment to to reproduce the sound would be better than live. This is just hyperbole. There is much of that on both sides of the debate.

I also don't think most would argue that we don't have the ability to measure more precisely than human hearing. What they might argue is that we do not quantify what we hear with the measures we use today, and that would be correct. My opinion is that we could do a better job of measuring and using technology to describe what we hear.

There are, of course, many who claim to hear things that do not make any sense in any objective analysis. These experiences are no less real to those who report them than a measurement is to you or me. If people believe there is value in expensive cables or other products, it is no different than the value some see in expensive wine, jewelry, or automobiles.

I would say that it is not about money, but about meaningfulness. Those that sell what I would consider ridiculous products mostly do so because the believe their own story and because it resonates with some people. Those people find meaning in the experience of buying and owning those products, and if they experience something that you or I do not, who are we to judge.

Where I get off is where they try to sell their ideas to others who are looking for objective data and information based on reality, and when they dismiss those who don't buy their story and opt for information grounded in solid science.


----------



## BeeMan458

lcaillo said:


> IThis is just hyperbole.


Not at all.

If one were to look at the cables and parts used in stage produced sound and the same for recording studios, one will see what I suggest is anything but hyperbole.

As to it being about money, of course it is as that's how businesses stay in business and those who derived their income from business and who's fortunes are tied to how much surplus they can derive from the enterprise. The more charged over production/overhead costs, the better the owner's lifestyle.

And yes, it's none of my business what someone chooses to spend on their amplifiers and yes, like most, I'm happy to pay a premium for good looking gear.

(yesterday, we purchased the final touch for our living room based home theater, double recliner loveseat and matching rocker recliner, both with electric seats)

...:sn:


----------



## chashint

In the subjective ranks it appears to me the most noise is made by those at the entry level of separates and those folk argue both sides of the debate.
On the one hand their entry level amplifier blows their AVR (which in most cases just happens to now be their processor) out of the water and really wakes the speakers up.
On the other hand the people buying Brysten/McIntosh/Carver along with fancy wiring are wasting their money because there is only a possible 1% more improvement to be had over the entry level amp.

Debates about amps/wiring/audiophile gadgets used to bug me but now they amuse me.

If a real beginner is in an active thread and is beings bombed with audiophile pseudo science I try to provide links to what I consider valid information. Unfortunately the pseudo science usually sounds better and no knowledge is required about electrical theory to "understand " it.

There are a number of members here that freely a knowledge they own amplifiers simply because they want them.
I find that refreshing and I think that's more than enough reason to have one regardless of how much it cost or its perceived position in amplifier hierarchy.


----------



## tonyvdb

I could not agree more with that ^^


----------



## lcaillo

BeeMan458 said:


> Not at all.
> 
> If one were to look at the cables and parts used in stage produced sound and the same for recording studios, one will see what I suggest is anything but hyperbole.
> 
> As to it being about money, of course it is as that's how businesses stay in business and those who derived their income from business and who's fortunes are tied to how much surplus they can derive from the enterprise. The more charged over production/overhead costs, the better the owner's lifestyle.
> 
> And yes, it's none of my business what someone chooses to spend on their amplifiers and yes, like most, I'm happy to pay a premium for good looking gear.
> 
> (yesterday, we purchased the final touch for our living room based home theater, double recliner loveseat and matching rocker recliner, both with electric seats)
> 
> ...:sn:


What is hyperbole is your assertion that audiophiles believe "these expensive amplifiers and cables, somehow make the playback of recorded music, better than the musicians themselves can make, when live."


----------



## BeeMan458

This is what I posted: "Despite all this inequality in recording vs playback equipment, these expensive amplifiers and cables, somehow make the playback of recorded music, better than the musicians themselves can make, when live."

What I posted is my interpretation, of what I've read, that was written by others. On my part, there's no effort to exaggerate my interpretation of what I've read.


----------



## lcaillo

I disagree that most people who believe cables and amps make a big difference would say that they make any music sound better than what musicians can make live. I think this is a mischaracterization of most people's belief. Perhaps the audiophile fringe would say something like this, but I think it would be pretty far out on the fringe. I have known hundreds of people in the industry over the years who would argue that cables and amps make a big difference, but would never take the position you describe.

I think your interpretation is unfair and that this type of assumption does not help move the two sides of this debate closer to understanding the other's perspective.

That is my opionion, you don't have to agree.


----------



## Almadacr

chashint said:


> In the subjective ranks it appears to me the most noise is made by those at the entry level of separates and those folk argue both sides of the debate.
> On the one hand their entry level amplifier blows their AVR (which in most cases just happens to now be their processor) out of the water and really wakes the speakers up.
> On the other hand the people buying Brysten/McIntosh/Carver along with fancy wiring are wasting their money because there is only a possible 1% more improvement to be had over the entry level amp.
> 
> Debates about amps/wiring/audiophile gadgets used to bug me but now they amuse me.
> 
> If a real beginner is in an active thread and is beings bombed with audiophile pseudo science I try to provide links to what I consider valid information. Unfortunately the pseudo science usually sounds better and no knowledge is required about electrical theory to "understand " it.
> 
> There are a number of members here that freely a knowledge they own amplifiers simply because they want them.
> I find that refreshing and I think that's more than enough reason to have one regardless of how much it cost or its perceived position in amplifier hierarchy.


Well there's some reason to that ! Do you believe that someone that spent 50K in a 2 channel system going to admit that he could do a great system for 1/10 of that number ? Every year i go to the audio show here in Montreal and it's ..... choosing the best word .. a circus . I can tell you that Audioquest takes a bigger room than Focal just to give you a idea .


----------



## littlejohn74

BeeMan458 said:


> When compared to most mammals, human hearing has repeatedly been shown to be very restricted in nature and testing equipment has time and again been proven to be far more sensitive than human hearing. Over and over and over and over, without failure, it has also been shown, when the curtain is up, differences are heard and when the same curtain goes down, hearing becomes no better than random chance or the act of guessing the flip of a coin......................
> 
> ...............
> The truth of the matter, this is all about money as cable guys sell multi-thousand dollar cables to guys with very expensive amplifiers. And in the process, folks make a bundle off selling amplifiers, musicians themselves can't afford to make music with. Despite all this inequality in recording vs playback equipment, these expensive amplifiers and cables, somehow make the playback of recorded music, better than the musicians themselves can make, when live.
> 
> ...
> 
> (if consistently, over many tests, a group of twenty who claim a difference can be heard, are able to do better than random chance in ABX testing, I'll be happy to reconsider my position)


All the equipment and testing you speak of merely describes what the human ear is capable of hearing. The picture that all these numbers are unable to paint is how the sound is processed in the brain of each individual.

The analogy I use, would be our understanding of human taste. By removing the sense of smell, familiar foods can taste completely different.
(If you get a chance, try tasting some vanilla seeds with your nose blocked and then without)
Similarly, what one man "sees" isn't necessarily the same as what the next man "sees". Sure, a chair is a chair. But one man might see a green chair, whilst the next man would see a "greenish" chair. Even though when measured, the light wavelength is the same.


I'm not proposing that all expensive amps sound better than entry level amps or vice versa, but I am of the opinion that different amps can and will sound different.


----------



## lcaillo

My guess is that you overestimate the differences in amps, and underestimate the differences in experience due to a myriad of other factors. Yes, sometimes amps sound different, but where there is not significant measurable distortion, or some non-linearity, or inadequate power, I believe most people would not be able to tell a difference in blind testing of most amps. 

As you point out, there is much to what we hear that is in the mind.


----------



## chashint

Almadacr said:


> Well there's some reason to that ! Do you believe that someone that spent 50K in a 2 channel system going to admit that he could do a great system for 1/10 of that number ? Every year i go to the audio show here in Montreal and it's ..... choosing the best word .. a circus . I can tell you that Audioquest takes a bigger room than Focal just to give you a idea .


Just like some of the people who spent money on their Emotiva will not admit it sounds the same as the AVR ???


----------



## Bear123

We have a lot of members with amazingly acute hearing. Fully half of them, based on the survey, can hear what cannot be measured by equipment supposedly far more sensitive than human hearing. :scratch:


----------



## Mike0206

Bear123 said:


> We have a lot of members with amazingly acute hearing. Fully half of them, based on the survey, can hear what cannot be measured by equipment supposedly far more sensitive than human hearing. :scratch:


 That's a great observation. Lol! The only thing I can hear below 20hz is clipping and popping. Lol!


----------



## lcaillo

These users believe that they can hear a difference in amps. I would disagree about whether than can hear something we cannot measure. They may perceive something that is not really there, so not measureable at all, due to expectation bias or other reasons, or they may hear something that we have not learned how to identify. I believe we can measure much that we do not currently report in amplifier and other specifications.


----------



## littlejohn74

lcaillo said:


> These users believe that they can hear a difference in amps. I would disagree about whether than can hear something we cannot measure. They may perceive something that is not really there, so not measureable at all, due to expectation bias or other reasons, or they may hear something that we have not learned how to identify. I believe we can measure much that we do not currently report in amplifier and other specifications.


Or do you think it is feasible that there hasn't been enough research and therefor understanding into how each measurement or combination of measurements actually affects the final output. Perhaps there is is even a specification which is overlooked but has an affect on performance.

I wonder if the folks that believe that "if the specifications are the same, then it must sound the same" feel the same way about speakers, particularly subwoofers.
Over in the subwoofer forums, it is generally accepted that "numbers don't paint the full picture"

The other interesting theme that keeps popping up in these discussions, is the assumption that folks who believe there is an audible difference are spending lots of money on amplifiers and therefore need to justify the expense.
I thought the question was "Can we really hear the difference between amps?" not Do expensive amps sound better?
I am of the belief that there is an audible difference between amp designs, whether or not there is a direct relationship between the cost of an amp and the sound quality is debatable.

Disclaimer: I used to think, to get a top performing amp, I needed to spend top dollar. I recent times, I have shifted towards pro audio amps, which imo perform as well if not better than"audiophile" amp for a fraction of the cost.
But even within these ranks, I believe there is an audible difference between amps. More often than not, if the amp design is basically the same then it can be difficult to hear a difference if at all, but between different amp designs.....


----------



## lcaillo

littlejohn74 said:


> Or do you think it is feasible that there hasn't been enough research and therefor understanding into how each measurement or combination of measurements actually affects the final output. Perhaps there is is even a specification which is overlooked but has an affect on performance.


I believe that there has not been enough research to try to identify and quantify what it is that people are hearing when they identify differences. Certainly many of those differences are due to belief. I believe some of them are likely real differences, but subtle. 



littlejohn74 said:


> I wonder if the folks that believe that "if the specifications are the same, then it must sound the same" feel the same way about speakers, particularly subwoofers.
> Over in the subwoofer forums, it is generally accepted that "numbers don't paint the full picture"


It is clear that the majority do not feel the same way about speakers here at HTS. I think numbers mostly do paint a good picture with subwoofers, but the numbers are hard to sort out sometimes because of room effects.



littlejohn74 said:


> The other interesting theme that keeps popping up in these discussions, is the assumption that folks who believe there is an audible difference are spending lots on money on amplifiers and therefore need to justify the expense. I thought the question was "Can we really hear the difference between amps?" not Do expensive amps sound better?


I don't see that as an assumption in most of the discussions I see here. I think people use expensive amps and cables as examples but many discussions here also go into whether there are differences in modestly priced products like AVRs and pro gear.


----------



## Almadacr

chashint said:


> Just like some of the people who spent money on their Emotiva will not admit it sounds the same as the AVR ???


AVR's for me they all sound different since they all have different DAC's inside but if you ad a amp will change the sound .... nope . 

Sometimes i have the impression if someone is confusing headroom with sound !


----------



## BeeMan458

Can you hear the difference between a new violin and a Stradivarius?

Ten world-class soloists put costly Stradivarius violins and new, cheaper ones to a blind scientific test. The results may seem off-key to musicians and collectors, but the new instruments won handily.

When the lights were dimmed and the musicians donned dark glasses, the soloists' top choice out of a dozen old and new violins tested was by far a new one. So was the second choice, according to a study published Monday in the Proceedings of the National Academy of Sciences.

---snip---

But when the lights were turned down, all that could be judged was the sound. Some violins were 300 years old. Some were days old.

And when the soloists were asked to guess whether the violins they were playing were old or new, the soloists got it wrong 33 times and right 31 times.

.............................................

And like amplifiers, when the curtain goes down, no better than chance.

...


----------



## chashint

This is interesting, my wife happens to play violin and when she has spoken about them and what separates the quality levels it has not been in the context of how they sound.
It is in the context of how they feel in her hands and how easy they are to play.
Being of humble means she has never held much less played a $30k+ instrument so there may be a point of diminishing returns on feel as well as sound quality.
I am kinda surprised that the collection of musicians involved at least a couple of them did not recognize some of the old instruments by touch.

Nice find on the article.


----------



## BeeMan458

chashint said:


> Nice find on the article.


Thanks!

I found it interesting as when the curtain goes down, like with amplifiers, those making the choices, did no better than random chance.

I would have never guessed, in a million years, that experience violinists would not be able to tell the difference in the many differing violins. That total floored me as not even remotely possible.

Do you dare put a $30K violin in your wife's hands?

...


----------



## 3dbinCanada

BeeMan458 said:


> Thanks!
> 
> I found it interesting as when the curtain goes down, like with amplifiers, those making the choices, did no better than random chance.
> 
> I would have never guessed, in a million years, that experience violinists would not be able to tell the difference in the many differing violins. That total floored me as not even remotely possible.
> 
> Do you dare put a $30K violin in your wife's hands?
> 
> ...


I keep reiterating this point....if you place compare amps and or AVRs and play them with identical loads in the same acoustic environment using the same source and driving them well within the design limits of the weaker unit, then you will not be able to reliably determine the difference between the units.


----------



## chashint

BeeMan458 said:


> Do you dare put a $30K violin in your wife's hands?
> 
> ...


Let's not go there ;-))


----------



## BeeMan458

chashint said:


> Let's not go there ;-))


...LOL....

Maybe a really nice bow, of her choice, for an anniversary present? If lucky, you'll get by for under $5k.

...


----------



## gdstupak

*The violin challenge:*
It doesn't surprise me that modern well made violins can compete with older well made violins. Instrument making isn't a lost art form.
A well made Stradivarius is expensive because it is good, but a higher premium price is placed on them simply because of name and prestige. A modern well made violin can play just as well but won't be as expensive simply because it doesn't have that mystique. 

Also, it doesn't surprise me that the old and new violins could not be differentiated. There isn't a feeling for 'old.' There is a feeling for 'different.'


*AVR's/DAC's:*
Almadacr makes a good point that AVR's can sound different because of DAC's. DAC's definitely can affect sound.


----------



## tonyvdb

gdstupak said:


> *AVR's/DAC's:*
> Almadacr makes a good point that AVR's can sound different because of DAC's. DAC's definitely can affect sound.


Im not in agreement, the discussion going here seems to indicate otherwise.
If implemented correctly (and most are) there should be no audible difference. Processing such as auto room EQ will have a much more noticeable effect but that is not within the scope of this discussion nor are DACs


----------



## gdstupak

EDIT: I'm erasing the post that was here because it had faulty information from a faulty memory.
I'm in agreement with Tony.


----------



## lcaillo

Anyone want to contribute to a fund to purchase a very high resolution digital capture system and a copy of Matlab. If so I will be happy to compare the output of any devices and the input and output of any devices. I think if we can sample at about 1 Mhz at 24 bits and have the signal processing and statistical capability to apply to the data, we should be able to determine if there are differences between signals. The amps can be compared driving actual music into actual speakers as well as comparing input and output and deriving the transfer functions, much like Carver claimed to do years ago, but with far higher precision.

If we are really interested in learning something, let's approach this systematically using state of the art technology.


----------



## BeeMan458

There's DSP and there's DAC. All a DAC does is seamlessly convert digital to analogue where as a DSP is intended to alter sound quality; Digital Sound Processor.

As to AVR, AVR is used in the sense of the amplifier in the AVR.

Anybody who wants is welcome to chime in and explain to me what ever it is I'm missing or not understanding.

......................................................

What kind of cost are you posting about regarding MATLAB and a "high resolution digital capture system?"


----------



## gdstupak

Tony,
I apologize for my earlier statement regarding DAC's. My computer sound card has customizeable opamps which altered the sound. I have had no experience of DAC's affecting sound characteristics.


----------



## tonyvdb

Oh, no problem at all


----------



## Savjac

BeeMan458 said:


> Can you hear the difference between a new violin and a Stradivarius?
> 
> Ten world-class soloists put costly Stradivarius violins and new, cheaper ones to a blind scientific test. The results may seem off-key to musicians and collectors, but the new instruments won handily.
> 
> When the lights were dimmed and the musicians donned dark glasses, the soloists' top choice out of a dozen old and new violins tested was by far a new one. So was the second choice, according to a study published Monday in the Proceedings of the National Academy of Sciences.
> 
> ---snip---
> 
> But when the lights were turned down, all that could be judged was the sound. Some violins were 300 years old. Some were days old.
> 
> And when the soloists were asked to guess whether the violins they were playing were old or new, the soloists got it wrong 33 times and right 31 times.
> 
> .............................................
> 
> And like amplifiers, when the curtain goes down, no better than chance.
> 
> ...


It would appear, though I may be misguided, that you feel this article, one article, negates the personal belief of hundreds of thousands of individuals over many years ? This seems a bit convenient don't you think ? Why would world class performers of all ages, areas of expertise back grounds and beliefs spend money on better equipment if it all sounds the same ? I am baffled by this train of thought as it supports nothing but the writer of the article. How is it possible that so many brands and types of musical instruments and electronics be available and yet none have anything better to offer than any other piece. Why do we read millions of lines of dialogue discussing the profound beliefs by humans that brand X sounds or performs better than brand Y ? 

Being skeptical is a good thing, being irrational is not, and to be intimating that many of us are doing nothing more than fooling ourselves into thinking one product may sound or perform better, in our opinions that a similar product is sheer unmitigated hubris on the part of the writer of that article or in some ways those that put that contest together. In the end one performer sums the whole experiment up with the words thought in that he would rather play a newer violin that sounds and performs better than an older one that may sound and perform inferior. That makes a good bit of sense to me. I also do not find any substantial comments by the performers, only listeners making grades. Although if it is true, I can now feel much better that my guitar collection is not all high end stuff as there is really no difference between brands. :dontknow:


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## 3dbinCanada

Savjac said:


> It would appear, though I may be misguided, that you feel this article, one article, negates the personal belief of hundreds of thousands of individuals over many years ? This seems a bit convenient don't you think ? Why would world class performers of all ages, areas of expertise back grounds and beliefs spend money on better equipment if it all sounds the same ? I am baffled by this train of thought as it supports nothing but the writer of the article. How is it possible that so many brands and types of musical instruments and electronics be available and yet none have anything better to offer than any other piece. Why do we read millions of lines of dialogue discussing the profound beliefs by humans that brand X sounds or performs better than brand Y ?
> 
> Being skeptical is a good thing, being irrational is not, and to be intimating that many of us are doing nothing more than fooling ourselves into thinking one product may sound or perform better, in our opinions that a similar product is sheer unmitigated hubris on the part of the writer of that article or in some ways those that put that contest together. In the end one performer sums the whole experiment up with the words thought in that he would rather play a newer violin that sounds and performs better than an older one that may sound and perform inferior. That makes a good bit of sense to me. I also do not find any substantial comments by the performers, only listeners making grades. Although if it is true, I can now feel much better that my guitar collection is not all high end stuff as there is really no difference between brands. :dontknow:


What this article shows is sight bias definately plays into the role of what one hears. Do deny this one fact is to deny that audiophiles and golden ears are human, trained or not. I've seen this article posted in other forums and I see the same kind of reaction coming from the audiophiles in totally dismissing the articles merit.


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## BeeMan458

"Why would world class performers of all ages, areas of expertise back grounds and beliefs spend money on better equipment if it all sounds the same ?"

Same reason one would spend tens of millions to hang a Picasso on their wall, ego.

The comments are based on double-blind ABX tests and when the curtain is up, the experts are right up there with making the right choice.....a hundred percent of the time but once the curtains go down, these same experts, with the same gear and setup are reduced in their expertise to no better than <50% or random chance.

Agreed, this is a hard egg to wrap one's think around.


----------



## mb350

I always thought you could hear a difference but got a big surprise recently. I had some old class A/B amps - a Sansui integrated amp, a Carver TFM15 and TFM45, and a hand built Leach amp that used Motorola transistors. In listening the Sansui was definitely harsher than the Carvers, and the Carvers sounded very warm. But when placed against the Leach amp that warmth was really distortion and the Leach amp was far better, great clarity without the harshness.

Then last year I bought a Yamaha RX-A830 HT receiver and fully expected to use the pre-outs to go to the "superior" Leach amps. Well, surprise, surprise, I couldn't tell the difference between the Leach amps and those inside the Yamaha. That receiver is not esoteric at all, and I can only conclude that amplifiers are built much better now and it is a truism that there are no sonic differences detectable by the human ear between amplifiers (leaving aside the question of differences that may arise from differing topologies - class a vs a/b vs d).


----------



## Savjac

BeeMan458 said:


> "Why would world class performers of all ages, areas of expertise back grounds and beliefs spend money on better equipment if it all sounds the same ?" Same reason one would spend tens of millions to hang a Picasso on their wall, ego. The comments are based on double-blind ABX tests and when the curtain is up, the experts are right up there with making the right choice.....a hundred percent of the time but once the curtains go down, these same experts, with the same gear and setup are reduced in their expertise to no better than <50% or random chance. Agreed, this is a hard egg to wrap one's think around.


Maybe we did not watch the same video, I saw no experts giving an opinion. The opinions were provided by folks not playing. It would seem to me that this test was designed by the new manufacturers trying to improve sales or something. The violins were on the table for all to see and the glasses did not prevent any player from picking what they wanted. Further I cannot for the life of me believe anyone that owns a multi million dollar strad would allow their instrument to be bounced around in the dark awaiting sure damages. Also please note that so many variables were thrown into the mix such as different halls, pianos, entire ensembles all changing the parameters of the game. Again though the most telling aspect of this stupid excersize is that no one interviewed the performers, they really only tallied information gathered from the audience. So if the headline reads, performers can't tell the difference maybe we should hear from them. 

Abx does not work, it never has for much of anything in life. Imagine picking a spouse utilizing an abx double blind test, yeah same results.


----------



## BeeMan458

Savjac said:


> Maybe we did not watch the same video, I saw no experts giving an opinion.


I posted links to articles, not videos and the names of the experts and soloists (Ex: Ilya Kaler) were included in the article.

...






Here's the same link which shows it was a university quality study.

The article/findings were published in a peer reviewed magazine.

"Proceedings of the National Academy of Sciences"

"Player preferences among new and old violins"

I'm not the one who should be questioned. This is not a one off article with no merit. My recommendation would be to contact the authors and university personnel regarding your concerns with this issue. I will stop responding as you're not wanting to accept findings by learned persons on this matter. I'm not a scholar. Maybe you have studies you can link to that conflict with this study. I'm dependent on the findings of others who are scholarly. I'm happy to let those who are more knowledgeable on matters of this kind, challenge the findings of those who are more scholarly on these matters, than I.


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## willis7469

I just read the "players preference" article/study. (It's all I have time for at the moment). One thing I found clear was that there was a distinct preference for the new violins. While the ability to discern old vs new was seemingly to chance, the consistent preference for the new violins spoke to me as a player of instruments. It seems that 200 years worth of refinements have made it possible to build an instrument whose sensitivity and feedback made it more rewarding to play. The same way I feel a different connection to a particular "Taylor" guitar vs a lesser refined, and crafted J. Turser. Both rewarding, but in different ways. Yes I know comparing a 2k guitar to a muti million dollar strad constitutes it's own discussion, but the point is, if there were "listener" preferences to coincide with player feedback this would have been more relevant. (To me anyway) Especially in the sense that connecting to an instrument while playing it is vastly different than listening to someone else playing one, which is what I found showcased here. Blind chance for amps, well...
For the record, I'm only sharing my observation of one of the posted articles, which IMO made more of a case for distinct preference. 
I'll be happy to check your other links later Bee!
Ciao!


----------



## BeeMan458

willis7469 said:


> For the record, I'm only sharing my observation of one of the posted articles, which IMO made more of a case for distinct preference.


"And when the soloists were asked to guess whether the violins they were playing were old or new, the soloists got it wrong 33 times and right 31 times."

The title of the article is: "You can't hear the difference between a Stradivarius and new violins"

I was discussing the ability of folks to choose one over the other and how even when a vaunted instrument such as a Stradivarius, with it's "signature sound," experienced violinists whiff the ball when asked to make a choice. It's the same for double-blind ABX tests using amplifiers. All the golden ears in the world have failed to choose above random chance in properly conducted double-blind ABX tests, yet folks persist in saying there's a distinguishable difference that only shows when the test is sighted.

My comments and links were to support the validity of my comments to one who denigrated the validity of the article as opposed to an effort on my part at creating more controversy surrounding personal preference as that was not the point of the article or links to further followup on the matter.

I've posted enough quality links on this matter so it will best serve the thread for me to step out of the discussion.

(please let me step outside the thread as opposed to trying to bring me back in again with inflammatory comments)


----------



## willis7469

Hey Bee I hope you don't think I'm trying to drag you anywhere. I just wanted to share my observation of this article:
http://www.pnas.org/content/109/3/760.full?sid=da8ca8bf-7525-473f-8420-a2df481445c7
It was titled players preferences for violins(sorry the paraphrase, I can't see the title on this page) not that they can't tell the difference between a strad, and a new one. Maybe were talking about the same link?
No inflammation. (Intended) Sorry.


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## willis7469

Bye, if I wanted inflammation, I'd go collect some field stone and build my wife another flower bed! Lol


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## BeeMan458

willis7469 said:


> Hey Bee I hope you don't think I'm trying to drag you anywhere.


I don't think you're trying to drag/take me anywhere. One article was based on the other. If there was confusion, it was my doing. As to inflammatory, no apology necessary as you didn't say anything inflammatory about the article. My comment applied to another. I figure I've posted enough on the matter and rather than get circular, in my opinion, I've posted enough on the matter and figure it best for me to step out of the conversation as again in my opinion, folks can think, say and do anything of their choosing that hasn't been legislated against and even then, the courts are full of people who didn't get the memo.

In our case, our system is set up and dialed in; verified by REW. When watching a movie, a house curve is applied and at the end of the movie, the house curve is removed. Whether there's a difference between amplifiers, in my opinion is not consequential. In my opinion, one should dial their gear in, apply any house curve to their satisfaction and enjoy viewing movies as in the end, that's what it's all about.

As to differences in sound, multiple poorly EQ'd systems, various speaker placement, changing conditions, double-blind vs sighted tests, et cetera are sufficient cause for differences. On my part, my apologies for miscommunicating my thoughts on the matter and making you self-conscious as you posted nothing I should take offense for, nor that you should apologize for.

(i do try and so fail.........sigh)

...


----------



## NBPk402

BeeMan458 said:


> I don't think you're trying to drag/take me anywhere. As to inflammatory, no apology necessary as you didn't say anything inflammatory about the article. My comment applied to another. I figure I've posted enough on the matter and rather than get circular, in my opinion, I've posted enough on the matter and figure it best for me to step out of the conversation as again in my opinion, folks can think, say and do anything of their choosing that hasn't been legislated against and even then, the courts are full of people who didn't get the memo.
> 
> In our case, our system is set up and dialed in; verified by REW. When watching a movie, a house curve is applied and at the end of the movie, the house curve is removed. Whether there's a difference between amplifiers, in my opinion is not consequential. In my opinion, one should dial their gear in, apply any house curve to their satisfaction and enjoy viewing movies as in the end, that's what it's all about.
> 
> On my part, my apologies for miscommunicating my thoughts on the matter and making you self-conscious as you posted nothing I should take offense for.
> 
> (i do try and so fail.........sigh)
> 
> ...


Why do you remove the house curve after watching a movie... Is it because it doesn't sound as good for listening to music (I have never listened with any curve, hence the question)?:T


----------



## BeeMan458

ellisr63 said:


> Why do you remove the house curve after watching a movie... Is it because it doesn't sound as good for listening to music (I have never listened with any curve, hence the question)?:T


We don't listen to music. We listen to the television and we watch movies.

My wife's hearing is to sensitive for full on reference level listening. So, I dialed the system in, found a level that was acceptable to my wife, which robbed the center channel and the LFE channel. So I created a house curve that would satisfy the wife's hearing and increase the LFE and CC according to allow for almost reference level bass and dialogue.

I set the MVC to -17.5dB and the LFE channel is jacked +10dB and the CC is jacked +7dB. All other channels (surrounds and mains) are left the same. I find we don't need reference level bass while the wife is watching "Real Housewives" or while we're watching Giants' baseball.

So it's house curve in for movies and house curve out for regular programming.


----------



## NBPk402

BeeMan458 said:


> We don't listen to music. We listen to the television and we watch movies.
> 
> My wife's hearing is to sensitive for full on reference level listening. So, I dialed the system in, found a level that was acceptable to my wife, which robbed the center channel and the LFE channel. So I created a house curve that would satisfy the wife's hearing and increase the LFE and CC according to allow for almost reference level bass and dialogue.
> 
> I set the MVC to -17.5dB and the LFE channel is jacked +10dB and the CC is jacked +7dB. All other channels (surrounds and mains) are left the same. I find we don't need reference level bass while the wife is watching "Real Housewives" or while we're watching Giants' baseball.
> 
> So it's house curve in for movies and house curve out for regular programming.


:T :T


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## Savjac

Interesting Bee,

We do agree on something you know, I never really listen at reference level, it is not comfortable for me or Lady Jac.

I do not change settings between music and movies but I do see why you would find it necessary based on your viewing choices.
I really do not want anyone to think they are being pushed or guided or mis guided for that matter based upon my thoughts and ideas. I do expect that those in a discussion will consider my thoughts and ideas and look into the matter, research and come back with additional thoughts, that is what conversation is. Imagine if we took everything that the fools on the hill say as truthful and honest without doing any research on what they say. I think lemmings is the word they use, so an honest and open dialogue is a good thing to enter into and this is a good site for that because we cannot, or will not enter into name calling or anything of that nature, most of us are way to old for that. We may touch a nerve now and then when a firm belief is questioned by an outside radical that speaks to something other than conventional thought. 
In the case of the musicians and the violins, I did read the text and I actually watched the video of the actual performances and testing. To me it was clear that the musicians really did not matter in the testing and their opinions do not appear to be sought, only the musings and grading turned in by audience members. Even one of the panel gets all giddy because he now has gobs of data to translate and present, not necessarily correct date as we all know, data can be skewed. Kind of like the unemployment figures we see every month, the ones were people no longer collecting unemployment are dropped from the lists.

I shall not get too deep into the challenge linked to, but let me say, I deal in the investigation, collection and presentation of empirical evidence and have been on top of that for some 34 years. I can usually see a set up when I read it. None the less, I shall say no more about it, as the great Einstein once said when speaking about ABX testing, doing the same thing over and over again and expecting different results is the definition of insanity. :rofl:


----------



## littlejohn74

Savjac said:


> Interesting Bee,
> 
> We do agree on something you know, I never really listen at reference level, it is not comfortable for me or Lady Jac.
> 
> I do not change settings between music and movies but I do see why you would find it necessary based on your viewing choices.
> I really do not want anyone to think they are being pushed or guided or mis guided for that matter based upon my thoughts and ideas. I do expect that those in a discussion will consider my thoughts and ideas and look into the matter, research and come back with additional thoughts, that is what conversation is. Imagine if we took everything that the fools on the hill say as truthful and honest without doing any research on what they say. I think lemmings is the word they use, so an honest and open dialogue is a good thing to enter into and this is a good site for that because we cannot, or will not enter into name calling or anything of that nature, most of us are way to old for that. We may touch a nerve now and then when a firm belief is questioned by an outside radical that speaks to something other than conventional thought.
> In the case of the musicians and the violins, I did read the text and I actually watched the video of the actual performances and testing. To me it was clear that the musicians really did not matter in the testing and their opinions do not appear to be sought, only the musings and grading turned in by audience members. Even one of the panel gets all giddy because he now has gobs of data to translate and present, not necessarily correct date as we all know, data can be skewed. Kind of like the unemployment figures we see every month, the ones were people no longer collecting unemployment are dropped from the lists.
> 
> I shall not get too deep into the challenge linked to, but let me say, I deal in the investigation, collection and presentation of empirical evidence and have been on top of that for some 34 years. I can usually see a set up when I read it. None the less, I shall say no more about it, as the great Einstein once said when speaking about ABX testing, doing the same thing over and over again and expecting different results is the definition of insanity. :rofl:


+1.

I think it is fair to say that anyone who has studied statistics and performed their own Study/Trials understands that no matter how empirical or unbiased the results of a study appears, the findings are always susceptible to the bias of those who are conducting the study.


----------



## BeeMan458

Savjac said:


> I shall not get too deep into the challenge linked to, but let me say, I deal in the investigation, collection and presentation of empirical evidence and have been on top of that for some 34 years.


Hopefully you found my layperson's efforts at supporting my comments refreshing as opposed to tedious. I have retired from my expertise so the most I may lay claim to today, is being that of an incompetent old fool living a life of leisure. I enjoy this title as I'm responsible for nothing. It's been my life's goal and I'm enjoying the benefit of having achieved this goal.

...

.......................................................................

I'm sure at the appropriate time we could have an excellent discussion about unemployment numbers, the number of real jobs created over the current administration's claims vs an ever increasing population vs U6.


----------



## Savjac

BeeMan458 said:


> Hopefully you found my layperson's efforts at supporting my comments refreshing as opposed to tedious. I have retired from my expertise so the most I may lay claim to today, is being that of an incompetent old fool living a life of leisure. I enjoy this title as I'm responsible for nothing. It's been my life's goal and I'm enjoying the benefit of having achieved this goal. ... ....................................................................... I'm sure at the appropriate time we could have an excellent discussion about unemployment numbers, the number of real jobs created over the current administration's claims vs an ever increasing population vs U6.


Indeed sir I did enjoy our discussion. I pray that one day I may retire as well however the dreams of my youth have turned into less than satisfactory realities of today. 
Oh well, best laid plans.
I would love to enter a discussion re unemployment as that particular subject has hit my wife and I hard and I do not have sufficient knowledge of claims being made vs truth. I just as a matter of course do not believe anything they say that contradicts my travels and observations. 
Bring it on, in another thread.


----------



## BeeMan458

Savjac said:


> I would love to enter a discussion re unemployment as that particular subject has hit my wife and I hard and I do not have sufficient knowledge of claims being made vs truth. I just as a matter of course do not believe anything they say that contradicts my travels and observations.
> Bring it on, in another thread.


My sympathies as I do not envy anybody in your position. PM me anytime you're up to conversation.


----------



## ajinfla

Savjac said:


> Abx does not work


Actually it does, as do many other forms of controlled tests.



Savjac said:


> Imagine picking a spouse utilizing an abx double blind test, yeah same results.


Classic Red Herring. No one claims that all non-pathological spouses all sound no different.

Attacking the de facto standard of science, including perceptual science, for the sake of it puts one in an awkward position Jack. Especially for a classical music lover like yourself.
Doubt you would be aware of this given your stated position as an audiophile, but here _is_ how women are selected....*blind* http://www.theguardian.com/women-in-leadership/2013/oct/14/blind-auditions-orchestras-gender-bias 

cheers


----------



## lcaillo

Just because a test is of a particular format does not make it valid. There are many ways that a double blind test could be manipulated or ineffective, either by intent or not. That said, they do serve a purpose and I believe that even given the ability to listen until they claim they could easily tell a difference, many would fail in blind testing to identify differences.


----------



## Savjac

ajinfla said:


> Actually it does, as do many other forms of controlled tests.
> 
> 
> Classic Red Herring. No one claims that all non-pathological spouses all sound no different.
> 
> Attacking the de facto standard of science, including perceptual science, for the sake of it puts one in an awkward position Jack. Especially for a classical music lover like yourself.
> Doubt you would be aware of this given your stated position as an audiophile, but here _is_ how women are selected....*blind* http://www.theguardian.com/women-in-leadership/2013/oct/14/blind-auditions-orchestras-gender-bias
> 
> cheers


Aj you little joker you :clap:

I agree there is a bias in all of business inclusive of music. I used to be involved with a large classical ensemble in Chicago and I saw this first hand, I do wish they would have used blind listening for the hiring process. Maybe not just for women either. :whistling:


----------



## BeeMan458

Just saying, for what she brings to the process, my favorite female violin performer:


----------



## Savjac

lcaillo said:


> Just because a test is of a particular format does not make it valid. There are many ways that a double blind test could be manipulated or ineffective, either by intent or not. That said, they do serve a purpose and I believe that even given the ability to listen until they claim they could easily tell a difference, many would fail in blind testing to identify differences.


I am wondering how much would change if the parameters changed ? Yes, manipulation either intended or not will cause a bias but not necessarily on the participant. Having said that though, I still think that AB or Blind tests as done thus far have run their course and they really, in my mind, do not present a real world set of parameters. I think it was you Leonard that said something to the effect that with time you may hear things you did not hear initially and even though said things were present at the start, you either learned to listen for these things or changing gear made these things more apparent. Once heard never forgotten ?

When one spends real time with something, one can easily learn to allow that something to settle in if you will and once something else has been swapped in, a difference may be heard. However, if we listen for a time to the new item, say a week or so, and then go back to the original item, any changes that may have been missed become very apparent. I can guarantee AJ would know his products blind listening or not, from other items not of his design. I have never designed anything so good so I cannot make that claim. 

Time and familiarity seem to be a key here, Maybe ??


----------



## NBPk402

Do you remember when Bob Carver had that challenge and he took his SS amp and made it sound like a tube amp?


----------



## Savjac

ellisr63 said:


> Do you remember when Bob Carver had that challenge and he took his SS amp and made it sound like a tube amp?


Yes Ron I remember very well. 
I was actually quite amazed at the time, but not so much any more as I do believe that changes in circuits and components can change the sound of electronics.


----------



## chashint

ellisr63 said:


> Do you remember when Bob Carver had that challenge and he took his SS amp and made it sound like a tube amp?


That SS amp was modified in such a way that it would be considered defective, in regards to distortion and frequency response.
Distortion and frequency roll off is generally considered bad, but the countless devoted warm tube sound lovers would not necessarily agree.


----------



## BeeMan458

Savjac said:


> However, if we listen for a time to the new item, say a week or so, and then go back to the original item, any changes that may have been missed become very apparent.


Tests have been run on this point where the participants own amplifier was used along with familiar material the participant was intimate with. And the results were, when the participant compare their gear and content to a run of the mill mooch AVR amplifier, once the curtain was pulled down, the correct choice ratio became that of random chance.

When the curtain was up (sighted) there was no problem differentiating one's gear from another piece of gear and when the curtain was down, the opposite. Oh, and I might add, when the curtain was up, there were no excuses as to the why of the participants success. It was understood the reason for their success was because differences were so apparently obvious. But when the curtain was down, the same setup, in ABX testing, the "excuses" started rolling in that somehow everything was no longer fair because magically, everything became unfair when the curtain was pulled down.

Myself, I went into this whole difference thing, convinced there were differences to be heard and did my level headed best to maintain this point. One day, I asked myself the esoteric question, how do I really listen to music? Do I listen all curled up in the fetal position, straining while in critical listening mode or do I listen with distractions surrounding me; friends, family, food, wine and additional distracting entertainment? At the point of giving an honest answer, I let go and have never looked back.

In my opinion, ABX tests have shown, the difference is in the mind and one is best served wearing blinders over their eyes, so they can't see the physical world.

Our system? It's reached a quality level where in honesty, my wife says she can't hear differences because it all sounds good. So as to not drive her crazy, I no longer ask her opinion but at the same time, she makes a point, at what point is good, good enough?


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## chashint

It's good enough when you run out of money or lose interest in messing with it anymore .... either one may occur first and neither may be a permanent condition.


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## BeeMan458

chashint said:


> It's good enough when you run out of money or lose interest in messing with it anymore .... either one may occur first and neither may be a permanent condition.


I should rephrase the comment as the question is rhetorical in nature. The comment has to do with having the ability to recognize that good enough, has been reached.

(my fault for not recognizing and correcting my comment to reflect this point)


----------



## NBPk402

chashint said:


> That SS amp was modified in such a way that it would be considered defective, in regards to distortion and frequency response.
> Distortion and frequency roll off is generally considered bad, but the countless devoted warm tube sound lovers would not necessarily agree.


Yes, but my point was that the amp did sound different. Do you think you could pick out the tube amp from a SS amp in a blind test? I think you might be able too... Depending on the amps in question. Do I think you can pick out an amp between 2 ss amps... Not as likely IMO.

One thing I do believe is that with a tube amp it is way more susceptible to what cables you use than a SS amp is, as tube amps in my experience were much more prone to problems with matching the cable impedance than ss amps were.


----------



## Savjac

chashint said:


> That SS amp was modified in such a way that it would be considered defective, in regards to distortion and frequency response.
> Distortion and frequency roll off is generally considered bad, but the countless devoted warm tube sound lovers would not necessarily agree.


Interesting take on the facts and/or information presented. I am always amused to read that certain accepted sciences are considered bad as so many devoted music lovers still honestly desire the sounds of this or that type of equipment over another. I would think that nothing more than choice, neither being right or wrong, just different. Frankly if one were to choose a tube piece of equipment, just rolling the tubes can change the thing from warm to cold as ice in a matter of minutes. So there is really no generalizations in the direction. I have also heard SS equipment that sounded more like syrup than my tube gear so once again, the sound is truly up in the air. 

Should we just stop trying to move forward with electronics and stay where we are because no matter what is done, irrespective of price, it will all sound the same in the end ? Yes i understand, as long as they are working within accepted parameters etc etc. If we use that reasoning we may still be listening to tube electronics. :whistling:


----------



## lcaillo

It would be nice to quantify what moving forward would mean. In terms of current typical measurements and specifications, the concept is rather meaningless. In terms of subjective assessments, it is meaningless to anyone other than one who believes they hear what another does, irrespective of whether or not there is any audible difference or not.

I don't subscribe to the notion that all amps sound the same, but I also think one has to admit that many of the differences that are claimed are likely to be mostly influenced by factors other than actual performance differences.


----------



## ajinfla

Savjac said:


> I would think that nothing more than choice, neither being right or wrong, just different.


Bingo. I agree Jack. It's choice based on preferences. That's it. I really wish folks would just settle on their choice, based on their preference, rather than some absolute, or worse...A is "better" than B...._because_ *I* chose/prefer it.
I don't find one to be generically "better" than the other, just utensils for my pleasure...music.

cheers


----------



## Savjac

lcaillo said:


> It would be nice to quantify what moving forward would mean. In terms of current typical measurements and specifications, the concept is rather meaningless. In terms of subjective assessments, it is meaningless to anyone other than one who believes they hear what another does, irrespective of whether or not there is any audible difference or not. I don't subscribe to the notion that all amps sound the same, but I also think one has to admit that many of the differences that are claimed are likely to be mostly influenced by factors other than actual performance differences.


Very good idea, and thank you for bringing it up
How do we quantify moving forward I as opposed to just recreating molecular shapes? I think once agin it would be in the eyes and ears of the designer and/or buyer.
I doubt many people thought the transistor was a move forward of tubes early on, maybe to the point of heresy. 

I really wish I understood electrical components, theories and construction a whole lot better. A designer has a thought, he/she then puts it to papers and once it checks out proceeds to the build stage, one sample at a time until the design is realized full or becomes another pile of parts. I wonder what the percentage of working prospective prototypes vs junk is. Then once the designer hits the magic box and then starts to zoom in on the minutia of refinement in sound and operation. He/she will most probably start the build with known parts and and components, listen, try other components, listen again and again until the builder decides all is well..

To my somewhat non technical directed mind, I would have to say that with as much care and man hours that oft times goes into the design and build of any given electronic
Product, I would finis it incredible if there were NOT differences between components. it would seem that if such care and attention were put into something, changing any substantive component, or any group of components with other brands or variances would. Y definition change the operation and sound of the component, either for betterorworse. Maybe ??


----------



## ajinfla

Savjac said:


> I would finis it incredible if there were NOT differences between components.


Which is the position of every single rational, science educated person. It's audiophiles that can't grasp that concept, or the position of rationalists.
There are a great many "differences" between components. All explainable (even if believers reject that notion).
There are also a large number of components that are _sonically_ indistinguishable. To *ears*.
That's the part audiophiles simply cannot comprehend. "Different" does not equal *sonically* different.
Sometimes it does (Carver demo et al), sometimes, it does not (piles of controlled tests, including ABX ones).
100% testable, _if_ that is your goal to determine (Sonic/audible).

Otherwise, sit back, relax, enjoy your perceptions. *All* of them. As I do.

cheers,


----------



## BeeMan458

> That's the part audiophiles simply cannot comprehend. "Different" does not equal sonically different.


I'm different. Therefore I'm better. Just ask me. Don't ask my wife, ask ME. My wife wants to trade me in for a model that sounds better.

...


----------



## Savjac

BeeMan458 said:


> I'm different. Therefore I'm better. Just ask me. Don't ask my wife, ask ME. My wife wants to trade me in for a model that sounds better.
> 
> ...


Yeah, better husbands, i dunno, i do ok, as long as i don't do my version of Pagliacci before, during or after dinner.
What does she know right ?? Thanks for the laughter gents, once again i am coming at you from the beautiful green waiting room at the hospital waiting for good news.

AJ, maybe you have it in a nutshell, just enjoy, it would seem disagreements come in upon disagreements, so be it. I most heartily believe in some differences, while others, not so sure about. I also have my reservations about certain tweaks but maybe i do not hear well enough. I also know without a doubt, some groupings of equipment allow me to listen INTO the performance way more than other systems. It would seem after all that whatever i hear or do not hear, becomes my personal pleasure and so be it.

Once we are done paying hospital bills for this and the next round of surgery, I do believe that the equipment i have will be the finest out there at any cost, that is my new story :scratch:


----------



## willis7469

Jack, I do hope your news is good, and I hope your next round of surgeries your last. In the meantime I will send you some positive energy while I will enjoy my sonic ignorance! (Joke lol)
The circular vein of this thread is actually getting humorous. I've never followed a chicken or the egg conversation with this exact question. I've been actually questioning my sanity as to whether or not I can truly hear what I think I do. I have a very discerning ear, and can hear things others around me don't. (Like people talking at a distance, or phones ringing, and just everyday things, not sonic signature stuff). 
My original question was going to ask, who is truly burdened with enlightenment in this case? It seems all of us. Perception is reality. End of story. Since there are obviously 2 sides here, one has to be right. Right? Like Bee said earlier, it's harder for you to prove me wrong, than it is to prove you're right! AJ, basically solidified it for me. I choose, that I am an enlightened one, for if ignorance is bliss, I am happy. 
Good luck Jack!


----------



## chashint

The concept of better is a very interesting subject.
Let's say it is possible to obtain a +/-1dB 10hz-20khz frequency response measured at your listening position and the sound system has the ability to achieve reference level +15dB.
Seems like that system could easily reproduce what the artist/studio/producer intended. 

But is that really audio nirvana?

There is an active thread here discussing house curve with plenty of links to reference material that documents the flat frequency response as being much less audibly pleasing than a frequency response with 12dB+ slope (not necessairly linear) from the low to the high end.


----------



## chashint

Jack,
I too hope for a great outcome with your medical issues.


----------



## BeeMan458

chashint said:


> ...and the sound system has the ability to achieve reference level +15dB.
> Seems like that system could easily reproduce what the artist/studio/producer intended.
> 
> Not trying to split to fine a hair, the idea of reference, at +/- 0dB MVC, one should obtain reference level play. At +15dB MVC, one should be exceeding reference by +15dB which is how THX and the producer/sound mixer intended.
> 
> [quoteBut is that really audio nirvana?


In a way yes but can Nirvana be improved on? Nirvana is a subjective state of mind. We have adjusted our output to serve the wife's need and adjusted to come close to reference level output.......the point.......is a happy wife to be considered audio Nirvana?

(in my own way I'm working at agreeing with you)


----------



## 3dbinCanada

chashint said:


> The concept of better is a very interesting subject.
> Let's say it is possible to obtain a +/-1dB 10hz-20khz frequency response measured at your listening position and the sound system has the ability to achieve reference level +15dB.
> Seems like that system could easily reproduce what the artist/studio/producer intended.
> 
> But is that really audio nirvana?
> 
> There is an active thread here discussing house curve with plenty of links to reference material that documents the flat frequency response as being much less audibly pleasing than a frequency response with 12dB+ slope (not necessairly linear) from the low to the high end.


Audio nirvana depends on what the listener holds important. A person may desire accuracy with a flat frequency response where others may want the high end rolled off. I'm in the former camp.


----------



## 3dbinCanada

Heres wishing you good luck with your surgery as well.


----------



## Tin_Ears

BeeMan458 said:


> I'm different. Therefore I'm better. Just ask me. Don't ask my wife, ask ME. My wife wants to trade me in for a model that sounds better.
> 
> ...


Then stop eating beans and cabbage.


----------



## BeeMan458

Tin_Ears said:


> Then stop eating beans and cabbage.


.....:bigsmile:

(note to self: less beans and cabbage)

...:whistling:


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## chashint

How many of y'all bump up the subwoofer output above what the auto cal thinks is the correct level?

How many of y'all manipulate the EQ levels after calibration to get more bass output or to tame bright sounding speakers?


----------



## willis7469

chashint said:


> How many of y'all bump up the subwoofer output above what the auto cal thinks is the correct level? How many of y'all manipulate the EQ levels after calibration to get more bass output or to tame bright sounding speakers?


The only thing I do is bump the sub out channel when playing music. A sort of house curve, if you will. I did try flattening my sub out channel with the EQ in my onkyo, but it doesn't go low enough for all my troubled spots. I can't run my subs too hot for movies because of my cubic volume. I'm afraid for their safety. ...someday


----------



## BeeMan458

I would never bump with purity. What Audyssey says, is truth.

And then my wife comes into the room and that lie goes out the door.

Audyssey is based on a concept of reference level play and makes the false assumption that what it communicates to the Pre-Pro, will create a condition the amplifier section will be able to replicate. For most, reference level playback is too loud. And although producers and audio engineers mix sound tracks at reference level so one gets all the sonic pudding, most can't eat that much sonic pudding.

Soooooo, our system is EQ'd flat and the volume is set to -17.5dB MVC but to compensate for this adjustment, our house curve is +7dB center channel and +10dB LFE channel.


----------



## Savjac

BeeMan458 said:


> I would never bump with purity. What Audyssey says, is truth.
> 
> And then my wife comes into the room and that lie goes out the door.
> 
> Audyssey is based on a concept of reference level play and makes the false assumption that what it communicates to the Pre-Pro, will create a condition the amplifier section will be able to replicate. For most, reference level playback is too loud. And although producers and audio engineers mix sound tracks at reference level so one gets all the sonic pudding, most can't eat that much sonic pudding.
> 
> Soooooo, our system is EQ'd flat and the volume is set to -17.5dB MVC but to compensate for this adjustment, our house curve is +7dB center channel and +10dB LFE channel.


Interesting, I have no clue what was just said, but it is interesting to try and figure out, 

I think picking and choosing what part of the spectrum we want to hear and what part we don't want to hear, imo somewhat negates the entire concept of having any standards or references. In the end we are telling the so called producers and audio engineers that their ideas of sound stink and we will do it our way. I don't think anyone ever demanded we need to listen at reference levels, nope, that is merely standard that a system SHOULD be able to meet or better to be considered of sufficient volume if one wishes to give it a go. I really do not, but at the same time, i am pretty sure i can meet any of my standards and frankly, those are the only standards that are important in my house. 

Thousands of hours can go into mixing a soundtrack for film, much of which we may never actually enjoy in all is glory. The same can be said for many albums as well, and once again, unless we were there when the recording, playing and final mix down was done, we will never really know what the engineers wanted us to hear, it is only a guess on our part.

Some time ago, my guitar theory teacher and i did an experiment in his recording studio. We made a recording using a set of Yamaha monitors to the point wherein the playback sounded similar to what we were hearing live. Then we took the same mix and mastered it back using a very nice audiophile type set of KEF speakers as monitors. I then took the mixes home and listened to them on my home speakers and what a lesson i learned. One mix was awful, while the other one spoke to what i had heard in the studio. 
What does this say, well to me it says, in 99% of the playbacks at out home, we will never hear what the original artist or engineer intended, only a close proximity of the recording space. This is of course assuming that our equipment is not the same as that being used in the studio.

So it would appear, all bets are off.


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## Savjac

Thank You everyone for the good wishes, my wife is recovering nicely and making the usual demands of me in the hospital room, so that is quite a good sign.

Thank You Gentlemen


----------



## BeeMan458

Savjac said:


> I think picking and choosing what part of the spectrum we want to hear and what part we don't want to hear, imo somewhat negates the entire concept of having any standards or references. In the end we are telling the so called producers and audio engineers that their ideas of sound stink and we will do it our way.


And that is wrong.........how?

My opinion, EQ everything flat, and then add your spin to the sound equation as producers and sound engineers are not demigods.

(this is my opinion)

Yes, we want to hear your wife is healthy and she'll be in the garden tomorrow.

Let her know our prayers are with her.


----------



## Savjac

BeeMan458 said:


> And that is wrong.........how?
> 
> My opinion, EQ everything flat, and then add your spin to the sound equation as producers and sound engineers are not demigods.
> 
> (this is my opinion)
> 
> Yes, we want to hear your wife is healthy and she'll be in the garden tomorrow.
> 
> Let her know our prayers are with her.


Thanks Thomas, however, she will not be in the garden for some time methinks. Spinal surgery can take a bit to heal and then it will be followed up with abdominal surgery to fix a hernia that took place because of surgical scars in that area. One good thing, she looked at me this evening and said that she wins the scar contest from here on out, I agreed. :blink:


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## ajinfla

BeeMan458 said:


> My opinion, EQ everything flat


The question is, where?
EQ'd flat at the LP, will sound unbearably bright. Because the (onset) direct response of the system would have to tilted way up at HF, to sum flat with propagation and room absorption losses. Even worse, we have two ears attached to a head, not a single mic capturing only the pressure component of the soundfield. 
So where would you put the single pressure mic and EQ flat?

cheers


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## gdstupak

If the measurements and corrections are made at the LP, then the response at the LP would be flat. How would they be unbearably bright (unless the system were reproducing unbearably bright signals)?
And moving out of the exact LP does not change the response significantly (in my experience). I can move several inches or several feet any direction and it's not noticeable to my ears. And not noticeable to my analog SPL meter.


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## BeeMan458

ajinfla said:


> The question is, where?EQ'd flat at the LP, will sound unbearably bright.
> cheers


If using a room correction software like Audyssey XT32, why would that be a fact?

Your comment suggest, you have no personal experience with XT32.

...

Do you have personal experience with XT32/SubEQ HT which is based on a single measuring microphone, placed in eight separate locations?

(disclosure: my wife and I have run into a family/emotional/outsider situation that has completely blown up our chi and my way of dealing with it is to get totally blasted)

(it's all good. And with open arms, we're openly inviting a unknown deserving outsider human being, with wife (no kids) into our life, as if a son, to our personal situation)


----------



## ajinfla

gdstupak said:


> If the measurements and corrections are made at the LP, then the response at the LP would be flat. How would they be unbearably bright (unless the system were reproducing unbearably bright signals)?


I just explained it. Lets try again. If the response at the single pressure mic, at the LP is flat, then the onset direct response of the speaker must be tilted up at HF, because 1) HF propagation losses from the speaker to LP, 2) HF losses due to room absorption of the reflections.
Our binaural hearing system is not a single pressure mic. It will very clearly hear that tilted up HF direct response, as bright, unless the listener has significant HF hearing loss or just likes unbearably bright sound.
Its precisely why things like the Brüel & Kjær curves are tapering down at HF.
Psychoacoustics 101. Best to understand it.

cheers


----------



## ajinfla

BeeMan458 said:


> If using a room correction software like Audyssey XT32, why would that be a fact?


Because Audyssey doesn't trump psychoacoustic facts, or negate you statement about "EQ flat". You still haven't answered where. If its at the LP, you're incorrect....unless you like very bright sound.



BeeMan458 said:


> Your comment suggest, you have no personal experience with XT32.
> Do you have personal experience with XT32/SubEQ HT which is based on a single measuring microphone, placed in eight separate locations?


Nope. Not needed to understand very basic hearing physiology or perceptual issues.
Plus this isn't about Audyssey. It's about your "EQ flat" statement. You have to qualify it. Where?

cheers


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## chashint

http://www.hometheatershack.com/for...e-curve-what-why-you-need-how-do.html#post448 

http://www.hometheatershack.com/for...els-hard-knee-house-curve-long.html#post55647


----------



## Savjac

I have discussed, or maybe one could say argued that there are differences between some amplifiers that is audible. Many have chosen the other route, about half and half actually.
I have also read literally hundreds of posts about measurements and reviews from Gene at Audioholics regarding his efficacy and the belief that he is correct in what he does. Here is a nice video of what he believes and why and I feel somewhat elevated. :yes:

http://youtu.be/-ZUCoK4qyls


----------



## gdstupak

I understood the video as supporting 'amplifiers sound the same' when no distortion is present.... which is what many here have supported.
The video hosts make a point that maybe distortion happens much more often than most people believe.


----------



## AudiocRaver

That is pretty much what I heard, too.


----------



## Savjac

gdstupak said:


> I understood the video as supporting 'amplifiers sound the same' when no distortion is present.... which is what many here have supported.
> The video hosts make a point that maybe distortion happens much more often than most people believe.


The video points out that there is no way to determine when the amps will not interact well with either the electronics prior to the amplifier and/or the speakers that follow. No one can accurately predict what an amp will sound like when faced with many different speakers, the Martin Logans being one brand as they dip way down into the single digit range in resistance. Next as not all amps are designed the same, many will react quite different from each other based upon what the designer was trying to accomplish. 

This is why blind tests do not work as the amp is not positioned to drive 20 different sets of loudspeakers attached to the same amplifier. It does involve distortions, inadequate power delivery, inadequate construction and probably hundreds of other options i can't think of. Gene and Hugo are clear on this issue, mid video and they are also quite clear that they do NOT all sound alike.

If, as you do AudioCraver have a top of the line speaker system and you play with different amps,they will react to that load differently and then as such sound different. Try it. 

We cannot add a zillion disqualifiers to this humble question, the title is "Can We Really Hear a Difference Between Amps"? The answer is yes. If there are hundreds of exceptions then we can do this same type of qualifying to anything we have. Do All Movies Look The Same....if they all use Kodak Film, in a Panavision camera, in the daylight, with no out of focus scenes, while played back on ABC projectors onto an XYS screen, 50 meters from the lens, in a room of no more then WWW light in the room fitted with exactly 120 volts on a clean print used no more than one time, with 7 people in the audience all not more than 5'9". See what i mean ?
Because there are so many products down line and up river from the amp, one must get rid of all the exceptions except one or two.


----------



## gdstupak

"_.....the title is "Can We Really Hear a Difference Between Amps"? The answer is yes....._"

If that were the simple question, I would also say 'yes'. But a few qualifiers were mentioned at the beginning of this thread (i.e. distortion).


----------



## primetimeguy

Savjac said:


> This is why blind tests do not work as the amp is not positioned to drive 20 different sets of loudspeakers attached to the same amplifier.


Actually this doesn't prove why blind tests do not work as it would apply to any type of test with this comparison. It is just a matter of properly setting up the test. In this case you would just need 20 separate blind tests, one for each set of speakers. If some tests show a difference and some do not then it may show that it is indeed speaker dependent.


----------



## Savjac

primetimeguy said:


> Actually this doesn't prove why blind tests do not work as it would apply to any type of test with this comparison. It is just a matter of properly setting up the test. In this case you would just need 20 separate blind tests, one for each set of speakers. If some tests show a difference and some do not then it may show that it is indeed speaker dependent.


The presentation that blind tests always end in the same result proves they do not work, they cannot work and they will never work. This is a good test to make those that wish to believe these results feel better about their beliefs without actually going our and trying for themselves. You see, in the audio world, there are truly far more believers than non believers, as proven by the glorious amount of different makes and models. I have been learning for a loooong time now and I truly feel sorry for those that have stopped the quest to find better and cannot hear any differences as the differences can truly be wondrous.


----------



## primetimeguy

Savjac said:


> The presentation that blind tests always end in the same result proves they do not work, they cannot work and they will never work. This is a good test to make those that wish to believe these results feel better about their beliefs without actually going our and trying for themselves. You see, in the audio world, there are truly far more believers than non believers, as proven by the glorious amount of different makes and models. I have been learning for a loooong time now and I truly feel sorry for those that have stopped the quest to find better and cannot hear any differences as the differences can truly be wondrous.


I guess we are on opposite sides of the fence then.  

To me that is like saying because the thermostat in my house always reads 72 degrees it must be broken. 

I'm not saying a blind test is perfect but it takes out a lot of variables that falsely impact a sited test. 

At least I think it brings about the point that if there are differences they are very subtle. It should put to rest those that claim huge differences but then can't back that up in blind test.


----------



## Savjac

primetimeguy said:


> I guess we are on opposite sides of the fence then.
> 
> To me that is like saying because the thermostat in my house always reads 72 degrees it must be broken.
> 
> I'm not saying a blind test is perfect but it takes out a lot of variables that falsely impact a sited test.
> 
> At least I think it brings about the point that if there are differences they are very subtle. It should put to rest those that claim huge differences but then can't back that up in blind test.


Tis true that most differences are not huge, that would most probably point to a defect right off the bat. Differences should be more subtle, at least when price range is similar. I do not think it removes variables, rather it stifles variables. It seems more like riding blind folded in 20 different cars on a perfect road at 55 miles and hour. The differences would be very slight to be sure. Now take those 20 cars on an oval, over rough terrain up hill, down hill, zero to 100 and back to zero. I would guess that by doing these things, the differences in cars would become much more apparent.


----------



## primetimeguy

Savjac said:


> Tis true that most differences are not huge, that would most probably point to a defect right off the bat. Differences should be more subtle, at least when price range is similar. I do not think it removes variables, rather it stifles variables. It seems more like riding blind folded in 20 different cars on a perfect road at 55 miles and hour. The differences would be very slight to be sure. Now take those 20 cars on an oval, over rough terrain up hill, down hill, zero to 100 and back to zero. I would guess that by doing these things, the differences in cars would become much more apparent.


But in your example you didn't change from sited to blind, you changed the circumstances of the test. I would compare your example to testing amps using highly compressed music with no dynamic range and at low volume compared to a test of music that pushes the dynamics and at loud levels.

The only variable a blind test stifles compared to a sited test is your vision. If you are against any other aspect of the test it is not related to blind testing rather the test method in general.

If the test is changed to compare the color red on two TVs and I told you to plug your ears do you think plugging your ears is impacting the test in a negative way?


----------



## Savjac

Well there you have it, as I said, I am quite sorry you feel no differences exist and maybe have not heard them. I can only hope one day you will.


----------



## primetimeguy

Savjac said:


> Well there you have it, as I said, I am quite sorry you feel no differences exist and maybe have not heard them. I can only hope one day you will.


That response doesn't help me. I'm curious as to your honest response.

Do you agree your example maybe wasn't what you wanted to portray? 

I'm curious as to your comments on my TV example as well.

Sure I'm in the camp that doesn't believe differences exist unless they can be measured, but at the same time I'm not convinced we are measuring everything we need to be. So I have an open mind and am trying to better understand the thought process of the other side. Being an EE and a former test method development engineer (not in the audio world however) causes me to have natural thought process and biases that I know I need to overcome in these discussions....so help me.


----------



## J&D

I would think that age is the enemy of the ears and if you cannot hear a difference today that won't improve in a decade or two.


----------



## lcaillo

Savjac said:


> Well there you have it, as I said, I am quite sorry you feel no differences exist and maybe have not heard them. I can only hope one day you will.


I would not be sorry for those who feel there are no differences. I f they enjoy the music without having to bother with which AVR sounds better, I see that as an advantage.


----------



## willis7469

primetimeguy said:


> That response doesn't help me. I'm curious as to your honest response.
> 
> Do you agree your example maybe wasn't what you wanted to portray?
> 
> I'm curious as to your comments on my TV example as well.
> 
> Sure I'm in the camp that doesn't believe differences exist unless they can be measured, but at the same time I'm not convinced we are measuring everything we need to be. So I have an open mind and am trying to better understand the thought process of the other side. Being an EE and a former test method development engineer (not in the audio world however) causes me to have natural thought process and biases that I know I need to overcome in these discussions....so help me.


I have read with great interest some of savjac's comments. I feel the same way he does, on some points. Primetime, I liked your question of plugging the ears to objectify the tv test. I'm sure this would not change the result(lol), but fwiw, I think many ppl now a days listen with their eyes, probably more than their ears. To the point of "the other side", I personally am not a professional engineer, but have conceived, and built many things, including those with electrical components. I really wish I could know what is taught when becoming an EE, because to me, (touching lightly on what you said), I feel like it might be a case of, we hear in color, but measure in black and white, due to measurement capabilities. This may expose my ignorance, as to the true nature of the electrical chain that makes up our systems, but I've been "listening" for a long time, and I just can't subscribe to the black and white idea. But, like you, I'm something of a scientist too, and evidence is evidence. But do we have it all? I'm admittedly struggling with articulation, and cohesion, due to my children in the backround, so that's all I got for now! BTW, I do enjoy this type of thread also. Lots of opinions! :bigsmile:


----------



## primetimeguy

willis7469 said:


> I have read with great interest some of savjac's comments. I feel the same way he does, on some points. Primetime, I liked your question of plugging the ears to objectify the tv test. I'm sure this would not change the result(lol), but fwiw, I think many ppl now a days listen with their eyes, probably more than their ears. To the point of "the other side", I personally am not a professional engineer, but have conceived, and built many things, including those with electrical components. I really wish I could know what is taught when becoming an EE, because to me, (touching lightly on what you said), I feel like it might be a case of, we hear in color, but measure in black and white, due to measurement capabilities. This may expose my ignorance, as to the true nature of the electrical chain that makes up our systems, but I've been "listening" for a long time, and I just can't subscribe to the black and white idea. But, like you, I'm something of a scientist too, and evidence is evidence. But do we have it all? I'm admittedly struggling with articulation, and cohesion, due to my children in the backround, so that's all I got for now! BTW, I do enjoy this type of thread also. Lots of opinions! :bigsmile:


Yep, the engineer in me NEEDS an answer to this. But my take on this is that both sides are just theory at this point. We won't have a final answer until we better understand how the brain works and maybe come up with some new measurement techniques. There is something to be said for how many sounds we actually hear at a given moment yet tend of focus only on certain ones. I have my hearing checked yearly and that is an interesting experience for me (geek engineer). When trying to hear the slightest high pitch sounds I find it hard to block out the noise of my own breathing or the slight movement of the headphones over my ears. Crazy that I never notice those things at any other time.

But all science is based on theory until proven differently. I believe given the measurements we have today and the tests (double-blind ABX) we have today support the idea of all amps sound the same if driven within their specifications). But I'm fully accepting of evidence and other theories against it. It's what makes me tick.


----------



## AudiocRaver

Savjac said:


> Tis true that most differences are not huge, that would most probably point to a defect right off the bat. Differences should be more subtle, at least when price range is similar. I do not think it removes variables, rather it stifles variables. It seems more like riding blind folded in 20 different cars on a perfect road at 55 miles and hour. The differences would be very slight to be sure. Now take those 20 cars on an oval, over rough terrain up hill, down hill, zero to 100 and back to zero. I would guess that by doing these things, the differences in cars would become much more apparent.


Being a "shades of gray" kind of guy, I see some of both sides of these discussions. While typical double-blind tests are intended to eliminate _non-auditory_ factors, I can see Savjac's point that the way they are usually set up - "Here, listen to this 20-second snippet of a track I selected for you" - may also end up only presenting the listener with music samples or comparison conditions that do not allow the difference between the amps to be heard. This is not a fault of having to wear a blindfold (or not being able to see the amps under test) but of the way the test material is selected and presented during the test.

In previous posts to this thread - a year ago or more - one suggestion was to test "blind" - the listener does not know what amp is represented by the A or B button - but also allow the listener to listen any way he wants to. He might listen to amp A with various tracks for a week and then amp B with those tracks for a week and pick amp A for its preferred (to him) sonics, then do the same thing 9 more times, and over half a year if he accurately picks amp A 9 times out of 10, then you could say he can definitely hear a difference between the amps. A tough test to administer - more of a "live-in" approach - but could be done in a scientifically valid way that does not have the test subject feeling limited or stifled by the choice of materiel (the road) or the length of time needed to make his determination.

And hopefully we could figure out a way to do it that only takes minutes or hours, not months.:bigsmile:

On the other side of the coin: There are those who will say, "If I can't hear IN A FEW SECONDS that the expensive amp sounds a LOT BETTER than my AVR, then get it out of my room!" Personality and decision-making strategies enter the picture, too. (Actually, this example fits the above-suggested approach perfectly, it would just get done a lot faster.)


----------



## lcaillo

One must realize that people come to this debate with very different assumptions about what is relevant. To the person who is sure they hear differences, the entire experience is the starting point, and that involves both senses. For the person who wants to quantify the performance, vision and any psychoacoustic matters are not really relevant. 

For the former, I would suggest trying to understand that what we perceive may not be the same as what is actually produced, and in many cases the differences we hear have nothing to do with the actual sound being produced. It has been shown many time that expectation bias can affect perception.

For the latter, I would suggest trying to understand that there might be factors that are not being described in the measurements that are often reported, and that there may be more to the story of identifying differences than the various designs of blind testing might resolve.

Once one identifies the limits of the system within which one is arguing, and understands that the two sides are really in very different domains, we can have much more interesting discussions, IME. And for anyone who believes that there are no limits beyond which any system or perspective fails to be useful in describing a part of that system, I can assure you that you are incorrect. This has also been proven and accepted in science, philosophy, and Mathematics. (Yes, the capitalization is intentional......old math teacher.)

The point here is that there is no simple answer to the question of the thread that is accurate for everyone. But when we talk about what we hear and why in detail, we can learn something. Both sides can learn something. Now whether that helps anyone enjoy the music is another matter. One can make an argument that the kind of brain pounding we do to ourselves is just a distraction. But is sure is fun.


----------



## AudiocRaver

lcaillo said:


> One can make an argument that the kind of brain pounding we do to ourselves is just a distraction. *But it sure is fun.*


Indeed!:clap:


----------



## willis7469

AudiocRaver said:


> Indeed!:clap:


+1


----------



## ajinfla

Savjac said:


> The video points out that there is no way to determine when the amps will not interact well with either the electronics prior to the amplifier and/or the speakers that follow.


Actually, no. It is very much determinable when amps will not interact well with load. As a reader of Stereophile, you know this, as JA mentions this with practically every speaker review.



Savjac said:


> This is why blind tests do not work


As I just pointed to you previously, they do..and rather well.
http://www.hometheatershack.com/forums/home-theater-receivers-processors-amps/75330-best-flagship-v-receiver-38.html#post778914



Savjac said:


> as the amp is not positioned to drive 20 different sets of loudspeakers attached to the same amplifier.


There is absolutely no reason why this couldn't be done, but there is an obviously good reason why it isn't.
Blind tests are done for specific claims and objectives, not endless catch-alls.
Once again, no one every claimed it is impossible for amps to misbehave. But *specific* claims by audiophiles about A sounding different from B or C in *their* system is easily confirmed or refuted and has been done so. Be it amps, cables, widgets and whatnot.



Savjac said:


> Gene and Hugo are clear on this issue, mid video and they are also quite clear that they do NOT all sound alike.


If driven to non-linear behavior. You make the presumption this is the case for "millions". As evidenced by....?



Savjac said:


> Because there are so many products down line and up river from the amp, one must get rid of all the exceptions except one or two.


Nope, not to assert that SS (and many tube) amps are indistinguishable to human ears, unless "sound" is created by non-linearity or design. Or "other" confounding factors are introduced.
If there is evidence to the contrary, present it. And no, "I heard it, I said so" doesn't count.

cheers


----------



## J&D

AJ makes some very good points and to be clear I am definitely in the camp of no audible differences when amps are running within their limits. Thinking about this a bit more brings me back to when I swapped out my amps last fall. My trusty (of 25+ years) two channel Citation 22 decided to start humming loudly in the left channel so I opted for a 5 channel amp to replace it and my three channel Monster Sig. The Citation powered a pair of those "hard to drive" Kappa's for many years before being relegated to HT duty. 

When installing the new replacement multi-channel amp I could clearly hear low level noise and hiss when the system was idling. Much higher levels than with my other two amps which were completely silent. Playing movies and music at normal listening levels it was undetectable but obviously it was still there - just masked by the high level program material. I decided to take the time to work on eliminating as much of this noise as possible and it took quite a lot of grounding work to get the system nearly as quiet as it was with my other amps.

Playing back all sorts of program material yielded the same results to my ears. Even when I could reproduce the higher levels of noise (essentially raising the noise floor of the system). Normal playback still sounds exactly the same. My point being, there seems to be a lot of argument about measuring very low levels of noise and how important that amp spec is on the final product. In my case, I did not need to measure the noise as I could easily hear it and with some grounding work nearly eliminate it completely. 

From my perspective, even this clearly audible level of noise made no difference whatsoever when listening to program material at normal levels even when my brain was "pre-wired" to hear it. 

JD


----------



## ramchip0007

I just swaped a Nakamichi PA5 amp in place of the amp in my Yamaha rxz1 and can tell a large change. After reading this post am wondering why ? Maybe the Yamaha clips easy and is the cause. If all the amps sound the same why pay for a class a or a/b when class d are so cheap? Then why would they even make any amp but a class d ? I am sorry but something sounds fishy . I have herd that class d is for driving subs and not good for the upper end. I think a class h sounds like class a in till cranked up inot sure if class d works this way. Now I wonder if my jbl 18's sound better than my sono tube because I my be clipping the amp with the sono tube because the sub needs more power than I am able to give it. If an Inuke class d would sound as good as my Nakamichis I could just sell them buy two nu46000's and have about $600 left over. And I would save on my power bill.


----------



## 3dbinCanada

ramchip0007 said:


> I just swaped a Nakamichi PA5 amp in place of the amp in my Yamaha rxz1 and can tell a large change. After reading this post am wondering why ? Maybe the Yamaha clips easy and is the cause. If all the amps sound the same why pay for a class a or a/b when class d are so cheap? Then why would they even make any amp but a class d ? I am sorry but something sounds fishy . I have herd that class d is for driving subs and not good for the upper end. I think a class h sounds like class a in till cranked up inot sure if class d works this way. Now I wonder if my jbl 18's sound better than my sono tube because I my be clipping the amp with the sono tube because the sub needs more power than I am able to give it. If an Inuke class d would sound as good as my Nakamichis I could just sell them buy two nu46000's and have about $600 left over. And I would save on my power bill.


Amps will sound different from one another when approaching or going beyond their intended/designed power delivery. No one is arguing that fact. The arguement assumes that amps operating well within their intended/designed power delivery will sound the same.


----------



## TheHammer

lcaillo said:


> One must realize that people come to this debate with very different assumptions about what is relevant. To the person who is sure they hear differences, the entire experience is the starting point, and that involves both senses. For the person who wants to quantify the performance, vision and any psychoacoustic matters are not really relevant.
> 
> For the former, I would suggest trying to understand that what we perceive may not be the same as what is actually produced, and in many cases the differences we hear have nothing to do with the actual sound being produced. It has been shown many time that expectation bias can affect perception.


An interesting series of comments. I agree with what you say, except I would likely change "in many cases the differences we [are convinced we] hear have nothing to do with the actual sound being produced." 




lcaillo said:


> For the latter, I would suggest trying to understand that there might be factors that are not being described in the measurements that are often reported, and that there may be more to the story of identifying differences than the various designs of blind testing might resolve.


Do you have any idea why blind testing would not resolve any real differences? I know that this have been a lively debate, that blind or ABX testing somehow obscures real differences.

I am convinced that ABX testing is a perfectly valid way to discover if 'the differences we are convinced we hear' are really there. However, I am open to the possibility that ABX testing is somehow obscuring subtle differences - even though I do not believe it to be true. 

I come from a Chemistry background. When we do testing of samples, we always include both a known positive and a known negative. The purpose was to insure that our tests are not giving false positives nor false negatives. I once got in a spirited discussion with Tom Nousaine (who just passed away - he will be missed). He was always secure in his feelings of the infallibility of ABX testing. I pressed him on the need to include a sample where the difference was audible, to insure that the ABX test did not obscure the real differences. Of course the difficulty would be in designing such a positive result, and what type of distortion and level might be appropriate. One type of distortion (IM, even order harmonic, odd order harmonic, slew, etc.) could be obscured while another type would not. :dontknow:

I know just enough statistics to be dangerous. I have never felt comfortable in establishing a certain hurdle level. For example, if we select a 95% probability that the difference is real, does that mean that 5% of the time we will get a false positive? For drug testing, a 98% or 99% threshold might be selected. If we select those higher hurdles and reach 'only' the 95% level, then we reject the hypothesis that the differences can be heard. Yet doesn't that mean that there is a 95% probability that there is a detectable difference. There is your challenge for you, Mr. Mathematician! 

Somehow, I lost my copy of the original Stereo Review ABX study. It had a great explanation of the statistical analysis. I will have to dig through the 1989 Stereophile study again. Nice way to spend a Saturday night. :nerd:


----------



## ramchip0007

A lot of you have herd more amps than I have but I would like to say a few things . Amps are not all the same when it comes to how high khz and how low MHz they can go. when comparing the power output of amps some are over rated and some are underrated . I think most of us will agree that the sound is distorted when an amp is pushed past a given point , and maybe receivers are more over rated in wpc than most separate amps , Ya that receiver might push out 170 wpc but how clean will it be at that level. I had a ht in a box that said it put out like 1100 watts LOL:rofl: . RMS is not apples for apples. What about damping factor ? Maybe my receiver and my separate amp sound the same at volume level 2 but I don't listen at level 2 I crank it up ,like a lot of people ! Just my 2cents.


----------



## Savjac

Sound is different to everybody, and the rating of those HTIB are truly unlawful in the highest, but what the . I have been doing a bit of experimentation of late in changing out certain items in amps and i can say without question that changing just one item changes the sound of the amp. Sometimes to a great degree and sometimes hardly at all. I am very clear here that if in my home, with my average system, can change a part in an amp and hear the differences so clear, then once again, i am deeper in the belief that unless all the amps in question have the exact same components and topology, there will be differences. It seems so obvious but must not be.


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## ajinfla

TheHammer said:


> However, I am open to the possibility that ABX testing is somehow obscuring subtle differences - even though I do not believe it to be true.


Hi Hammer, 
I've seen that hypothesis raised, but never an answer to my subsequent question.
If ABX has "missed" or obscured an audible difference, what specific method was used to determine this miss?
MUSHRA? Triangle?
Inevitable, the person posing the hypothesis has never heard of either (or any other controlled method), goes mute, or.....admits that their determination method was "Well, I heard it".
Or maybe something equally preposterous like "Long term" sighted, uncontrolled "listening", "Cognitive dissonance" etc, etc.
I not saying things can't be missed in a poorly designed "ABX", but that is hardly condemnation of the entire scientific method for discrimination testing.

cheers


----------



## ajinfla

Savjac said:


> I have been doing a bit of experimentation of late in changing out certain items in amps and i can say without question that changing just one item changes the sound of the amp.


Do tell 
I don't think anyone would argue that fiddling about with amp internals can't change their "sound"!

cheers


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## Savjac

Good Morning AJ, 
How are you these days ??


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## TheHammer

ajinfla said:


> Hi Hammer,
> I've seen that hypothesis raised, but never an answer to my subsequent question.
> If ABX has "missed" or obscured an audible difference, what specific method was used to determine this miss?
> MUSHRA? Triangle?
> Inevitable, the person posing the hypothesis has never heard of either (or any other controlled method), goes mute, or.....admits that their determination method was "Well, I heard it".
> Or maybe something equally preposterous like "Long term" sighted, uncontrolled "listening", "Cognitive dissonance" etc, etc.
> I not saying things can't be missed in a poorly designed "ABX", but that is hardly condemnation of the entire scientific method for discrimination testing.
> 
> cheers


Hello AJ.

I believe that any testing that does not include positive and negative controls to validate the system leaves itself open to criticism that the test methodology affects the results. When people are convinced that there is a sound difference between amplifiers, yet are unable to verify their expected results using ABX, they blame the test.

There is evidence that ABX does not obscure real differences in sound. 

http://home.provide.net/~djcarlst/abx_data.htm

If ABX testing masks real audible differences, then we would not have any "different" results.

Yet, even when ABX distortion testing, 3% THD drops to a 64% correct result. Is 3% THD close to the threshold of THD detection? Or is the ABX test itself obscuring what under other circumstances would be an obvious audible difference? 

Are certain distortions more likely to be affected (masked) by ABX than others?

To refute those claims, one would have to identify the threshold of audibility of many different types of distortions, then set up a ABX test and see if the result is as expected. That would be a herculean task.

http://www.stereophile.com/asweseeit/673awsi/

http://www.madronadigital.com/Library/AudibilityofSmallDistortions.html



ajinfla said:


> I not saying things can't be missed in a poorly designed "ABX", but that is hardly condemnation of the entire scientific method for discrimination testing.


Agreed (enthusiastically).

Take care.


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## ramchip0007

If we can agree that if wpc ratings from different companies are not accurate because some company's use different ways to test for wpc , than maybe its the same for thd . You would think they all would have to test the same way to protect the consumeraddle: .


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## lcaillo

Actually, THD measures are very similar because most of the companies use very similar test equipment. If they tell you at what power and frequency it was measured you can pretty much compare apples to apples. The issue, IMO, is how well do the distortion measures that are typically used characterize differences in sound. Not very well, IMO.


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## ramchip0007

I wonder when they test for thd if they all use the same load and other variables. when looking at a amps output with an oscilloscope when the amps starts to clip they all don't act the same way even amps of the same class ,A AB, H, D . Maybe someone with more knowledge: nerd: with this will chime in. I was doing some research on the inuke's THD and found this. goggle: Behringer inuke NU6000 vs KAM KXD7200 bench tested


----------



## TheHammer

lcaillo said:


> Actually, THD measures are very similar because most of the companies use very similar test equipment. If they tell you at what power and frequency it was measured you can pretty much compare apples to apples. The issue, IMO, is how well do the distortion measures that are typically used characterize differences in sound. Not very well, IMO.


There is some thought that THD is a misleading measure. THD is dominated by the lower harmonics and they are considered to be less audible than higher order harmonics. An amp with lower THD could have higher levels of higher order harmonics that could be more audible, yet the THD spec does not reflect this distribution. This maybe more of an issue with tube amps than transistor (SS) amps - I do not know this as a fact.

Perhaps a better measure would be HD measurements, subtracting out the lower harmonics. Or considering only the odd order harmonics.

IM distortion (IMD) may be more audible than lower order HD, at least for some forms of music according to some posts on the web.

http://www.nutshellhifi.com/library/FindingCG.html

The above links references tube circuits. I am not endorsing its conclusions - I find his analogy to mass spec inaccurate and misleading, but then he knows more about electronics than I do.

http://www.tungsol.com/tungsol/html/faqs14.html

The above addresses HD in tube and transistor amps when driven beyond their limits, into clipping. This does not address the differences in THD when amps are operated at lower (normal) levels.

If anyone can find a source of THD measurements of modern transistor amps, with a breakdown of the different harmonics, that would be helpful. Also, a study of the audible thresholds of the different harmonics would be interesting. I will keep digging.


----------



## ajinfla

Savjac said:


> Good Morning AJ,
> How are you these days ??


Doing well...and you? Hope the Mrs is well also.
You haven't gone to the dark side (or is that light) of tubes have you? What stuff you changing?

cheers,


----------



## Savjac

ajinfla said:


> Doing well...and you? Hope the Mrs is well also.
> You haven't gone to the dark side (or is that light) of tubes have you? What stuff you changing?
> 
> cheers,


I am doing well, tired but well. The Mrs is recovering, but she has what looks to be a zillion staples in her tummy but the outlook is positive, Thank You.

Since I am playing nurse maid 24/7, yes I have been going to the light side a bit and changing out some tubes, and i have been playing with some speaker crossover components in order to learn a bit of how things work and interact. Its very exciting.
The speakers i am playing with are from GR Research and i made them with the crossovers temporarily outside the cabinets. This is fun but sooo frustrating.


----------



## Tonto

Hey Savjac, glad to hear the Miss's is recovering. If she doesn't have one, consider an abdominal binder. Its like a 12" wide, elastic belt that velcro's together. It holds/supports your abdomen & helps with pain control when moving around.

http://www.braceplanet.com/SAI-10-Elastic-Abdominal-Binder.html

You would think that squeezing the stomach after surgery would increase pain, but patients tell me these things really help.


----------



## Savjac

Thank you Tonto and yes we have a couple of those. I agree it sounds odd but works. Of late her best friend has been a good sturdy pillow she holds there and as i understand it there is nothing that can really break in way of the surgery but you are spot on, the pain when coughing or sneezing or moving can be outrageous. 
Thank you for your thoughts.


----------



## Krelldog

Looks like the poll shows an even split between the 2 options. In my experience it's the speakers that make the MOST difference in a system....which I'm sure everyone will agree on. Buy yourself a good quality amp and stay focused on upgrading speakers. Enjoy fellas!


----------



## NBPk402

Here is an interesting video that addresses the subject (around 4 minutes in).


----------



## littlejohn74

ellisr63 said:


> Here is an interesting video that addresses the subject (around 4 minutes in).
> Audio Myths Workshop - YouTube


The most interesting thing about that link is how it highlights what little understanding we have of the human brain.

SPL, THD, Freq response etc etc are all just numbers... or data if you will. 
It is generally accepted that data is useless until it is processed into information. It is how the data is processed in each individual's head as to what will be perceived as real or not.

Another interesting point to keep in mind is that there was a time when "science" could not explain why some people were "unable" distinguish colours correctly.

I don't mean to offend anyone and I'm not suggesting that those who cannot hear a difference in amplifiers in some way have defective hearing.
I'm merely postulating that there is enough evidence to suggest that irrespective of all the ABX testing thus far, the results are inconclusive.


----------



## 3dbinCanada

littlejohn74 said:


> The most interesting thing about that link is how it highlights what little understanding we have of the human brain.
> 
> SPL, THD, Freq response etc etc are all just numbers... or data if you will.
> It is generally accepted that data is useless until it is processed into information. It is how the data is processed in each individual's head as to what will be perceived as real or not.


Yes and no... Its true that people interpret sound differently and that no two people may hear exactly alike. We have our own frequency response curves that we carry with us. However, human hearing has been modelled and frequency response has been accessed to run between 20Hz to 20KHz. Lets take a look at Klipsch speakers with their horn loaded tweeters. More people than not do not like Klipsch speakers because they find them overly bright due to the high frequency emphasis created by the horn. If one looked at their response curves, one would see a rise in output in the treble region compared to the mids. That is regardless of what amp you pair them with except for maybe tube amps. Tube amps are a different beast altogether. My point is that the raise in treble frequencies relative to the other frequencies are heard and most don't like it. People find it the hot treble fatiquing. There is a correlation between data and likes and dislikes. That's why its so important to audition to see what best fits your internal frequency response curves.


----------



## TheHammer

littlejohn74 said:


> The most interesting thing about that link is how it highlights what little understanding we have of the human brain.
> 
> I don't mean to offend anyone and I'm not suggesting that those who cannot hear a difference in amplifiers in some way have defective hearing.
> I'm merely postulating that there is enough evidence to suggest that irrespective of all the ABX testing thus far, the results are inconclusive.


Quoted from the video as accurately as I could manage:

"If you have reasons to assume things are different… or if you think everything sounds the same, you will steer yourself that way."

"What this basically means is that you have to do a blind test." 

"If you know what the two things are, your brain is going to use that information."

He then went on to tell about a faked non-blind test where the correspondents selected their preconceived preference as the best.

"This sounds warmer, this sounds clearer… all that switch did was go 'clack clack'."

"You have to isolate the subject from this sort of information."

This is further evidence that all of our listening, where we are aware of the product under test, provides nothing but biased, misleading, useless information.
The only way to test to insure that our biases do not change the result is through blind testing.


----------



## littlejohn74

TheHammer said:


> Quoted from the video as accurately as I could manage:
> 
> "If you have reasons to assume things are different… or if you think everything sounds the same, you will steer yourself that way."
> 
> "What this basically means is that you have to do a blind test."
> 
> "If you know what the two things are, your brain is going to use that information."
> 
> He then went on to tell about a faked non-blind test where the correspondents selected their preconceived preference as the best.
> 
> "This sounds warmer, this sounds clearer… all that switch did was go 'clack clack'."
> 
> "You have to isolate the subject from this sort of information."
> 
> This is further evidence that all of our listening, where we are aware of the product under test, provides nothing but biased, misleading, useless information.
> The only way to test to insure that our biases do not change the result is through blind testing.



Perhaps, but I think you've missed the point. Which is, similar to all other senses, auditory processing by the human brain is intermixed with other sensory cues.
For example, taste is heavily influenced by olfactory cues. Does this mean there is no difference between coffee and tea because in ABX testing where the olfactory cues are removed no one can taste the difference?

I'm not sure what your experience or qualifications are with regard to statistical analysis, but I'm sure anyone who has conducted studies of any sort will agree, that it is not at all difficult to manipulate data to prove a particular point.

I have often seen people post link after link to blogs or articles which attempt to prove that in ABX testing, no one has been able to show that there is an audible difference between amplifiers.
Whilst I'll admit they have been very interesting reads, not one of the articles I've seen could be considered a scientific experiment. As such, the results are more conjectural than fact.


----------



## ajinfla

TheHammer said:


> Quoted from the video as accurately as I could manage:
> 
> "If you have reasons to assume things are different… or if you think everything sounds the same, you will steer yourself that way."
> 
> "What this basically means is that you have to do a blind test."
> 
> "If you know what the two things are, your brain is going to use that information."
> 
> He then went on to tell about a faked non-blind test where the correspondents selected their preconceived preference as the best.
> 
> "This sounds warmer, this sounds clearer… all that switch did was go 'clack clack'."
> 
> "You have to isolate the subject from this sort of information."
> 
> This is further evidence that all of our listening, where we are aware of the product under test, provides nothing but biased, misleading, useless information.
> The only way to test to insure that our biases do not change the result is through blind testing.


Testing 1 2 3
Test of forum software, no one panic...


----------



## lcaillo

TheHammer wrote:
"This is further evidence that all of our listening, where we are aware of the product under test, provides nothing but biased, misleading, useless information. The only way to test to insure that our biases do not change the result is through blind testing."

"useless information" maybe to those who want objective results, but blind testing may be just as useless to others. The problem with this debate is that the starting assumptions are different for both sides. You cannot have a logical outcome that is valid unless the underlying assumptions are the same and the question is well posed. 

The question of whether there are meaningful differences objectively is meaningless to someone who buys a Krell amp in most cases. The reasoning behind that purchase is meaningless to most who demand objective results. That does not mean that we cannot have a discussion and debate the matter, but making statements like "useless information" does not show respect for another perspective.


----------



## TheHammer

littlejohn74 said:


> I'm not sure what your experience or qualifications are with regard to statistical analysis


I have a graduate degree that required courses in statistics. I got an 'A'. Thanks for asking. 



littlejohn74 said:


> For example, taste is heavily influenced by olfactory cues. Does this mean there is no difference between coffee and tea because in ABX testing where the olfactory cues are removed no one can taste the difference?


If you are describing blind testing performed on amps as being a situation analogous to removing 'olfactory cues', I would respectfully disagree. Knowing what amplifier is under test has a profound effect on our opinion. Removing that knowledge and making it a blind test, cannot affect the sound. The video I quoted included a story where the subjects thought they knew what was under test and that profoundly distorted their opinions.

No matter how hard we try, we are unable to separate our preconceptions from our judgements. When a reviewer pronounces the amp as having a certain 'sound', I ignore that section of the review. I believe that these reviews mislead consumers into making choices based on invalid information.



littlejohn74 said:


> Whilst I'll admit they have been very interesting reads, not one of the articles I've seen could be considered a scientific experiment. As such, the results are more conjectural than fact.


Can you please support that statement? I am curious as to why you think that these studies should not be considered as scientific. Thanks.



lcaillo said:


> The problem with this debate is that the starting assumptions are different for both sides. You cannot have a logical outcome that is valid unless the underlying assumptions are the same and the question is well posed.


I thought the question here was "Can we really hear a difference between amps". If we cannot agree on the definition of this question, then this thread cannot serve a purpose and we are spending our time with perfectly valid responses to, in a way, different questions.

If there is an underlying assumption that what we actually hear is affected by what we see, then that is another interesting debate. Understanding what what we mean by 'hearing' is crucial. Blind testing has always assumed that, to use the previous poster's analogy, what we actually taste is not affected by knowing what we are tasting. It is the Coke vs. Pepsi challenge where knowing in advance what is being consumed affects the results. But knowing or not knowing does not affect the taste of the product, does it? Can knowing what amp is under test affect the sound? 



lcaillo said:


> The question of whether there are meaningful differences objectively is meaningless to someone who buys a Krell amp in most cases. The reasoning behind that purchase is meaningless to most who demand objective results. That does not mean that we cannot have a discussion and debate the matter, but making statements like "useless information" does not show respect for another perspective.


Point taken. I did not intend to insult anyone, nor did I attack an individual. If anyone was personally offended, I apologize. 

Yet I believe that any review from any source that knows the product under test cannot help but be profoundly affected by their preconceived opinions about that product.

If one rejects blind testing and accepts subjective testing as the valid means of ranking amplifiers, then why the inconsistency of amplifier reviews? If, for example, Sony amplifiers always sound [insert description], why aren't all subjective reviews of Sony the same? If they are not the same, are these reviews useful?

One of the crucial measures of validity is reproducibility. By that measure, subjective reviews fail the validity test.


----------



## vidiot33

Maybe another way to frame this discussion would be to ask not about differences in amps, but PERCEIVED differences, a very different question. Our senses can and are informed by our preconceptions, but a valid point in the other camp is the ability of at least some to hear real verifiable differences between products.


----------



## TheHammer

vidiot33 said:


> Maybe another way to frame this discussion would be to ask not about differences in amps, but PERCEIVED differences, a very different question. Our senses can and are informed by our preconceptions, but a valid point in the other camp is the ability of at least some to hear real verifiable differences between products.


That would be interesting. That would allow everyone to define their own reality. And everyone would be correct.


----------



## littlejohn74

TheHammer said:


> I have a graduate degree that required courses in statistics. I got an 'A'. Thanks for asking.
> 
> Cooly, then you know what I'm talking about when it comes to stats.
> 
> If you are describing blind testing performed on amps as being a situation analogous to removing 'olfactory cues', I would respectfully disagree. Knowing what amplifier is under test has a profound effect on our opinion. Removing that knowledge and making it a blind test, cannot affect the sound. The video I quoted included a story where the subjects thought they knew what was under test and that profoundly distorted their opinions.
> 
> No matter how hard we try, we are unable to separate our preconceptions from our judgements. When a reviewer pronounces the amp as having a certain 'sound', I ignore that section of the review. I believe that these reviews mislead consumers into making choices based on invalid information.
> 
> 
> 
> Can you please support that statement? I am curious as to why you think that these studies should not be considered as scientific. Thanks.
> 
> I've not seen any evidence from any of the links that would state otherwise. None of the articles provide detail on experimental methodology.
> From the information published the only conclusion I am able to draw is that they are no different to you or I conducting a random ABX test at home with no controls.
> Eg:. I can say that after 100hrs of ABX testing, with an random sample of 150 people. Not one person was able to hear any difference.
> What I neglect to say is that during all of the testing, there was a 15 kilotonne pole driver operating all day. The random sample was chosen from a group of who had hearing impairment which ranged from mild to severe.
> I'm exaggerating of course, but you get the point.
> 
> I thought the question here was "Can we really hear a difference between amps". If we cannot agree on the definition of this question, then this thread cannot serve a purpose and we are spending our time with perfectly valid responses to, in a way, different questions.
> 
> If there is an underlying assumption that what we actually hear is affected by what we see, then that is another interesting debate. Understanding what what we mean by 'hearing' is crucial. Blind testing has always assumed that, to use the previous poster's analogy, what we actually taste is not affected by knowing what we are tasting. It is the Coke vs. Pepsi challenge where knowing in advance what is being consumed affects the results. But knowing or not knowing does not affect the taste of the product, does it? Can knowing what amp is under test affect the sound?
> 
> 
> 
> Point taken. I did not intend to insult anyone, nor did I attack an individual. If anyone was personally offended, I apologize.
> 
> Yet I believe that any review from any source that knows the product under test cannot help but be profoundly affected by their preconceived opinions about that product.
> 
> If one rejects blind testing and accepts subjective testing as the valid means of ranking amplifiers, then why the inconsistency of amplifier reviews? If, for example, Sony amplifiers always sound [insert description], why aren't all subjective reviews of Sony the same? If they are not the same, are these reviews useful?
> I'm not sure if "rejecting" blind tests would be a fair comment. I just find it difficult to draw definitive conclusions from experimental results where the details and methodology has not been made available. Or published in the same article.
> 
> One of the crucial measures of validity is reproducibility. By that measure, subjective reviews fail the validity test.
> I think it would be fair to say that not all reviews are conducted under the same conditions. ie. equipment, speakers, rooms etc etc.


comments in red


----------



## littlejohn74

vidiot33 said:


> Maybe another way to frame this discussion would be to ask not about differences in amps, but PERCEIVED differences, a very different question. Our senses can and are informed by our preconceptions, but a valid point in the other camp is the ability of at least some to hear real verifiable differences between products.


Your comments raise a very interesting point. Which is... this thread is trying to objectively quantify a very subjective matter. Music by its nature is very subjective, which will in itself have an affect on the results of any ABX testing.
I wonder if anyone has ever done any ABX testing with pink noise.


----------



## Savjac

I suppose it would be too much to just listen ??
Get some different products and listen, if you can hear no difference than there you have it. If you can hear some difference then .....well there you have that.
The poll is 50/50 about what one would expect. 

I feel very lucky to be able to hear differences in many audio things.


----------



## vidiot33

littlejohn74 said:


> Your comments raise a very interesting point. Which is... this thread is trying to objectively quantify a very subjective matter. Music by its nature is very subjective, which will in itself have an affect on the results of any ABX testing. I wonder if anyone has ever done any ABX testing with pink noise.


Exactly! No matter how this issue is addressed, there will be disagreement. There is a sense that not only is perception of the passage of time personal, but the subjective experience of listening to music is also individual and unique, however we may try to objectify and quantify this personal interpretation, allowing of course, for certain elements of the experience to be somewhat universal.


----------



## AudiocRaver

Good discussion. And thank you all for keeping it civil.

Here is what I would like to see accomplished in this area:

The ability to work with someone who claims he CAN hear a difference between certain amps and determine objectively, _and to that listener's satisfaction by their own criteria,_ that he either can or cannot actually hear that difference.
The ability to work with someone who claims he CAN NOT hear a difference between certain amps and show him that he actually CAN.
There seems to be a lot of insistence that the objective and the subjective realms of perception and hearing are mutually exclusive, or that one automatically supersedes the other. I see no reason why this must be so, why we can not find ways in our evaluations and tests to satisfy the wants, needs, and requirements of both realms, have them "get along together," so to speak. But... that is just my opinion.


----------



## Krelldog

vidiot33 said:


> Exactly! No matter how this issue is addressed, there will be disagreement. There is a sense that not only is perception of the passage of time personal, but the subjective experience of listening to music is also individual and unique, however we may try to objectify and quantify this personal interpretation, allowing of course, for certain elements of the experience to be somewhat universal.



Well said, disagreement is inevitable when it comes to this topic. The poll is a 50/50 split.

I'm curious what a poll would reveal about, " Do all Processors sound the same ? "

hoping the XMC-1 is HUGE success...if it delivers, Emotiva's reputation will move many rungs up the ladder. Just awaiting for the review to validate an immediate purchase

Have a Happy Halloween fellas!


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## vidiot33

Interesting thought. I tend to believe that it would be easier to detect differences in preamps/processors than amps.


----------



## chashint

Processors certainly have much more potential to sound different than output amplifiers.


----------



## Lumen

You said it! And you can say that again! 

Some amps are allegedly voiced with colorations intended to please certain listeners. In my experience, the audio press would have you believe differences between such amps are night and day. Actually, the term is becoming a cliche to the point where some reviewers acknowledge the differences as being slight in the overall scheme of things. But I digress and rule on as usual.

When it comes to processors, I believe "voicing" if any, has much more impact on their perceived sound. Choice of ADC chip and supporting circuitry certainly account for some differences. But I believe the overriding factor falls in the realm of creativity and quality of the analog output stage. Sometimes we forget that analog still lives among us and like it or not, it affects what we here, subtle or not. 

Can you separate your analog output stage from your processor for comparison reasons? Tough job. I may have mixed topics with half Outboard ADC's and half HTC Pre/Pro's, so for that I apologize. Which are we talking about exactly?


----------



## Lumen

Yikes! Trying to write and correct post on iPhone while riding in back of bouncing bus. Won't do this again!

Writing again to correct previous post... No, I don't "rule". I meant to say "ramble". 

Sorry.


----------



## Krelldog

I was referring to the audible differences between a dedicated pre/pro and a standard AVR....for movies.


----------



## chashint

The pre/pro is where the audio decoding, bass management, delays, speaker levels, and room correction is handled.
The mainstream AVRs are generally leading the way into every new technology or iteration of technology where the boutique brands product cycles are much less frequent.
I personally think the pre/pro is much more likely to have a unique sound vs the power amp which simply amplifies whatever is fed into it.


----------



## vidiot33

It should not come as a surprise that people hear differently. After all, sense of taste is all over the map. Some people love hot spicy food; to me, it's just overpowering and painful. Some love the sound of horns, e.g., Klipsch, while others (including me) will run for the exits. If variability exists in other senses, why not in hearing?


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## Krelldog

I agree with ya...variability does exist in other senses, some much more than others, hearing included.

But, provided we all have 20/20 vision, variability in sight may yield the least. I wonder where hearing would fall on that list?

Cheers,
B


----------



## vidiot33

Krelldog said:


> I agree with ya...variability does exist in other senses, some much more than others, hearing included.
> 
> But, provided we all have 20/20 vision, variability in sight may yield the least. I wonder where hearing would fall on that list?
> 
> Cheers,
> B


I would agree with your comments about vision. You don't have huge debates over what looks good and there is at least general agreement on the part of videophiles that THX standards are a good thing. I'd love to see studies done that quantify this, but I'm not aware of any pending research. I doubt we'll ever see a set of standards for what sounds good that the majority of audiophiles will sign on to. I would guess that hearing would come after sense of taste for variability, but it's just a guess.


----------



## TheHammer

littlejohn74 said:


> littlejohn74 wrote: View Post
> I'm not sure what your experience or qualifications are with regard to statistical analysis
> 
> TheHammer wrote:
> I have a graduate degree that required courses in statistics. I got an 'A'. Thanks for asking.
> 
> Cooly, then you know what I'm talking about when it comes to stats.


Actually, I don't. Statistics are mathematics. Arguing against them is akin to arguing that 3+3 does not equal 6.

http://en.wikipedia.org/wiki/Student's_t-test

The controversy usually arises as to what is statistically significant. This can be an issue when the result is close to the threshold.

http://en.wikipedia.org/wiki/Statistical_significance

Many get a bad impression of statistics because of polls (especially political) where a small difference in the wording and change the result. Other times, people confuse statistics with forecasting which has taken on increased controversy with the global warming debate. Statistics of the type that are used in listening tests does not forecast. 

Or people who use statistics as proof of cause and effect - which is a mistaken conclusion, not an indictment of statistics as a science.



littlejohn74 said:


> littlejohn74 wrote: View Post
> Whilst I'll admit they have been very interesting reads, not one of the articles I've seen could be considered a scientific experiment. As such, the results are more conjectural than fact.
> 
> Can you please support that statement? I am curious as to why you think that these studies should not be considered as scientific. Thanks.
> 
> I've not seen any evidence from any of the links that would state otherwise. None of the articles provide detail on experimental methodology.
> From the information published the only conclusion I am able to draw is that they are no different to you or I conducting a random ABX test at home with no controls.
> Eg:. I can say that after 100hrs of ABX testing, with an random sample of 150 people. Not one person was able to hear any difference.
> What I neglect to say is that during all of the testing, there was a 15 kilotonne pole driver operating all day. The random sample was chosen from a group of who had hearing impairment which ranged from mild to severe.
> I'm exaggerating of course, but you get the point.


I don't see any evidence to support your statement. Please provide some. 

Many (but I am sure not all) ABX testing has been done under controlled conditions that are 'scientific' in their methodology. No pole driving was done nearby.

In order to be an accepted study, it must be published in peer reviewed publication. Then others must be able to duplicate the results. Research generally falls apart when others are unable to obtain the same results. ABX testing with amplifiers has been reproduced repeatedly, so it stands up to scientific scrutiny. 

There are many different studies available on the Internet, if you want to read them. 
Here are a few scientific articles:

http://people.xiph.org/~xiphmont/demo/neil-young.html#toc_lt



littlejohn74 said:


> I've not seen any evidence from any of the links that would state otherwise.
> I'm not sure if "rejecting" blind tests would be a fair comment.
> I just find it difficult to draw definitive conclusions from experimental results where the details and methodology has not been made available. Or published in the same article.


Here you go. An excellent discussion one methodology used, giving you a chance to pick one apart.

http://www.bostonaudiosociety.org/bas_speaker/abx_testing2.htm

The classic study that was published in Stereo Review many years ago included all the raw data and statistical analysis. We used that as a class study. I wish I had not lost my copy.

An indictment would be if ABX / blind tests always produce null results. They don't.

http://idc1966.blogspot.com/2011/12/study-of-audiophile-blind-comparison.html

http://home.provide.net/~djcarlst/abx_caps.htm


----------



## TheHammer

vidiot33 said:


> It should not come as a surprise that people hear differently. After all, sense of taste is all over the map. Some people love hot spicy food; to me, it's just overpowering and painful. Some love the sound of horns, e.g., Klipsch, while others (including me) will run for the exits. If variability exists in other senses, why not in hearing?


I think you might be confusing the way people hear (or taste, or see) with their preferences - likes and dislikes?

Horns produce sound differently than a dome, electrostatic, or a folded tweeter. They do sound different. Some people prefer one vs. another.


----------



## Krelldog

vidiot33 said:


> I would agree with your comments about vision. You don't have huge debates over what looks good and there is at least general agreement on the part of videophiles that THX standards are a good thing. I'd love to see studies done that quantify this, but I'm not aware of any pending research. *I doubt we'll ever see a set of standards for what sounds good that the majority of audiophiles will sign on to*. I would guess that hearing would come after sense of taste for variability, but it's just a guess.



That's a fact, this endless debate about amps will continue until the next ice age. 


My friend, who has only been in the hobby for 6 years, followed all my advice except for the most important. He soundproofed and treated his room, bought a kuro plasma, Krell stereo amplifier, rotel amps to power his rears and center channel, a great subwoofer, cables, etc... etc...etc. Almost done....just needed some quality speakers to come full circle...

But he dogged my strong suggestion to buy high performance speakers, and selected his own to surprise me......a presumptuous decision on his part. ( used for 50% music, 50% blu's ). _ ( Once he upgraded the mains, the difference was night and day, all is good now.....the balance has been restored....and for not much more $ either )_
So all things being equal, ( and in my subjective *opinion* ), the speaker set is the most important piece of your system. :whistling:

Have a Happy Thanksgiving fellas! Enjoy!


----------



## littlejohn74

TheHammer said:


> Actually, I don't. Statistics are mathematics. Arguing against them is akin to arguing that 3+3 does not equal 6.
> 
> No it's not like 3+3=6.. That would be basic arithmetic.
> Statistics is the study of the collection, analysis, interpretation, presentation, and organization of data. And the point that you've missed is the the collection of data can me easily manipulated so that when analysed, it can be interpreted in a manner that fits a particular theory
> 
> http://en.wikipedia.org/wiki/Student's_t-test
> 
> The controversy usually arises as to what is statistically significant. This can be an issue when the result is close to the threshold.
> 
> http://en.wikipedia.org/wiki/Statistical_significance
> 
> Many get a bad impression of statistics because of polls (especially political) where a small difference in the wording and change the result. Other times, people confuse statistics with forecasting which has taken on increased controversy with the global warming debate. Statistics of the type that are used in listening tests does not forecast.
> 
> Or people who use statistics as proof of cause and effect - which is a mistaken conclusion, not an indictment of statistics as a science.
> 
> 
> 
> I don't see any evidence to support your statement. Please provide some.
> I'm not sure I follow.. I don't think I made any claims to anything.. Other than none of the articles I've read about ABX testing and amps appeared to be scientific in their methodology.
> 
> Many (but I am sure not all) ABX testing has been done under controlled conditions that are 'scientific' in their methodology. No pole driving was done nearby.
> None of the articles that people link to have shown this to be the case. The pole driving was just a stretch of the imagination to make point.
> 
> In order to be an accepted study, it must be published in peer reviewed publication. Then others must be able to duplicate the results. Research generally falls apart when others are unable to obtain the same results. ABX testing with amplifiers has been reproduced repeatedly, so it stands up to scientific scrutiny.
> 
> There are many different studies available on the Internet, if you want to read them.
> Here are a few scientific articles:
> 
> http://people.xiph.org/~xiphmont/demo/neil-young.html#toc_lt
> 
> 
> 
> Here you go. An excellent discussion one methodology used, giving you a chance to pick one apart.
> 
> http://www.bostonaudiosociety.org/bas_speaker/abx_testing2.htm
> 
> The classic study that was published in Stereo Review many years ago included all the raw data and statistical analysis. We used that as a class study. I wish I had not lost my copy.
> 
> I'm sorry.. I must have missed something.. I got that the article was about ABX testing and digital recordings. But I didn't see anything relevant to the topic at hand which is "Can we really hear a difference between amps?"
> 
> An indictment would be if ABX / blind tests always produce null results. They don't.
> 
> Sorry.. I think you've misinterpreted some of my comments. I've never said that ABX testing was invalid.
> As previously stated, comments relates to the uncertainty of ABX testing in the article relating to Amps. As there isn't enough detail in to determine the scientific nature and validity.
> 
> http://idc1966.blogspot.com/2011/12/study-of-audiophile-blind-comparison.html
> 
> http://home.provide.net/~djcarlst/abx_caps.htm


comments in red.
It would appear you've spent a fair amount of time to construct your response which is very much appreciated. But I think you've taken some of the comments I've made and gone off on a bit of a tangent.
Let me be clear here.. I'm not debating the validity of ABX testing. I am merely questioning the testing methodology used in links given regarding ABX testing relating specifically to the topic at hand which which is "Can we really hear a difference between amps?"


----------



## AudiocRaver

I think you have both made your points eloquently and completely, and will clearly never agree on the topic. If you have something new to present, please do, Otherwise, time to move on.


----------



## TheHammer

littlejohn74 said:


> comments in red. It would appear you've spent a fair amount of time to construct your response which is very much appreciated. But I think you've taken some of the comments I've made and gone off on a bit of a tangent. Let me be clear here.. I'm not debating the validity of ABX testing. I am merely questioning the testing methodology used in links given regarding ABX testing relating specifically to the topic at hand which which is "Can we really hear a difference between amps?"
> 
> Actually, I don't. Statistics are mathematics. Arguing against them is akin to arguing that 3+3 does not equal 6.
> 
> No it's not like 3+3=6.. That would be basic arithmetic.
> Statistics is the study of the collection, analysis, interpretation, presentation, and organization of data. And the point that you've missed is the the collection of data can me easily manipulated so that when analysed, it can be interpreted in a manner that fits a particular theory


If your comments are that the design of the test could be invalid, I agree with you. It is always possible to establish any test or test methodology that is invalid. One of my criticisms of ABX testing is that there are not positive nor negative controls. The closest we have to controls is that some tests produce positive results. If no ABX tests produced results, then that would be a condemnation of ABX in general.

Your definition of statistics is generally accepted. Please note that collecting the data is separate from designing and performing the test.

Statistics are the tool to analyze the data. It is impossible for two statisticians to look at the same data and calculate different conclusions (other than setting different thresholds for the null). The statistics do not lie, which was your original comment about the science of statistics.


----------



## TheHammer

AudiocRaver said:


> I think you have both made your points eloquently and completely, and will clearly never agree on the topic. If you have something new to present, please do, Otherwise, time to move on.


Yes, we have gotten repetitive. Unfortunately. Sorry for the taking up of space.

The title of this topic is "Can we really hear a difference between amps?"

It seems there are two groups, at least:

1) Yes. By careful listening, amps can and do sound different.

2) No. Placebo effect and double-blind / ABX testing is evidence that we cannot.

There could be a third group that I guess could loosely be defined as?: 

3) Maybe, but it is subtle. Speakers and room interaction (or something else) are more important.

To discuss this topic, we must address 'the elephant in the room', double-blind / ABX testing. Is there any other way to approach this issue? 

Unfortunately, as littlejohn74 and I have shown, it is difficult to discuss and make any progress. If we are unable to discuss double-blind / ABX testing, does this thread serve any purpose?


----------



## AudiocRaver

Might I suggest a thread on ABX testing, its validity, how to do it properly, things like that. There are a number of us interested in the topic. And in degrees of difficulty, for instance how to do it well without having to get into all of the steps and documentation and peer review and all needed for a scientifically valid conclusion. Granted it has its need and place, but a lot can be accomplished without carrying it to that degree. Just a few thoughts.


----------



## macromicroman

I would agree that double-blind testing is the only real test. Of course all other variables such as the room, number of people in the room, speakers and other equipment would have to be the same. Never change more than one variable at a time while testing anything. 

I also think that a significant number (people familiar with statistical testing could tell us this number) of people would have to be tested to get the correct answer. Testing only a small number would probably bias the results since some already have made up their minds one way or the other even before testing.

I believe as long as both amps are well made and have about the same power, most people will not be able to tell much of a difference.

I agree that the speakers chosen for the system will make thee greatest difference in the sound. Get the best speakers you can afford first then choose the amps and pre-amps.


----------



## Gregr

First off, thank you for your thoughts. I love it that this topic discussion never seems to end..., as it should never end. 

I agree with all of your ideas - beginning with the speaker. With a great set of (2,4,6,8 & subs??) speakers any well made amp with plenty of clean power can be adjusted to achieve a sound quality anyone could have imagined. I would only add that testing Class A and/or B tube amps (single ended or push pull topo') although may be especially satisfying comparing with a Class D and even A/B class it would be especially easy to identify which is which, even though both could be especially pleasing/satisfying when adjusted to its highest potential. Although the more popular A/B type amps compared with Class D (digital) would IMHO be a sound of very similar quality and adjustable to produce a very dynamic and satisfying sound. I don't know anything about G nor H Class amps except they are variations of the A/B type amps and are meant to minimize/overcome some of the some of the issues with A/B amplification. 

One more thought on sound amplification is the Damping Factor (DF) when speaker and amp are impedance matched the amps ability or need to control speaker excursion - that is as the amplified sound ends the speaker excursion is damped to 0 motion/moment. I don't even know where to begin except to say I was always told (oh so many years ago) to look for an amp with a DF of around 200. Today IMHO because the quality of electronic parts have such low variation measurements (as low as 2% and I haven't checked in awhile) the need for Neg Feedback to control distortion is reduced in tube and solid state amps. Today I.m seeing DF's of 40 like with NAD amps and even lower etc etc. 

Not to mention older tube amps were of such low power 15 watts was considered sufficient, the ability to control speaker excursion sub 100hz was impossible..., even with a very expensive 60W tube amp (especially Class A) the need to turn the power/volume up to realize low Hz numbers increases THD making it easy to detect which Class amplifier you were listening to.

Just a few thoughts - now on to the double blind placebo controlled testing..., well I don't believe anyone wants to hear about my thoughts on that. 

Happy Listening and Best Regards

Greg


----------



## Gregr

Oh, one more thought, lol - 

I wanted to suggest that any scientific comparison of amps and/or speakers must include the music of The Preservation Hall Jazz Band, but especially the one number titled "That's it" recorded live on Jimmy Fallon 13'. Even if you don't like brass bands this cut will blow your mind. Turn up the bass for that tuba duet and adjust for the snare drum ring and perfectly tuned tom-toms and floor toms - I don't know how this drummer holds the beat so fast and steady thru the whole number. Now the trumpet playing is as good as I could ever dream of and never be able to play..., for this trumpet number you better ave your socks pulled up tight and trousers bloused because he's gonna try to knock your socks off (best trumpet rendition is on YouTube under Jimmy Fallon 13' - Pres Hall Jazz Band). But here is where you will find a real test of amp and speaker dynamic - the band is amazing to me but the part I like best is when the band does a slight refrain and the trombone player does this dark and dirty blat-a-blat-blat-blat raspy grunge that will truly test the metal of any system.

This band is doing all they can or need to do to bring back/continue that NOLA Jazz Band sound. Yeah Man, the Preservation Hall Jazz Band is at the top of Jazz Band music. Their music isn't the wild Mingus style of jazz this music is tight and melodic and does things to your soul..., take a minute and listen but remember, hold onto your hat and socks cause they will take you for a ride, this is real music, you know the type of music that is so well conceived that it doesn't matter if its classic, or flamenco or folk - it grabs you and takes you to places sometimes we forget to remember, we get so caught up in life and living.

Edit: I cannot find the recording of the Live JFallon Show take..., looks like I'll have to buy it or pay to sign up for one of the sights that have it e.g. The Jimmy Fallon Show etc etc. 

Happy Listening and Best Regards
Greg


----------



## Savjac

Hi There



Gregr said:


> I agree with all of your ideas - beginning with the speaker. With a great set of (2,4,6,8 & subs??) speakers any well made amp with plenty of clean power can be adjusted to achieve a sound quality anyone could have imagined.
> 
> Hi Gregr
> May I ask what you mean by well made amp with plenty of clean power "Adjusted" to achieve a sound quality anyone could have imagined ??? So a well made Yamaha receiver of the 1980's - insert definition of clean power here - could be adjusted to achieve the sound quality of a new Levinson beast ? Is that what I am getting ? How would one adjust either unit ??
> 
> Just a few thoughts - now on to the double blind placebo controlled testing..., well I don't believe anyone wants to hear about my thoughts on that.
> 
> Does not work, never has, or there would be at least some differing results. Double blind aids in masking any meaningful differences. This may be why double blind was used in firing squads or hangings, you can never see what's coming,
> 
> Happy Listening and Best Regards
> 
> Greg


----------



## Tonto

Who's your buddy!
If this is not the one, I did a little deeper.


----------



## Gregr

Yeah - even if your in a bad space..., you gotta get something outa' that.

Ya know I got so caught up in writing I forgot to notice - the drummer only uses the single floor-tom and kick bass - he still gets my vote.

FYI - the KEXP session is amazing music to my ears but there is one better IMHO it is the Jimmy Fallon Showing. You'll know it when you see the-or-an audience on stage with the PHJB and the dance floor is filled with professional break and popping dancers. The trumpet player does not miss a note or a beat. But it seems unless you subscribe to JF site and recording medium playback etc etc 

Happy Listening and Best Regards


----------



## Gregr

Hi Jack,
Glad to see you and Tonto are still carrying the torch for humanity, music and theater. In these next few lines if I say anything that sounds off color or crass..., don't believe it, Please. I too, like most who like to write/talk and carry on about all of the above and as much as I attempt to write clearly with ample detail there are times when I fail.

When I wrote about clean power: I was imagining a clean circuit beginingwhere my 220v line seperates from a transfer station and traveles down to my house then is split through at the breaker box and routed through the house to a dedicated Audio system outlet and video system outlet. I'll just add - I'd love to try one of PS Audio' regeneration power stations for audio and video but for now my Monster HTS 3600 MKII will have to do...., and I'm not complaining. Next, paying close attention to cable routing/grounding issues minimizing electromagnetic field interactions (which I have not done to this day - maybe that's my first invention). I do use double shielded power cables, interconnects and a large ferrite at the speaker end of my Kimber Kables. Next clean/uninterrupted power through the speaker crossover and out to the voice coil windings.
I would add IMHO, I take every opportunity to buy the purest copper cables of highest electrical integrity - meaning all of the cables I use have an average resistance of 7-10 Ohms fer Kilometer.

As for the Double-Blind Placebo controlled study - I, you or any single individual can perform one - keeping in mind to watch for "first bias" "attitudinal bias" or simple prejudice e.g. transference/counter-transference's of personal nature and the desire to please.... However the real scientific study does not end here. Next is to design a research question/with questionnaire (containing only numerical values) for statistical analysis - after that it is endless listening. Two hours per day I believe would be minimal, thereby allowing the cabling and electronics to fully energize and function at its peak. Oh yes you can accomplish the same using a group of people as well. Next, for a more reliable correlational "solution for P" the higher the number of trials must be achieved. 

Its a monumental task ..., but it can be done. Then, this is where science really begins - because if you write the scientific question and use 10 numerical variables and repeat the test for seven days..., one day somebody will use 20 variables and study for 14 days and if this most recent study seems to validate your study you can begin the simple task of graphing each study "solution for P" and with each increase in variable and study length you should find each solution plot a straight line on a graph. Otherwise there may be an error in the study question or variable or the DBPC study perimeters.
Sounds like fun to me... not

sorry I didn't proof read - I wish I had, but you can see what is generally required -its late

Happy Listening and Best Regards


----------



## chashint

LOL.
When this thread gets the tires kicked you just never know what kind of "new" information will get posted.
Hopefully the most recent responders here have also found the amplifier comparison thread that was posted a month or so ago.


----------



## Lumen

I'm still looking :sneeky:


----------



## asere

Wow! Looking at the poll it looks like its toe to toe.


----------



## Savjac

Gregr said:


> Hi Jack,
> Glad to see you and Tonto are still carrying the torch for humanity, music and theater. In these next few lines if I say anything that sounds off color or crass..., don't believe it, Please. I too, like most who like to write/talk and carry on about all of the above and as much as I attempt to write clearly with ample detail there are times when I fail.
> 
> When I wrote about clean power: I was imagining a clean circuit beginingwhere my 220v line seperates from a transfer station and traveles down to my house then is split through at the breaker box and routed through the house to a dedicated Audio system outlet and video system outlet. I'll just add - I'd love to try one of PS Audio' regeneration power stations for audio and video but for now my Monster HTS 3600 MKII will have to do...., and I'm not complaining. Next, paying close attention to cable routing/grounding issues minimizing electromagnetic field interactions (which I have not done to this day - maybe that's my first invention). I do use double shielded power cables, interconnects and a large ferrite at the speaker end of my Kimber Kables. Next clean/uninterrupted power through the speaker crossover and out to the voice coil windings.
> I would add IMHO, I take every opportunity to buy the purest copper cables of highest electrical integrity - meaning all of the cables I use have an average resistance of 7-10 Ohms fer Kilometer.
> 
> As for the Double-Blind Placebo controlled study - I, you or any single individual can perform one - keeping in mind to watch for "first bias" "attitudinal bias" or simple prejudice e.g. transference/counter-transference's of personal nature and the desire to please.... However the real scientific study does not end here. Next is to design a research question/with questionnaire (containing only numerical values) for statistical analysis - after that it is endless listening. Two hours per day I believe would be minimal, thereby allowing the cabling and electronics to fully energize and function at its peak. Oh yes you can accomplish the same using a group of people as well. Next, for a more reliable correlational "solution for P" the higher the number of trials must be achieved.
> 
> Its a monumental task ..., but it can be done. Then, this is where science really begins - because if you write the scientific question and use 10 numerical variables and repeat the test for seven days..., one day somebody will use 20 variables and study for 14 days and if this most recent study seems to validate your study you can begin the simple task of graphing each study "solution for P" and with each increase in variable and study length you should find each solution plot a straight line on a graph. Otherwise there may be an error in the study question or variable or the DBPC study perimeters.
> Sounds like fun to me... not
> 
> sorry I didn't proof read - I wish I had, but you can see what is generally required -its late
> 
> Happy Listening and Best Regards


Hi Greg and Thank You for your post, it makes me smile that someone is willing to debate sensibly on this tense matter. Have you noticed that the poll goes up or down by a few persons depending on which audio nut posted last, be it positive or negative ?? Cool.

I also want to thank you for thinking Tonto and I are keeping up the challenge so to speak when in fact there are hundreds of folks on either side of the fence that have just given up LOL, they can only take so much. 

To your first point, I do understand, we all have that issue to some extent. Like you I do not have a regeneration station but merely a large power filter most things plug into so from that point most of us are equal. Getting a good clean amount of electricity into the equipment is a grand idea, and that means all the equipment, however, some items have built in filters and what have you right in the power supply architecture. My Emotiva amps do not recommend that they be plugged into anything but the wall as they draw a significant amount of current and have those filters built in. I am not sure it matters one way or the other as I do my testing with the amps plugged into the wall. All other equipment is plugged into the power supply filter thingie. So with the clean power not always available but lets agree that all amps being tested are plugged into the same source, we should have theoretically an even base to start with. No advantages to a receiver or a monster current user. 

Ok on to point two. I personally have no desire to enter into a blind test or as you say placebo test as they have been done so many times and with a very high percentage of reaching the same conclusion. No reason to go over them any more as to me they appear more methodical then scientific. I believe that there are no tests presently available that can fully recreate what we as individual humans perceive in our ear brain interface. BlueLou reminded me this weekend that there has been a panel conducted by Harmon Labs that uses numerous personnel and equipment to try and work out a generally perceived and subjective finding of a good system to the most of the masses, however, even with the greatest of mathematical equations, this can only tell us what tends to sound good. The trouble further down the line is that as humans we do not hear the same and there are no proper measurements for what we as individuals cherish in our sound reproduction. I dont like nasty highs but someone who is maybe loosing their hearing in that range of frequency would disagree and say, maybe those highs I find nasty are the pudding in his or her cake. You know the one mans ceiling is another mans floor. Further, there are no tests for sound staging in a music system. How deep and wide, high or low is a human thing born of tens of thousands of years of evolution if you believe in that sort of thing. Lastly, what is important to an individual listener, dynamics, delicacy, slam, bass, midrange, treble, female vocals, male vocals, orchesta music, rock, pop, jazz and on and on. Some folks love the ability to move walls with bottom end etc. 

In my opinion the above is WHY amps sound different from one another and when one combines their sonic preferences with their pocket books, voila, we get enjoyment. If all amps sounded the same, there would be no reason to have so many types and brands. It would be scientifically inconceivable to think that the design, implementation and quality of the components within an amplifier have no affect. It seems that one cannot ask the question, "Do All Amplifiers Sound The Same" without a good number of conditional variances being placed into the mix. An Amplifier amplifies and that is where we need to hang our hats. If too many conditions are applied than the question must be changed. By adding conditions, we are forcing all of the amps into a similar place where good ones and less than good ones may be the same. That imo is not proper. And yes, an AVR has an ampifier in it and as such works as an amp and preamp all in one box, where as separate basic amps need an outside preamp. Integrated amps really work well too without all of the other electricity sucking options most AVRs have. 

As such, I feel that a middle of the road AVR and an outstanding Basic amp/preamp combination need to be tested equally. If any version does not work then it is not acceptable and by that I mean if it does not sound good or if if it cannot make music for any reason, they ohh ohhh it needs to go.

Lastly I think more folks probably need to hear as much live music as possible to be able to detect all of the nuances made above. Without that basic knowledge, there can be no room for a proper investigation, imo of course. lddude: This evolution of discovery takes a great deal of time....on occasion and takes patience.


----------



## NBPk402

Not sure how to vote... I think there are differences in amps whether it is by design or quality of parts. How much of a difference? As soon as Audyssey or Dirac is brought into the equation though I think it gets real hard to hear any difference at all.


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## Gregr

Hi Jack - Your right there are many people here who do keep keep this site alive and down to earth. I started looking for the amp discussion yesterday and was real happy to see the advertising is still well out of the way. Lots of great topics as usual including this one "Can we HEAR the difference"

Thank you for your thoughtful experienced and considered thoughts. I have a feeling You and I and probably 80% of the people voting know already that this discussion probably will never be resolved to an agreeable solution, that is at 100%, could it ever be 100% we are discussing humans and individual senses. You know when Sonnie first refreshed this question I felt I knew his reason, its a great question. I only wish there was an real answer but the discussion "ahhh, the discussion" it really makes me wonder. 

However if you were to hear from a statistician and audiophile he/she might declare from oh but of course to within a degree of certainty... and so on. But what about an artist - even Monet might declare his frustration with the public, "people are so fickle..., there is no pleasing them."(my imagination not Monet' words).

I did start thinking of a simple questionnaire (in case somebody did ask)..., but the further along I got I stopped quick with a thought - what if after years of statistical analysis it is discovered we've been asking the wrong question. What if the research question is actually "___________". What if hearing is like color blindness and every other human anomaly and everybody listens and hears differently. 

Consider for a moment a survey questionnaire of this type:
Question 1. Did you hear the Cymbals
Answer 1. Not really, no
2. a little/from time to time
3. Yes clearly

Question 2. Did your hear the keyboards - Piano/organ 
Answer 2.

...same answers as above.

Then I thought well wait a minute, I can't listen for all of the instruments and answer these questions at the same time (continue with me for another moment) - I don't hear music like that... the best I can do is develop a ghostly quiet background so that well recorded music has every opp to bloom and send out every tenuous tendril of sound that sparkles and shimmers and continue endlessly in my mind. You know what I mean. I know you all do.

I'm getting older and the I know my upper listening ability is fading. I believe this is why I am so obsessed with the sound of the cymbals in the music I listen to. From the ring of the cymbal crown and gong sound of the crash cymbals and the sizzle of the riveted ride cymbals and one day..., only when I stop to wonder and remember will I truly miss anything at all. 

Because I believe I see (for myself at least) I do listen for the cymbals but I also listen for the lead guitar and I listen for the keyboards etc etc etc etc BUT what I hear is everything. I hear individual instruments, but what is music? Its all of the above and the harmonies and all those dancing tendrils of sound and the space between the notes "ahhh Sigmund, its the spaces between the notes that thrill to the core of my being" That ghostly quiet that speaks to me..., OK I might have over done this a bit but its been one of those days.

If when I am finally very old (whatever that means) and all I can hear for sound is the sound of Mr Wailing Jennings old raspy voice over a little slide guitar pickin' that'al be just fine with me too. 

I don't wonder why we all get so excited about this topic... I feel like I'm forgetting to fully answer your response Jack but I'll have to check back to be sure I have treated you with the utmost respect I do believe you've earned and deserve. 

Happy Listening and Best Regards


----------



## lcaillo

Well, the question is never going to have a one size fits all answer. But what we can say is that it is very hard to identify differences reliably among decent quality amps. The methodology of testing is quite difficult and many oversimplify the concept of AB or ABX testing. 

The conclusion that I come to after more than 35 years in the business and listening to more different products than most people, and more live performance than most, is that differences in amps are rarely significant. However, I do not discount the possibility that they exist and the only fair way to address the question is to do our best to identify differences if the do exist. I go into comparisons with the assumption that I will be able to hear differences and try to document what they are. If they can be identified consistently, I think we can agree that they are real. I have yet to be statistically successful in identifying differences. I have had some consistency across blind comparisons, but not enough to reach statistical significance. Maybe with more trials and more control of variables like distractions and listening time....


----------



## Gregr

Yep,
I think I understand in essence what is happening. This is not a judgement ..., but whats happening (i think i can see) I'm just stirring the pot one more time and what'ta you know "nothing new here"
I wonder if a statistician would ever take on this task he/she would need to have a high appreciation of music and sound reproduction. 

Another concern/issue I think I see is "the industry" is moving too fast. I mean how much time do you get to spend with comparing the same any two amps. One weekend and its on to the next shinny and newest iteration. The basic electronics "Pre to Power" haven't changed much except the sound gets processed differently from 10trs ago.

If I ever come up with a survey questionnaire I'll post as a new post open to discussion and critique...

Just Thinkin':An old friend has a pair of 50's vintage "Altec Lansing Voice Of The Theater" speakers and at least 20 to 50 Pre/Power amps to choose from, both new and vintage, but the sound.... The sound you feel is cavernous while filling a 20x20' room and is awe inspiring. You can actually see many notes traveling across the cone excursions. 

Happy Listening and Best Regards
Greg


----------



## Gregr

I love this video - I find no difficulty accepting Mr. Krueger' descriptions of electronic phenomena in minutia and even as he describes the minds ability to steer itself to into convincing oneself of what was intended/expected to hear. Only a few times did I get the sense Mr Krueger forgets that even his descriptions lean toward subjective bias. Do not misunderstand me I find this info truly inspired and each point valid in each seperate domain(subjective audio register). I simply enjoy music when I hear what I expect and/or want to hear "that's the best for me" - my room treatments are the coat rack, furniture and clutter except for the louvered room divider that in effect squares the room. I work with toe in and speaker distances along with Audyssey leveling. One day I may apply baffling to the front wall but I'm liking the sound-stage I hear and I'm afraid I'll then want bigger speakers. Blah, Blah, Blah Just consider all the sound reflections even at Carnegie Hall or the Orpheum Theater. I remember the Kooper, Bloomfield "Supper Session" at the Boston Gardens in the 60's (it doubled as an ice arena) like a theater in the round the music was everywhere but the volume and music at center stage blew me away. I don't believe I would like a dead quiet room LOL - but if I can quiet my mind from all of the useless chatter and truly hear what is in front of me..., who knows???? As usual I could be persuaded to change my mind. 

Happy listening and Best Regards
Greg


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## Gregr

Dogs will love ya and treat you like your the greatest every time you walk into the room and you do have a point to coonsider. 

I love it....
Greg


----------



## Lumen

Gregr said:


> Dogs will love ya and treat you like your the greatest every time you walk into the room....


I resemble that remark 

Sent from my iPad using HTShack


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## willis7469

BlueRockinLou said:


> I resemble that remark  Sent from my iPad using HTShack


 one of my favorite lines!


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## Savjac

The dogs do love Blue Lou, yep indeed.
I think Leonard has it right in that we will never reach a consensus in out opinions and I really dont want to try to influence anyone. Anything I type seems to come back as me trying to put a blanket of my beliefs onto someone else...and....others opinions oft times feel like a blanket of beliefs on me. This has to be so much easier when we come to accept that maybe we can both be right. I have mine and will live by them and the other fine group of gents seem to be happy as well. So what the , lets listen in a way that makes us happy and maybe raise a bit of goose bumps on our collective skins. 
I would even cheer for a tear or two. Yeah baby !!!


----------



## chashint

Savjac said:


> The dogs do love Blue Lou, yep indeed. I think Leonard has it right in that we will never reach a consensus in out opinions and I really dont want to try to influence anyone. Anything I type seems to come back as me trying to put a blanket of my beliefs onto someone else...and....others opinions oft times feel like a blanket of beliefs on me. This has to be so much easier when we come to accept that maybe we can both be right. I have mine and will live by them and the other fine group of gents seem to be happy as well. So what the , lets listen in a way that makes us happy and maybe raise a bit of goose bumps on our collective skins. I would even cheer for a tear or two. Yeah baby !!!


Well said.


----------



## AudiocRaver

In the process of completing a recent speaker review, I had an interesting experience relating to this discussion. There were three amps used to drive the speakers in question - 94 dB efficient, so they did not need huge amounts of power to play at a decent volume. There was a 15 w / channel solid state amp, a pair 300 W / channel differential class-A solid state monoblocks, and a pair of 8 W / channel SET tube amps. A few observations:

I never heard hard clipping from the 15 W / channel solid state amp, but there was a point beyond which I wanted to hold back on the volume, and a sense of strain or tension if pushing the volume further. Presumably, the ear starts to hear an occasional small "clip" or the mere onset of clipping and reports it as that "tension" in the sound. While driven "clean," there was nothing distinctive about their sound.
The 300 W / channel monoblocks had such energy reserves that they felt like you could bring down the house and never hear distortion. A point for "can't hear a difference...???" Maybe, but there was an emphasis in the mid-bass that was totally unexpected and easy to identify. I mentioned it to my host and he said he had noticed it, had taken measurements, and the measurements showed no difference from other solid state amps. With no measurements of my own and no further data, all I can say is there was something about amp/speaker interaction that was audible and it was definitely NOT distortion. So, where in this discussion does that one fit?
The 8 W / channel SET tube amp had what I can only describe as a softened attack on the bass, again clearly audible. This can be explained by the higher source impedance of the tube amp and the lower damping factor, affecting the degree of control the amp has on driver movement, mainly the woofer. So this might be a data point for the side saying an amp can sound different because of a different design, another case of amp/speaker interaction causing a different sound. This could probably be shown with careful measurements of the right type. These amps were not pushed hard at all, so it was not a distortion / nonlinearity issue.

So, three amps, three different sounds. The small solid state amp with its clean sound when not driven to the beginnings of distortion, the big monoblocks with an apparent boost of mid-bass - unexplained, and the tube amps with no apparent mid bass boost but with softened bass attack due to lower damping factor. All this was totally unexpected to me. I was not looking for or expecting to hear any difference at all or even thinking about it, they just jumped out at me quite obviously and were confirmed by other listeners.


----------



## Savjac

Excellent post Craver, I am glad you tried a nice group of amps that could not be more different from one another. SS and Tube amplifiers work differently when connected to a loudspeaker in that SS tends to drive the speaker and accepts no feedback while a tube amp tends to drive the loudspeaker but does accept some feedback thus allowing the amp and speaker to sort of speak to each other.

I dont think one is better than the other when it comes to most situations, however the low power set will not work well with most speakers not intended to be driven by the flea watt brothers. I have a 30 wpc tube amp that does not really sound all that "Tubey" if you will but even at 30 wpc, it has limitations. 

Lastly, I wonder if there will ever be a definitive answer as to the proper amount of damping factor needed to control a loudspeaker. Most experts seem to say anything above 20 is good and should work fine. Crown seems to say 1000 might be really good and the class D amps tend to all have some serious damping factor but have not thus far been well received. This is a great post up.


----------



## frustrum

(A little thread necro to the thread that brought me here, in the market for some new separates to drive my Martin Logans.)

Hello everyone, :wave:

I found this thread pretty amazing and eye-opening. I found myself wishing the "no difference between amps" camp had a resource like the following:

- A list of "good enough" amps that fit the criteria of this thread. lddude: Rather than sites with hyperbolic effusive descriptions of amp sound -- a thumbs up/down for given speaker drive should be sufficient.
- And/or a guide on how to do "good enough" testing on a given amp so someone else could carry the above mantle.

I don't have the EE background it appears many in this thread have so I was lost a few times when people were checking amps with voltage meters for given impedance, etc. I have "hard to drive" speakers and would like to be sure I get an amp that can drive them with great imaging and lots of air. :huh:

FWIW, I have always heard differences between amps -- but almost all of those impressions were from integrated amps or amps on low-end pre-amps... so it makes sense to me that the big difference would be in the pre rather than the amp proper.

Thanks in advance to anyone who could point me to a resource like I mention in the above.
For the curious I'm currently considering...

Krell Foundation pre-amp
Pass Labs amp for the fronts (MartinLogan Ascents). Hopefully would be better than my old dead sonographe? I did love that (cheap) amp.
No real thoughts for rear amp yet.


----------



## Flak

AudiocRaver said:


> In the process of completing a recent speaker review, I had an interesting experience relating to this discussion. There were three amps used to drive the speakers in question - 94 dB efficient, so they did not need huge amounts of power to play at a decent volume. There was a 15 w / channel solid state amp, a pair 300 W / channel differential class-A solid state monoblocks, and a pair of 8 W / channel SET tube amps. A few observations:
> 
> I never heard hard clipping from the 15 W / channel solid state amp, but there was a point beyond which I wanted to hold back on the volume, and a sense of strain or tension if pushing the volume further. Presumably, the ear starts to hear an occasional small "clip" or the mere onset of clipping and reports it as that "tension" in the sound. While driven "clean," there was nothing distinctive about their sound.
> The 300 W / channel monoblocks had such energy reserves that they felt like you could bring down the house and never hear distortion. A point for "can't hear a difference...???" Maybe, but there was an emphasis in the mid-bass that was totally unexpected and easy to identify. I mentioned it to my host and he said he had noticed it, had taken measurements, and the measurements showed no difference from other solid state amps. With no measurements of my own and no further data, all I can say is there was something about amp/speaker interaction that was audible and it was definitely NOT distortion. So, where in this discussion does that one fit?
> The 8 W / channel SET tube amp had what I can only describe as a softened attack on the bass, again clearly audible. This can be explained by the higher source impedance of the tube amp and the lower damping factor, affecting the degree of control the amp has on driver movement, mainly the woofer. So this might be a data point for the side saying an amp can sound different because of a different design, another case of amp/speaker interaction causing a different sound. This could probably be shown with careful measurements of the right type. These amps were not pushed hard at all, so it was not a distortion / nonlinearity issue.
> 
> So, three amps, three different sounds. The small solid state amp with its clean sound when not driven to the beginnings of distortion, the big monoblocks with an apparent boost of mid-bass - unexplained, and the tube amps with no apparent mid bass boost but with softened bass attack due to lower damping factor. All this was totally unexpected to me. I was not looking for or expecting to hear any difference at all or even thinking about it, they just jumped out at me quite obviously and were confirmed by other listeners.


Hi Audiocraver,
your posts are always interesting 

Do you have the opportunity to connect an oscilloscope during the playback with actual music material with a wide dynamic range and a real loudspeaker load?
I think that much more often then expected the amplifier may be clipping but for such short periods of time (milliseconds during the peaks) that the listener cannot recognize that as clipping... but the sound quality would nonetheless be different for trained listeners, what is your thought?

(may be there is truth in both camps 'cause in the real world we don't listen under controlled conditions and if we did we may have surprises from the behaviour of our amps...)

Thanks, Flavio


----------



## chashint

The HTS brain trust did an excellent amplifier evaluation get together.
The iPad is not letting me capture the link to the thread but a search for...

Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread 

Should find the discussion thread.

There was a lot of effort put into that evaluation and report, it is a good read.


----------



## Gregr

Here is the link Chase referred to: 2015 Amp Eval - 

http://www.hometheatershack.com/for...uation-event-reporting-discussion-thread.html

..., but first there are a few considerations to keep in mind as you search HTS. One is, although most HTS members admittedly have dedicated two channel audio setups in their "Home Theater (HT)" much of what I've read here @ HTS is about "HT" multi-channel listening. That does not mean the information and equipment testing, reviews, opinions presented herein can be or should be overlooked. 

Second, much of the testing and reviews deal with the newest and best multi channel AVR's, Pre/Pros, DAC's, Amps and Video equipment. 

Third, HTS is not a Hi-end Boutique "cost is no object" forum. 

That said - if you want to learn about the newest and best electronic A/V technology available in the market and how to setup a theater or two channel system that will give you goose-bumps every time you hit the power button..., keep reading, your getting close.

I am not saying your headed in the wrong direction with Krell and Pass Labs. I keep thinking a Krell Showcase is in my future or just start with the Krell Vanguard. I should..., before my hearing losses are noticeable to even me.

I'll just add - if your looking at the Pass Amp because (as advertised) it will handle "low impedance loads" and you believe your ML electrostatics are difficult to drive for that reason..., stick around. There are and have been HTS members playing even music thru ML Electrostatics powered with Emotiva seperates and integrated elec's and I believe even Denon AVR's and the like all without issue given ample wattage. 

My simple observations are (some experience) most of the High Current including digital amplification Audio electronics in the 125-200watt range will reproduce a very satisfying reference level sound that will keep you on the edge of your seat or in the dream state - whichever you prefer. 

All that said - I'm thinking about the Krell Showcase even more seriously now.


----------



## AudiocRaver

frustrum said:


> (A little thread necro to the thread that brought me here, in the market for some new separates to drive my Martin Logans.)
> 
> Hello everyone, :wave:
> 
> I found this thread pretty amazing and eye-opening. I found myself wishing the "no difference between amps" camp had a resource like the following:
> 
> - A list of "good enough" amps that fit the criteria of this thread. lddude: Rather than sites with hyperbolic effusive descriptions of amp sound -- a thumbs up/down for given speaker drive should be sufficient.
> - And/or a guide on how to do "good enough" testing on a given amp so someone else could carry the above mantle.
> 
> I don't have the EE background it appears many in this thread have so I was lost a few times when people were checking amps with voltage meters for given impedance, etc. I have "hard to drive" speakers and would like to be sure I get an amp that can drive them with great imaging and lots of air. :huh:
> 
> FWIW, I have always heard differences between amps -- but almost all of those impressions were from integrated amps or amps on low-end pre-amps... so it makes sense to me that the big difference would be in the pre rather than the amp proper.
> 
> Thanks in advance to anyone who could point me to a resource like I mention in the above.
> For the curious I'm currently considering...
> 
> Krell Foundation pre-amp
> Pass Labs amp for the fronts (MartinLogan Ascents). Hopefully would be better than my old dead sonographe? I did love that (cheap) amp.
> No real thoughts for rear amp yet.


Your suggestion has merit. Finding

A torch bearer to compile the information you suggest
Agreement on the results
is the tricky part.

Sonnie Parker owns a pair of ML Electro-Motion ESL, their entry-level hybrid electrostatic model. He drives them with 2 channels of a Parasound Halo A31. I have listened to them at near blistering volumes and the combination sounds amazing.


----------



## AudiocRaver

Gregr:

Love your signature line:

"We believe everything we tell ourselves..., don't we??"

My answer (FWIW): Yes, until we start to question what we have been believing... "Do I really believe that? Am I really hearing that?"


----------



## Gregr

AudiocRaver said:


> Gregr:
> 
> Love your signature line:
> 
> "We believe everything we tell ourselves..., don't we??"
> 
> My answer (FWIW): Yes, until we start to question what we have been believing... "Do I really believe that? Am I really hearing that?"


Exactly - I used to say we stumble upon our best lessons in life..., then proceed after achieving a reasonable sense of equilibrium. In effect, convincing ourselves of our unique intellectual/expert (expert in the sense of our unique experience/not all-knowing) nature. Otherwise, personal schema breaks down and neurosis sets in..., or worse. Maybe a good reason why we defend our positions so adamantly - like life depended on it for some...
I like a bumper sticker I saw once "question authority" and I sort of re-purposed it for my benefit, "Question Reality" then I stumbled upon the question: We believe everything we tell ourselves... .

You know, as do I, electricity can be defined mathematically - but what is the energy that fills the void between and creates the 3D construct of pos/neg, where does that energy come from..., its just there and we define it from the position of observable phenomena, right? Science is still discovering dimensions of lightning that redefines the way science views the world e.g. sprites and ionic expansion etc. What of quantum science and the prediction of higher and lower in-phase, energy levels or dimensions existing within our reality/dimension..., no longer a hypothesis this is a working theorem in the quantum world.

I don't claim to have a golden ear and at 65yrs after listening to loud music most of my conscious life I've probably given up the opp to develop an educated ear, so I'm on the fence as to what the differences in sound in pre/pro/amp could be as described by others.

But try this simple experiment: take two lengths of speaker cable; one simple OFC lamp cord and another an MIT Shotgun or Kimber 8TC speaker cable (random selection). First, play music using your typical cables, then:

1. disconnect power source 
2. disconnect a single speaker cable (disconnect from the amp first)
3. connect (the speaker end of the cable first) any purported "better cable" of equal length in place of
the removed cable.

..., and listen. I'll bet for the first few minutes your head will tilt sideways. However, in time, I'll bet somehow the cables sound more and more similar. Like when children are born cross-eyed and after corrective surgery may view the world upside-down in one or both eyes, but eventually (usually) the mind re-inverts to a more useful upright and uniform vision. Or, did the amp/pre/pro equalize in response to electro-stasis tension or... ?

I sense we listen to elec sound and video reproduction in hopes of suspending disbelief even for just a moment and hopefully longer. As far as the "can we hear..." question, I'm not sure what the answer is or if there is a definitive answer. I am sure if 12 people are listening to music in the same room at the same time you'll get 12 different descriptions of what they heard (except when each of the 12 are very familiar with the expectations of others in the group). Sometimes I wonder if the question is "can people be trained to listen and hear reproduced sound critically". But then the question is how? Free-divers can train their bodies for deep-dives but what considerations would you choose for adjusting/max psychophysiology, bio-physiology, belief structures/expectations, recency effect and other forms of bias etc etc...

I should write a book, but not here.

Sorry to go on like this...

Best Regards and Happy listening


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## awood

Well guys, I'm in the pro-audio since early 1990 and the only thing I have to say is that "there is a big difference" between amps and I will put an example from my personal experience : Back in 1999, I won a contract to upgrade an auditorium sound system that has an EV 2 way active system 4 tops+4 subs all with QSC MX 3000 & 4000 amplifiers. So before moving to a new speaker system , I switched all amplifiers and tested with Lab-Gruppen FP series and the sound changed absolutely , so big was the difference in sound quality that I did an A/B comparison test with the same system : L with the original QSC amps & R with the Lab Gruppen and that's it and the difference was immediately noticed.
This is my personal experience and there's a big difference between amps, at least in the pro-audio field.

Cheers.

Alan


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## tonyvdb

Its very possible looking at the specifications of the QSC MX 3000/4000 that they may have been loaded up to much. Without knowing what model of the Lab-Gruppen amps its hard to say. If the Lab-Gruppens were able to handle the load better without distortion that can be a big change in sound.


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## AudiocRaver

Treading carefully, I have to admit that I have heard some differences as well. One pair of speakers that I reviewed a couple of years ago sounded markedly different depending on the amp in use. tube vs solid state, both amp pairs monoblocks. Damping factor interaction with speaker impedance might have been involved. Channel separation is rarely specified vs freq any more, and that is another area which could affect imaging at HF, causing a perceptible difference in "sound."


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## tonyvdb

I agree, I recently had to pull my Samson Servo 600 out to get fixed (one flakey channel) and used my QSC MX1500 for a few weeks and the sound was very warm compared to the Samson. The highs were more laid back (actually did not like it) and was glad to get the Samson back in. The QSC is 4 times the power output so I had to run the gains really low at about 20% so not sure if that had any impact on the sound.


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## Gregr

awood said:


> Well guys, I'm in the pro-audio since early 1990 and the only thing I have to say is that "there is a big difference" between amps and I will put an example from my personal experience : Back in 1999, I won a contract to upgrade an auditorium sound system that has an EV 2 way active system 4 tops+4 subs all with QSC MX 3000 & 4000 amplifiers. So before moving to a new speaker system , I switched all amplifiers and tested with Lab-Gruppen FP series and the sound changed absolutely , so big was the difference in sound quality that I did an A/B comparison test with the same system : L with the original QSC amps & R with the Lab Gruppen and that's it and the difference was immediately noticed.
> This is my personal experience and there's a big difference between amps, at least in the pro-audio field.
> 
> Cheers.
> 
> Alan


..., always a sensitive and potentially highly controversial topic, please do not feel offended by any comment I make. I am no expert on any Amp class type and/or amplified sound qualities. I am only trying to understand how there can be differences in reproduced sound.

Alan I wonder..., if a third party had set-up the new amps to reproduce sound similar to the amps being replaced (before your first listening) would the sound you first heard be as starkly different. 

But I wonder too did you replace an old Class A with a new Class AB and/or transistorized AB. I am learning that some of the newer transistor AB amps can get the cross-over distortions to nearly non-existent. Most amp designers and builders today are able to achieve and maintain low distortion levels in sound amplification for moderate dollar values etc etc 

I could be wrong but I believe the original question is, "can you hear a difference between two amps of similar design when each is set up to reproduce their best sound or a similar sound...?" Seems to me there was a $10,000 challenge. If anyone can hear a difference between a $1000 amp and a $10,000 (approx) amp of similar Class Type in a "Double Blind Placebo Controlled Study" when each amp is set-up to reproduce its best sound, all other variables being equal... :scratch:

You'll have to do the research on this if you want to reproduce the original experiment using newer equipment. But I'd love to watch and listen and contribute what I can. :innocent:

Alan I believe your statement was in response to your experience and I believe you did hear a difference but I believe one long standing question on this is... "why?"

Thanks for your comment - i love this question :surprise:


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## RTS100x5

I would have to say YES in general - but SO many factors in the chain affect the sound to a greater degree than the amps involved its almost a mute point > ie speakers-source-source recording etc etc

On that note - my new setup with BALANCED connections > Marantz 7702 > DDRC-88BM > Emotiva XPA7 has a much more discreet channel resolution than any unbalanced system Ive had .... The DDRC obviously has made a world of difference - especially in time alignment and phase response .. I am a true believer...


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## AudiocRaver

Going out even further on this limb that is already very fragile...

I wonder if many of the differences actually heard can be explained by:

amps operating in spec but...
attributes that are not specified, poorly specified, or spec is poorly understood
attributes that are more difficult to correlate directly to "listening experience" because of psychoacoustical interpretation factors involved


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## Savjac

AudiocRaver said:


> Going out even further on this limb that is already very fragile...
> 
> I wonder if many of the differences actually heard can be explained by:
> 
> amps operating in spec but...
> attributes that are not specified, poorly specified, or spec is poorly understood
> attributes that are more difficult to correlate directly to "listening experience" because of psychoacoustical interpretation factors involved


Fragile limb, I like that AC and may steal it at one time or another.

I am of the no all amps do not sound the same or maybe I should say that while different amps made by the same manufacturer might sound very similar amps made by a different manufacturer may sound significantly different. You may be right that amps may operate within its specs and yet not operate as one would hope may fall short.
If in the second post you mean amps that cheat on their specs, i.e., 100 wpc x 2 @6ohms vs 100 wpc x 2 @ 8 ohms or some dishonest variant thereof.
I am unsure what the third entry means, as such I look to your further enhancement of the statement.

I have three amplification systems in my main room, Denon, Emotiva and an integrated Tube amp from Dared. All three sound significantly different from each other when fed from the same dac to the same speakers using all of the same cabling. Denon is less powerful than the Emo but considerably more powerful than the Dared. The differences in sound between the two solid state amps is one of timbre and the integrated tube amp seems to have more solid bottom end and a much improved soundstage...I should add perceived. 

Like anything, maybe its in the power supplies, or any of the internal components, but when properly volume matched, well as close as I can get, all three sound different enough from one another to allow my to pick preferences. This is also true with the four dacs I have in house presently...but that is another discussion. :wink2:


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## AudiocRaver

A fr'instance:

Channel Separation gets worse as frequencies increase and is more an issue with a power amp or integrated amp than with a preamp, because of the current levels involved. Most manufacturers do not even specify this (Yamaha does). Poorer channel separation will affect imaging at high frequencies. It is conceivable that a difference in imaging could be heard between two amps, one with good channel separation and another with poorer channel separation, and there would be no explanation because that particular spec is under-emphasized these days. Both amps could be operating in their linear range (no clipping), and still "sound" different.


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## Oleson M.D.

Late to the discussion...but:

Until yesterday my answer would have been a resounding no. But with my new Klipsch RF-7 III's, there is a difference in sound between my two systems.

#1 - Dynaco PAS 3 Series II Tube Preamp & Sound Values Mosfet 32 Power Amp
#2 - Yamaha CX-A5200 A/V Preamp & Emotiva Power Amp

We can run both systems side-by-side, with a selector option so I can do direct A-B comparison.

System #1 has a much more liquid nature, with just a hint of warmth. Easy to listen to.

System #2 is more analytical, anti-septic in nature. Clear, concise. Non-colored.

For 2 channel stereo, the tube system is much better. For 7.2.2 surround sound movie tracks, the all solid state system wins hands down.

Yes, you really can hear a difference.


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## wantAvote

I have only two thoughts/questions..., 1. have you allowed time for your equipment to acclimate and adjust. Years ago it was believed system parts and pieces including speakers required extended time to break-in. Today's capacitors etc are not as finicky etc and an acclimation period is more often missing from conversations somehow but not necessarily any less required. 2. a psychological perceptual set theory e.g. after using curry in every main dish one is desensitized thereby requiring more of the stimulus curry in order to achieve past equivalent sensation. Also other taste sensations change or are altered in relation to the original taste of curry and with every iteration of change. 
I feel the curry analogy is a fair representation of how with equipment changes, sound changes for reasons described above but only briefly.
After some break-in time and after adjusting each sound system to achieve its best sound repro are the differences still apparent?
I love that this question rises to the surface from time to time. thanks


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## willis7469

Ime, tubes tend to sound warm, so I wouldn’t be surprised.


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## Oleson M.D.

The theater surround amps, 4 B&K, 2 Emotiva, all sound very neutral. B&K has a reputation for being "tube-like", but I do not think so. They are neutral, putting out whatever is delivered to them, in a manner that does not "color" the sound.

Same for my Emotiva's. Neutral. Period.

The RF-7's have about 50 hours break in time now. Just went to the theater, and did another direct A-B sound check.

Let me qualify this by saying I'm middle aged, with a long career of flying jet aircraft (noisy cockpit!), so my hearing is not what it was years ago (dang it!).

The difference between the two systems is very hard to notice. The volume levels are matched pretty close. Switching back and forth, between the tube system, and the Yamaha/B&K system, there might _(might)_ have been a very small difference. But then it may have also been what they call "expectation bias".

To know for sure, it would have to be performed as a double-blind listening test.


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## wantAvote

Expectations, they become obvious without warning and what then is the answer? How do we quantify what is mostly subjective to begin with..., the struggle is a strong inclination to believe everything we tell ourselves?

However objectively, are you loving, enjoying what you hear? If so isn't this the hope? I am approaching 70 and i still love a loud, clear and detailed soundstage. The sizzle of Zildjian cymbals...

You've got great pieces of kit. Sounds like the tubes in your Dynaco are adequate e.g. the warm and liquid descriptors are almost an expectation, these details are repeated so often. Your Yamaha on the other hand i would expect is lacking weight or body, though the sound is detailed and involving. 

However i believe most modern AVR's, pre/pro's and amp's can be improved, tweaked to fulfil hopes and expectations.
I wonder does the yamaha preamp have a "Direct" setting? You see where i am going with this. Whether listening to digital or analog programming, everything connected to or switched onto the signal path can effect sound repro etc etc. 

Next, interconnects and cables. Although, some here will disagree, there are modestly priced speaker cables that WILL dramatically effect the quality of sound your Yamaha or any piece of HT kit will reproduce. Unfortunately as their popularity grows so to their price. I am using Kimber Kable 8TC - multiple wire sizes of oxygen free copper (99.99 pure OFC) individually teflon coated is recommended for longer runs and/or dynamic and difficult speaker loads or any speaker. A neutral speaker cable able to deliver accurate dynamics and a large soundstage. Features sixteen individually insulated strands of OFC copper wire that have been Teflon coated and braided into one monolithic cable and reasonably priced. They make better cables and others that did NOT work for me. The Kimber 8VS reinforced bass and mids but lacked a full spectrum sound.
Also, Audioquest is pricey but an excellent cable manufacturer as is Furutech, Cardas, 

Enough, i'm preaching to the choir. Just sayin' i like that this topic is resurrected


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## 3dbinCanada

I'm not surprised either that tube amps sound different than SS amps. The question should be do all solid state amps sound the same?


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## Oleson M.D.

3dbinCanada said:


> I'm not surprised either that tube amps sound different than SS amps. The question should be do all solid state amps sound the same?


Amplification is not supposed to have any "sound". If done correctly, the job is to make audible what the recording engineers dictated for the final audio mix.

Good quality amps and preamps should not affect what we hear as listeners.


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## 3dbinCanada

Oleson M.D. said:


> Amplification is not supposed to have any "sound". If done correctly, the job is to make audible what the recording engineers dictated for the final audio mix.
> 
> Good quality amps and preamps should not affect what we hear as listeners.


Agreed but tube amps run with a lot of harmonic distortion which "warms" up the sound. I'm not saying its wrong or right..just different for tubes.


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## RAJBCPA

Over the years, I have owned about 30 receivers [Denon, Yamaha, Marantz, Pioneer, Sony]. I have owned about 12 pre-amplifiers [Denon, Marantz] and probably 6 dozen power amplifiers [Denon, Marantz, Crown] I have owned several subwoofers - 18 inch JBLs, mostly in 8ohm trim [about 12 in total]. 

Speakers make the biggest difference but this is not a speaker threat.

Since Denon and Marantz merged at least 10 years ago, I cannot hear any difference in these power amplifiers, pre-amplifiers or receivers. The units are laid out differently internally and look different when the covers are removed.

Yes - Denon/Marantz power amplifiers, pre-amplifiers and receivers sound much better than a Yamaha, Sony, Pioneer or Onkyo receiver. The Yamaha receivers are light and day BETTER than the Pioneer and Onkyo receivers, however.


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## 3dbinCanada

RAJBCPA said:


> Over the years, I have owned about 30 receivers [Denon, Yamaha, Marantz, Pioneer, Sony]. I have owned about 12 pre-amplifiers [Denon, Marantz] and probably 6 dozen power amplifiers [Denon, Marantz, Crown] I have owned several subwoofers - 18 inch JBLs, mostly in 8ohm trim [about 12 in total].
> 
> Speakers make the biggest difference but this is not a speaker threat.
> 
> Since Denon and Marantz merged at least 10 years ago, I cannot hear any difference in these power amplifiers, pre-amplifiers or receivers. The units are laid out differently internally and look different when the covers are removed.
> 
> Yes - Denon/Marantz power amplifiers, pre-amplifiers and receivers sound much better than a Yamaha, Sony, Pioneer or Onkyo receiver. The Yamaha receivers are light and day BETTER than the Pioneer and Onkyo receivers, however.


Unless backed up by blind listening tests, I doubt very much that there is difference in sound when all DSP is turned off.


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## jonathonsmith

Sonnie said:


> *Can we really hear a difference between two amps?*
> 
> More specifically... between two amps that have been level matched in a controlled listening test. We are not talking about amps that have been modified or are driven beyond their reasonable limits.
> 
> What a crazy and completely worn out question... I know, I know, but I figured why not have a bit of fun with it anyway.
> 
> Naturally our ZERO TOLERANCE FORUM RULES are going to apply as they ALWAYS do! So... if you are one of those who simply cannot have a sensible discussion on a hot and debated topic... STAY FAR AWAY from this thread.
> 
> Consider the following link and quoted articles:
> 
> *LINK*: *Science and Subjectivism in Audio*
> 
> I have leaned towards the camp of not being able to hear any significant difference between almost any two amps out there when played at moderate levels on the typical speaker system, unless there is something wrong with one or the other amp that might cause it to color the sound.
> 
> Granted... a low-end receiver may well have an issue driving a system of certain electrostatic speakers... or speakers with low sensitivity, especially if pushed to higher levels. There are going to be exceptions, but for the sake of this discussion, let's say we are using a pair of Klipsch RF-62 II speakers with a sensitivity of 97dB @ 2.83V / 1m ... or perhaps the Duntech Marquis speakers that Zipser was using above at 92db.
> 
> I have owned processor/amp combos and/or receivers from Sony, Denon, Sunfire, McIntosh, Adcom, NAD, Onkyo, Earthquake, Anthem, Rotel, Lexicon, Emotiva (and probably others I cannot remember) powering Snell B-Minors, Klipsh Forte, PSB Image, SVS, JBL, Boston Acoustics, VMPS RM30's, MartinLogan Ascents, ML Spires and recently the older ML Prodigy mains with a Theater center and Ascent surrounds powered by Emotiva XPA-1's and an Onkyo 906 Receiver. Currently (updated January 2104) I run an Onkyo 5509 with an Emotiva XPR-5 with MartinLogan Montis, Stage X and Motion 12's. The most significant difference I ever heard was moving to the Martin Logan speakers. NOTHING had EVER made anywhere close to a difference in sound as did the MartinLogan speakers. I thought at one time that my NAD receiver had more of a soft sound (maybe "warmer" as some will state the description), but was told (never did verify it with NAD or via measurements) that NAD intentionally setup their receivers with a rolled off high-end. However, I have heard significant differences in speakers. I have also performed A/B testing between several amps and have not found any differences outside of clipping and/or distortion.
> 
> Is it not the desire of the audiophile to have electronic equipment which does not alter the sound?
> 
> Your thoughts and comments will be interesting.



No. You can only feel the difference. Here are some of Best AV Receivers Under $1000 which will help you to get in-depth knowledge of AV Receivers. Do give it a read.


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