[sdiy] Question 1 - Wet/Dry Mix pot

[harrybissell]

One way is to make an inverting summer (opamp) with two inputs...
tie the pot outside terminals to these resistors. Tie the wiper to
ground.  Then add two more resistors to the pot outside terminals
and use these for the inputs.

In effect you are making two "T" attenuators.  The fixed resistors in
series
with the input limit the current when the wiper shorts one side to
ground.
In mid rotation there is equal attenuation on each side... at either end
one,
or the other input is shorted to ground.

(in another note... I think I first saw this circuit done in a John
Simonton
design, the Gnome iirc but its been a long long time. Someone else can
testify... :^)

got it ?   (if not contact offlist and I can sketch it for you)

H^) harry

Rafael Cohen wrote:

>  Hi,If I am building an effects box and I want to have a single pot
> control the wet/dry (effected/clean) mix, how should I go about that?
> I have a dual 10k audio pot and it seems (I haven't gotten around to
> trying this yet) like if I use that then the log response will act
> differently on the different inputs.  Any recommended
> ways? Thanks, Rafael