[sdiy] Dumb mixer circuit question

[Tom Arnold]

While I'm asking questions, this is one that's been bugging me for a few
days...

Lets assume standard virtual ground mixer.  Normal dual opamp with both stages
inverting.  Easy enough.  Now I want to add level controls to each input and
this is where I get torn...  I see a lot of people do it by just putting a
pot on each input, but I've played with this and found that this can affect
loading of whatever is plugged into the mixer.  My thought is to up my opamp
count a bit, use an inverting stage per input for isolation, then add the pots
after the first inverting stage but before the final inverting/mixer stage.

I'd probably use 3 TL072's with a '71 mixer, possibly upgrading the opamps
later to something that sucked a little less.  I'm just looking for opinions
on the added complexity vs what everyone seems to already do.  I've noticed
that commercial mixers seem to do it the way I'm thinking of doing it.


-- 
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 - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org 
 - SynthGeek        -
 - BBD Fanatic      -  "...is it a virus, a drug, or a religion?" 
 - echo evho wjxo   -    Juanita Shrugs. "What's the difference?" 
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