[sdiy] Dumb mixer circuit question

[Seb Francis]

Tim Parkhurst wrote:
>>
>
> Use one op amp per input and put the variable resistor in the feedback 
> loop?
>


It's kind of neat because you don't get the gain non-linearity (but then 
again when using log pots as you would for a mixer, how close to ideal 
log are they - and does it really matter anyway).

The disadvantage I can think of is that the tolerance between different 
pots is likely a lot worse than 1% when using a resistor.  So each input 
channel would need trimming to get matching gain.

Seb