# Preamp for 2 channel system, suggestions and questions



## Jetjones (Jan 29, 2012)

I am looking for opinions/suggestions on a preamp for my 2 channel system. I am open to buying used so that I can get more for my money. I will be using this preamp along side either an Emotiva amp or a proamp. My budget is $400 to $700 dollars. I don't need anything fancy, my only request is that it sound as best as possible for my budget. I really do not know much about the purpose of a preamp other than it is used as a volume control and source switcher. I will be using this for cd playback only but might be interested in using something like a Squeezebox one day as well. Any suggestions?


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## erwinbel (Mar 23, 2010)

Hey fellow Emotifan!


I have a pair of Jamo R909 speakers that can go deep and loud. The XPA-1 pair is doing just fine. The main source is a Mac mini. That's why I went for the Weiss DAC2, which I use as a pre-amp: I only need attenuation and DA conversion, no pre-amplification. The high gain of the Emo amps (32dB) further reduce the need for a normal pre-amp. 

If I were you and don't needed a DAC, I'd try a passive magnetic pre-amp. This doesn't "attenuate" the volume like a normal volume control, rather "converts" the high voltage / low current into a lower voltage / higher current, thus preserving all the nuances of the sound, unlike a normal VC...

I like the manual balanced Stereoknight Silverstone , which is a gorgeous design for about $1,000. I presume the unbalanced SE model will be about half the price. 

http://www.stereoknight.com/silverstone passive preamp.html

The thing is made in China, but the Chinese/American designer/owner is based in Tennessee, just like Emotiva...

I can tell you I will add a remote "B&R" version later when I will need to deal with more sources (a sat PVR, a turntable, a radio)


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## Jetjones (Jan 29, 2012)

erwinbel said:


> Hey fellow Emotifan!
> 
> 
> I have a pair of Jamo R909 speakers that can go deep and loud. The XPA-1 pair is doing just fine. The main source is a Mac mini. That's why I went for the Weiss DAC2, which I use as a pre-amp: I only need attenuation and DA conversion, no pre-amplification. The high gain of the Emo amps (32dB) further reduce the need for a normal pre-amp.
> ...



I have looked into the idea of using a passive preamp before, and they can be found for much less than the one you posted a link to. I don't know, Im not sold yet on the idea of using a passive preamp. I would like to try and find a dealer in my area that would allow me to bring home a preamp and dac to try in my system so that I can get a good idea of how they compare with my current avr that I am using to power my 2 channel sytstem right now.


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## erwinbel (Mar 23, 2010)

Jetjones said:


> I have looked into the idea of using a passive preamp before, and they can be found for much less than the one you posted a link to. I don't know, Im not sold yet on the idea of using a passive preamp. I would like to try and find a dealer in my area that would allow me to bring home a preamp and dac to try in my system so that I can get a good idea of how they compare with my current avr that I am using to power my 2 channel sytstem right now.


A passive preamp and a passive magnetic preamp are 2 different things. A cheaper passive "chokes" the current, with loss of resolution as a consequence. Very hard to get right.


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## Jetjones (Jan 29, 2012)

erwinbel said:


> A passive preamp and a passive magnetic preamp are 2 different things. A cheaper passive "chokes" the current, with loss of resolution as a consequence. Very hard to get right.




Can you explain the difference between a passive preamp and a passive magnetic preamp? Are either one worth looking into?


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## erwinbel (Mar 23, 2010)

Jetjones said:


> Can you explain the difference between a passive preamp and a passive magnetic preamp? Are either one worth looking into?


A magnetic preamp acts like a transformator and transforms a high voltage current into a lower voltage (=attenuation) with higher current (=compensation for the loss in resolution).

A conventional passive lowers the voltage by choking it and turning it into heat.

Here's a nice read:

http://www.adventuresinhifiaudio.co...ifiers-part-one-the-silverstone-br-reference/

My plan for my 2ch AV set-up is this: 
preamp: Stereoknight Silverstone B&R (has a remote)

inputs: 
Turntable Project (RCA) 
Weiss DAC2 (which is positioned next to it's Mac mini source, XLR interconnects, some 5 meters from the rack)
Oppo 95 (XLR for stereo audio, HDMI to the teevee)
Tuner FM (RCA) because internet radio sounds hopelesly metalic to my ears
Sonos (RCA)
Satellite PVR (RCA for stereo, HDMI to teevee)

outputs: 2 x XPA-1 (Jamo R909 speaker) 
The Emo amps have very high gain (32 dB) hence need more attenuation from the preamp than most. They will love the Silverknight since this sounds better the more you attenuate. Right now, the Weiss DAC2 acts as preamp. This sounds better the louder you play. The bass from the R909 is so tight you could cut a country in half with it...

And another neat feature from the Silverknight is it turns unbalanced RCA into XLR.

PS, just noticed I got 4 RCA sources and only 3 are on the preamp... Choose between the tuner and the sonos then. Or use a RCA to XLR connect? Or I could hook up the sonos digitally to the Weiss DAC2.

An older example, very expensive:

http://www.6moons.com/audioreviews/musicfirst/passive.html

6moons on the Silverstone:

http://www.6moons.com/audioreviews/stereoknight/1.html


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## lcaillo (May 2, 2006)

The short answer is that a magnetic passive uses some form of transformer while a simple passive uses resistive attenuation. The latter is subject to impedance mismatches that can result in level varying frequency response while the former is subject to frequency reseponse aberations across levels if poorly designed.

As the link in the above post states, the devil is in the details. There are such good active devices available that I don't see the reason for passive devices these days.


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