solid state, unity gain preamp

[lordearl]

What is the best way to build one of these?

I've tried passive preamps (no gain is great, but life is sucked out of the music) and active preamps (sound is great, but they're far too loud) but would like to venture further and try a preamp which is essentially a buffer with a volume control.

People seem to be stuck in one camp (active) or the other (passive).

Any suggestions on a PCB or kit which might be a good starting point?

Cheers!

 

[Calvin]

Hi,

if done right a passive switched resistor network doesn´t suck life out of music, but can be the most neutral, dynamic and well sounding way to control volume.
A simple buffer should than only be needed with cable runs of more than 10m. I would opt for a simple JFET sourcefollower made up from two N-channel JFETs (see Erno Borbely´s Website about those). Besides beeing sonically a hell of a good thing, the building effort remains easy and small.

jauu
Calvin

 

[alexcp]

Another is Nelson Pass' B1 preamp - it was designed exactly as an answer to "passive preamps sucking life out of music". I built one using switched resistors volume control from DACT (DACT - Danish Audio ConnecT), and it sounds great. I believe you can order PCBs from Pass Laboratories or download Gerbers and make one yourself.

 

[planet10]

At the moment diy versions of the FirstWatt B1 are the SS unity gain pre of choice.

dave

 

[Gordy]

Yes, the simplest implementation of a unity gain preamplifier is probably the Pass B1:

http://www.diyaudio.com/forums/pass-labs/124889-b1-buffer-preamp.html

http://www.diyaudio.com/forums/pass-labs/154531-b1-builders-thread.html

http://www.diyaudio.com/forums/pass-labs/145201-building-symmetrical-psu-b1-buffer.html

 

[lordearl]

Well that was easy, will give it a go!