Replacing a switch with a pot

[alparent]

Lets say I have an effect and it as a 1P1T switch to add the dry signal. But with that switch it's all or nothing.
What if I wanted to replace that switch with a pot so I could dial in the amount of dry signal I wanted.

How would I wire that and what pot value and size sould I use?

I did research this ........ found info ....... but stile wondering. 

Thanks.

[Fender3D]

It depends from the effect, of course.
With a phaser or flanger maybe "lotsa less" might behave as "nothing", with echo or reverb "lotsa less" will be "it's always there".

You might wire it as a volume control, probably with VREF instead of GND if it lies beetween op amp stages or decoupled with caps.

If you provide a schematic we may help better...

[alparent]

this is the one

http://sites.google.com/site/distorque/home/projects/pictures/DP%20Modded%201-1.png

the 2 switches or next to each other.

Would changing them for pot be worth it?

[Fender3D]

You'll have a hard time with that schematic...

You might use the Delay2's op amp between pin 13 and 14.
Put a resistor instead of short, then look at R.G.'s "panning for fun" at Geofex for the math...

signals from R8 and R3 and R24 (or pot) will go to pin 13, effect out from pin 14