Simple DIY Pre-Amp (1 Viewer)

[John Klaassen]

I have a little project that I want to try to make a simple pre-amp for. It just needs to have system volume and individual channel volume controls. Does anyone know of instructions somewhere on the internet on how I could do this. I'm going to make it 5 channel, but instructions for 2-channel could just be expanded. Thanks.

--John Klaassen

 

[Michael R Price]

This is fairly complicated, but I would start searching around at http://www.diyaudio.com/forums/forum....php?forumid=4. The preamp circuit itself is not very difficult, but getting accurate level controls for all 6 channels might be... you might be able to use a 6 deck potentiometer (I'm not even sure those exist) and then another independent potentiometer for each channel? I think most multichannel preamplifiers use a microcontroller switching relays to set the volume with a single potentiometer or rotary encoder. A microcontroller could also provide data input to multiple PGA2310 (I think) IC volume controls.

A 2-channel preamp would be much easier, since getting a stereo volume control and balance control is no big deal.

 

[Doug_M_Fraser]

Try the Danish Audio Connect at

www dot dact dot com/html/applications.html

for a 5 channel DIY preamp.

Replace the dot with a . and remove the spaces. Sorry for a reply in this form but I kept getting an error message saying I have not been a member long enough to post a URL.

Doug

 

[Michael R Price]

Aha, it is true that DACT has a 6 channel attenuator (and that preamp too). That's who I was thinking of when I mentioned the multi-deck potentiometer. But that stepped attenuator itself (never mind the rest of that preamp example) costs $400. Holy moly.

Just making a 2-channel preamp, or using a commercially built multichannel preamp, looks better to me. And I can't say I know enough to offer specific ideas if you do decide to build the 6-channel volume control.

 

[ThomasW]

There are lower cost ganged carbon/plastic pots available to the DIY builder. Of course they don't sound nearly as good as stepped attenuators.

And unless one needs 'pre-amplification' for a phono section, a 'passive' preamp works quite well for line-level components. And they cost a whole lot less than an active line stage.