# Choosing an Amplifier



## majorloser (May 25, 2006)

I'm in the market for a new amplifier to replace my B&K Ref 7270 (long story). I will still be using my B&K Ref 30 processor (upgraded to Ref 31). The Ref 31 does not have ballanced outputs so it's not a big deal if the amp has them or not.

I was just looking for some opinions on the following amps:


Gemstone Audio Blue Diamond
Outlaw Audio 7700
Emotiva MPS-1

They are all listed at 200W per channel. I'm leaning toward the Emotiva MPS-1 since I like the modular design. It's selling for $1,699.00 right now.


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## AverageJoe (Jun 29, 2006)

Well, this may not be much help, but...

I'd pick the Emotiva for one highly technical reason: I'm a sucker for those cool blue lights - they look awesome.


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## Josuah (Apr 26, 2006)

The Emotiva is definitely the best value for the money. But the Gemstone doubles its power when running 4ohm loads. From what I understand, that means it's power supply is better than the Emotiva (I wonder if that translates to lower noise floor--I have no idea) although if your speakers are 8ohm nominal or you don't need 400W at 4ohms you probably couldn't care less.


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## Sonnie (Apr 11, 2006)

Hi majorloser and welcome to the Shack!

I know you state "long story", but is it broke or you don't like it?

I noticed a couple of 7 channel B&K's on Audiogon in the $1700-1900 range.


The Gemstone is going to give you more headroom/dynamic power but at a significant cost.

The Emotiva I think will out spec the Outlaw and be a little less cost... look better IMO, but I can't comment on the sound of either.

I came within a smidgen of buying the Emotiva DMC-1 and if it had onboard HDMI switching, it would be at my house right now. 

Of those three, my vote (unheard) would go to the Emotiva... seems like the best bang for the buck.


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## Josuah (Apr 26, 2006)

I would assume the MPS-1 and 7700 are going to be almost identical in performance. Now, Audioholics did measure the MPS-1 as delivering slightly less watts than advertised, IIRC. I don't know anyone who has measured the 7700. On the other hand, the MPS-1 is advertised as stable into 2ohms, but I don't recall reading that about the 7700 when I was comparing. If you use the signal-trigger on the MPS-1, you could theoretically save some electricity by using that for your 2-channel listening. But I found the click when it turns on too annoying to leave it in that mode because you might trigger a channel mid-movie.

I can't really comment on the 7700 myself as I haven't tried it in my system, but the 7125 which I was using before I bought an MPS-1 didn't sound any better to me than the amp section off my Yamaha RX-V1400. I can't say the MPS-1 does either though, as I swapped it in the same time as the DMC-1 so all I can say is that pair sounds better to me than the RX-V1400 + 7125 pair.


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## majorloser (May 25, 2006)

Sonnie said:


> Hi majorloser and welcome to the Shack!
> 
> I know you state "long story", but is it broke or you don't like it?
> 
> I noticed a couple of 7 channel B&K's on Audiogon in the $1700-1900 range.


Let's just say I'm tired of shipping my Ref 7270 back to the factory for repairs. No matter what happens this time, it's not going back in my theater.

I have a new twist to my decision making process. I'm thinking about buying seven Behringer A500 amps and running them bridged for 500W at 8 ohms. I found them for $179 each shipped. A lot more power for less money. Granted it makes for a big stack of amps. But think of how cool it'll look!


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## Josuah (Apr 26, 2006)

Don't forget the fan noise. Also, I assume then your speakers are 8ohms nominal. If you bridge the A500 amp the minimum load must be 8ohms.


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## Sonnie (Apr 11, 2006)

That would be interesting and definitely an inexpensive method of amplification.

Do those Behringers have fans? I'm not familiar with them, but I'm thinking modification... and what kind of current draw might be a consideration running 5 of them.


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## khellandros66 (Jun 7, 2006)

You should also consider the Amplifier Technologies AT2000 series which is modular. 

ATI-AMP AT2000

~Bob


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## majorloser (May 25, 2006)

Sonnie said:


> That would be interesting and definitely an inexpensive method of amplification.
> 
> Do those Behringers have fans? I'm not familiar with them, but I'm thinking modification... and what kind of current draw might be a consideration running 5 of them.


No, the A500's do not have fans. The EP1500 and EP2500 do have fans.
The A500 specs state it draws 6.5 amps at max load.
http://www.behringer.com/A500/index.cfm?lang=ENG

:rolleyesno: The ATI is too rich for my blood right now. Retails for $3,995. That's 2 to 3 times the price of the others.

I can get 7ea. A500's for $1,253 ($179ea.) with free delivery and an additional one year of warranty. And that would give me 500 watts per channel. And considering I have 80 amps of dedicated power in my component closet, giving them enough power ain't a problem.

(Bob, so this is where you went after leaving Audioholics. Nice to hear from you!)


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## Danny (May 3, 2006)

Seems like a good idea, pro amps seem to have more power per dollar than the HT amps. I doubt you'll be drawing 6.5 Amp very often, esp since you wouldn't need 500 Watt / ch for the HT.


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## majorloser (May 25, 2006)

Well, I ended up buying seven (7) Behringer A500's from Americanmusical.com
$179 each, free shipping, one year extended warranty and 0% interest 5 monthly payments.

We'll see how they work out.


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## Sonnie (Apr 11, 2006)

Be sure to update us on the results.


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## majorloser (May 25, 2006)

Well, the Behringer A500's arrived today. Now for the task of getting them to fit on the rack. I went from one 80 lb. amp to seven 20 lb. (I just hope the rack will roll when I'm through.) I will say that the amps are better quality construction than I expected. Heavy gauge steel and alluminum.

I should have everything up and running by this weekend. I'll let you know how things go.

EDIT: I have to wait for some connectors and cable to arrive. Will take a few more days.


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## majorloser (May 25, 2006)

Well, the A500's are up and running. :jump: 

Everything is working GREAT. It's a definite improvement.

Check out my post thread at: http://forums.audioholics.com/forums/showthread.php?t=22943


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## eddthompson (Aug 19, 2006)

you know, i like pro amps, have a real thing for them.

my 3 amps look beastly, i bet 7 looks absolutly menacing.

edd


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## Pupton (Jul 15, 2006)

Has anyone run any compares of the A-500s to the new Emotiva Ultra-Lite LPA-1? Looks like similar specs and (3) A-500s would be about the same price?

I'm thinking of adding some outboard power (currently just using internal power from my Yamaha RX-V3000)...

Thoughts?


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## eddthompson (Aug 19, 2006)

Hi, unfortunatly i have no experence of any of your compnents or the one your looking at, but going by this:

your speakers are not that efficeint, 86db, there also a slightly awkward load of 6 ohms rather than the usual 8.

So, you current amp has a power supply rated at 480watts, minus a bit for efficiancy and your at less than 100 watts per channel with all 5 driven.

The emotiva has a rating of 1500 watts, and claims up to 225 watts into 4 ohms per channel, much more powerfull, which is good :devil: (almost twice as powerfull into 6 ohms i reckon)

The behringer gives 230 watts into 4 ohms, so they are very similar power wise, and as such i wouldnt expect to much difference in performance between the 2 options. I suppose i boils down to 6 or 7 channels, 1 box or 3 boxes.

If i lived in america (which i dont :no: ) id probably get the emotiva, or, pro amps bit more powerfull than the a500, although fan noise becomes an issue. oh and the emotiva has a 5 year warrenty, which is nice.

edd


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## Sonnie (Apr 11, 2006)

Actually you would be getting less than 225 wpc into 6 ohms, if that rating is into 4 ohms. You might check to see if the emotiva has a rating into 6 or 8 ohms... which will be less than the rating into 4 ohms.


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## majorloser (May 25, 2006)

The Behringer A500's do not have fans. I have run them continuously for over 4 hours and they barely get warm. Please note that I'm running all seven amps bridged in mono for 500 wpc into 8 ohms.


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## eddthompson (Aug 19, 2006)

Sonnie said:


> Actually you would be getting less than 225 wpc into 6 ohms, if that rating is into 4 ohms. You might check to see if the emotiva has a rating into 6 or 8 ohms... which will be less than the rating into 4 ohms.


yes, but as the 8 and 4 ohm rating for the both the a500 and the emotiva are almost identical, i assume 6 ohm performance will be the same, and i stand by the thought they will double the power of the cuurent amp, ie even at 6 ohms the most his current amp will provide will be 400/5 (assuming it pretty efficient) which is 80 watts a channel all channels driven, im pretty sure into 6 ohms the behringer and emotiva will manage a good 160 odd watts.

this is all very rough of course

edd


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## eddthompson (Aug 19, 2006)

majorloser said:


> The Behringer A500's do not have fans. I have run them continuously for over 4 hours and they barely get warm. Please note that I'm running all seven amps bridged in mono for 500 wpc into 8 ohms.


i wasnt implying they did have fans, you have the real advantage of running them bridged providing 500 odd watts a channel. but i belive in this case he is looking at 3 of them, not 6, and in this case the emotiva provides very similar performance for approximately the same price, in one box.

Im not sure, but i thought maybe in the usa you could grab more powerful crowns (where th fan nouise creeps in)or qscs for around $200, but having looked i see the crowns are around $400 per amp.

In the uk we have nothing like emotiva, outlaw, even sunfire, aragon etc, when i was looking for high power amps i was looking at rotel or arcam (neither of whcih are that high power), the rest of the market is dominated by integrateds, nothing compares to the value of pro amps here, even the a500s, i beilve in the usa, there are other viable options. I wasnt being biased either way, just stating what id go for given the oportunity.

edd


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## Pupton (Jul 15, 2006)

Thanks for the feedback!

Majorloser, based on your (and others) thoughts, I'm really considering (3) of these for my 5-ch (plus 1 ch for my bass shakers, which I use at late-night when the IB is off)...

Here's the specs I found:

A500: [email protected], [email protected], [email protected](Mono)
UL: [email protected], [email protected]
Both have SN Ratio of -100db

I'm sure my 6ohm NHT will fall in between these figures and it will be a step up from the Yammy's power.

Thanks,

Mike


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## eddthompson (Aug 19, 2006)

my apologies( i thought the behringer was 120 watts at 8ohm), asuming performance into varyingloads in linier from 8 to 6 ohms, the a500s should get pretty close to its 4ohm rating into 6ohms, i say this beacuse assuming the powersupply was good enough, 160 into 8 ohms should be 320 into 4, so half way between that is 240 watts.

So the behringers may have the advatge in power, which, as far as im concerned, is pretty much the only thing i look at :laugh: 

of course make sure you can send them back is you hate the sound :R 

edd


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## Pupton (Jul 15, 2006)

edd ,didn't see your posts prior to mine... I do like the fact the UL has the nice warranty and is in one chassis... it's just good to know there are several options to run a decent system at these prices....

Regards,

Mike


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## Sonnie (Apr 11, 2006)

eddthompson said:


> yes, but as the 8 and 4 ohm rating for the both the a500 and the emotiva are almost identical, i assume 6 ohm performance will be the same, and i stand by the thought they will double the power of the cuurent amp, ie even at 6 ohms the most his current amp will provide will be 400/5 (assuming it pretty efficient) which is 80 watts a channel all channels driven, im pretty sure into 6 ohms the behringer and emotiva will manage a good 160 odd watts.
> 
> this is all very rough of course
> 
> edd


Thanks for clarifying... when reading your post it sounded like you were saying that 6 ohms would be twice the power of 4 ohms, but weren't sure. I understand better what you meant now.


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## eddthompson (Aug 19, 2006)

:R :R i can come across very confusing, im slightly dyslexic and have real issues comunicating in wrtten form.

Unfortunatly all this av nonsence interests me greatly, and i cant help driveling on this sort of forum, and i particularly like this little hub of avnuts far from the madding crowds (avforums, avsforums)

anybody who can even plug in a bfd, let alone fire up rew deserves attention :wave: 

edd


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## majorloser (May 25, 2006)

I know some guys have been waiting for my impressions of the Behringer A500's. Sorry it took me so long.

So far I've tried just about every kind of media I care to run in my house and have had nothing but great performance out of these budget amps. I'm running them bridged and the gain knobs are set at two click past the middle point. PLENTY OF POWER (500wpc bridged). I'm glad I made the switch to separate amps. The multi-channel option really became a PITA after awhile. The B&K could cook meat after a couple hours and if you have a problem with one channel the whole system is down. Nothing like sitting there staring at a silent picture while your waiting for the amp to come back from the shop. :hissyfit: 


I guess I can sum it up with my positives and negatives lists:

*Positives:*
>They run very cool. After 5 or 6 hours of continuous use they barely get warm. My pre/pro gets hotter.
>More wattage available in bridged mode than most persons will ever need in their setup.
>Inexpensive compared to multi-channel options
>Ability to run as stereo or bridged mono for added versatility.
>Cool looking LED lights. (seven amps can become hypnotizing when the music is loud and the meters are bouncing)
>Multi amps allow me to easily turn on only the channels I need. Don't need seven channels running if I'm only watch TV (only front three)

*Negatives:*
>Those cool looking LED's can get distracting if you place them in the front of your theater and they're *******' bright in a dark theater (mines in a closet).
>Requires more space compared to multi-channel options.
>No remote trigger to turn amps on and off (back to old school)

*All I can say is my Canton Ergo's must be some power hungry hogs because the extra power of the bridged A500's is sure doing them some good * :jump: 
For those of you out there that want some serious power for only $179 US shipped to your door, try some Behringer A500's.


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## eddthompson (Aug 19, 2006)

yup awesome arnt they. only one question though, why do you have the gain turned down on the amps? although ive never encountered any reduction in sound quality from having mine set lower i prefer to leave them set full, and run the pre at a lower volume (and turn down the speakers in the level settings in the pre)

you could be effectivly limiting the power output of your amps, and thus comprimising dynamic range, im sure an expert will tell me if im talking rubbish.

edd


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## majorloser (May 25, 2006)

I don't know. Just didn't need them all the way up. Next time I feel like calibrating I'll try it with them all the way up. My B&K pre/pro should end up turned WAY down.

Maybe I just like to be able to say I'm only half way there :bigsmile:


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## eddthompson (Aug 19, 2006)

turn it to the 11s you know you want to :bigsmile: 

in theory if you turn them all up the same amount, and your pre down by the same amount it should level out? on my behringers the gain is marked -0 to -32 o something, i i drop the the volume to -22 i need to turn the pre up 10db to get where i was on the sound meter, ive no idea why this works, but it does, voodoo i say.

in my pre the individual speakers also run between -5 and -1 db.

edd


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## Danny (May 3, 2006)

If you have your amps cranked the noise from the gear before it will come out full blast, turning down the volume on the amps gives you a better Signal to noise (S/N) Ratio


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## eddthompson (Aug 19, 2006)

i believe as these are power amps the volume control isnt the same as a pre amps. its just input attenuation, and since pro amps need a higher input than consumer, the higher it is the better. 

after all most power amps do not have any form of volume controll.

with my pre switched on, and the power amps at full, there is no noise, none, nadda, coming from my speakers.

edd


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## SteveCallas (Apr 29, 2006)

All your doing in adjusting the amp knobs and receiver channel levels is shifting sensitivity, not limiting amp power output. What it comes down to is whether you trust the internals of the analog pre out stage of your processor more than those in your amplifier. One will create distortions before the other. Personally, I'll side with a discrete high power amplifier almost every time. I'd set the amp knobs to ~80% of max and then adjust your processor channel levels from there - I'm assuming they'd be in the negatives.


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## eddthompson (Aug 19, 2006)

if i took 80% off the power amps, the reciver setteings would be around 0 i guess, currently -1 to -6.

with the power amps at full, and the pre at +12db (full whack) there is a tiny amount of hiss from about 1 meter, inaudible from listening position, this volume would be close to 110db, but more than likely would just blow my speakers.

ill mess about later, i do get the smallest amount of hiss from the bfd, although that seems to go after about 20 mins of being on.

edd


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## Bruce (Sep 14, 2006)

majorloser said:


> No, the A500's do not have fans. The EP1500 and EP2500 do have fans.
> The A500 specs state it draws 6.5 amps at max load.


The A500's 6.5 amp maximum figure interests me. I'm trying to understand various amp specs and how this effects use with specific speakers.

Currently I have main speakers that are listed with 84dB sensitivity (low), they are 4 Ohm Dynaudio Contour towers (center & surround are also 4 Ohm Dyns but different Contour models). When shopping for amps I ended up with a Parasound amp that lists it's current capacity as:


Current Capacity: 45 amperes peak per channel 

200 watts RMS x 5, 20 Hz - 20 kHz, 4 ohms

I know my speakers sound better (full bodied) with higher current amps (after various amp demos).

I'm assuming the A500 wouldn't work very well with these Dyns because of the low current capacity?


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## eddthompson (Aug 19, 2006)

peak supply to the speakers is different to draw from the mains.

on the behringer, 6.5 amps x 120 volts gives you 780 watts, or 390 watts per channel. since it only claims 230 watts per channel, i think that should give very good power and current delivery.

looking at the 5125 specs (looks similar in spec to yours) it rate maximum power draw as 1600 watts, 1600/5 gives you 320 watts, so very similar numbers to the behringer.

edd


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## brucek (Apr 11, 2006)

> on the behringer, 6.5 amps x 120 volts gives you 780 watts, or 390 watts per channel. since it only claims 230 watts per channel, i think that should give very good power and current delivery.


Well, since I suspect this is a class AB amplifier which would have a maximum efficiency of about 70%, in addition to losses in the transformer winding resistance and diodes, I would calculate that (390w x 70% x ~10%) is just about right to result in a 230 watt amplifier. Not much of a revealing indicator there as to the A500's capabilities.

The fact that bruces speakers _"sound better (full bodied) with higher current amps "_ can probably be traced to the simple fact they sound better with amplifiers that produce a lot of power combined with a good power supply. The spec that an amplifier comes close to a "double down" is usually a good indication of a decent power supply including output transistors that can handle that increased current. Although, under-revealing 8 ohm specs to claim a better 4 ohm ratio is a method of fooling this.

brucek


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## Bruce (Sep 14, 2006)

edd,

Thanks for the clarification. Guess I wasn't looking at the right specs. Again thanks.

Bruce


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## eddthompson (Aug 19, 2006)

i was ignoring efficency ill be honest (assuming the parasound and a500 have similar effciancies, you can comparethe maximum watts per channel available, 390 vs 320), i assumed about 70%. i wasnt saying the behringer had more power, i was saying its comparable to the parasound in terms of power supply ability (which both seem to be very good from specs alone compared to say a recievers built in amps).

the a500 comes pretty close to "doubling down" but not quite, the same as most parasounds, my ep1500 however manages to double down to nearly 2 ohms (200 or so into 8, 400 or so into 4, and 750 or so into 2)


edd


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## SteveCallas (Apr 29, 2006)

> Although, under-revealing 8 ohm specs to claim a better 4 ohm ratio is a method of fooling this.


Lol, never considered this. Some audio manufacturers have plenty of tricks up their sleeves.


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## eddthompson (Aug 19, 2006)

which is why an independant review that runs lab tests are handy :bigsmile: 

i always liked the lab testing in hifi world.

edd


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## Guest (Sep 29, 2006)

Hi MajorLoser,
I just got a B&K Ref 30 on ebay. I'm curious, what does upgrading to a Ref 31 get you? And how can it be done?

Thanks for the good info!

Bondster!!


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## majorloser (May 25, 2006)

bondtrails said:


> Hi MajorLoser,
> I just got a B&K Ref 30 on ebay. I'm curious, what does upgrading to a Ref 31 get you? And how can it be done?
> 
> Thanks for the good info!
> ...


Golly (censorship), it's been so long I had to pull both manuals out and compare. I hope I'm right, but:

It added Dolby Pro Logic II, DTS Neo:6, DTS 96/24, THX Ultra2 (Cinema Mode and MusicMode)

If I remember right, the guy at B&K said it brought it up to the processing level of the Ref 50 without the balanced outputs. So it has all of the surround modes of the Ref 50.

WORTH SENDING IT BACK! Give B&K a call.


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