Dual gang pot for boost

[runraven]

Hello everyone. First timer here. I have a boost circuit that I am retrofitting into a volume pedal. I want (the tone part of circuit is passive) the mid control to  correspond to the main tone control as in when I rock the pedal back and forth, the mids are being cut and increased in time as the main tone is being cut and increased. The two values are 100k &25k. I have done some searching for a dual pot that has these two values, but so far, no results. Would like to know anyone's experience with trying this kind of thing or am I S.O.L.? Thanks so much!

[antonis]

Hi & Welcome.. 

Dual gang pots (despite their taper) of different values are commercially rare..

But you can use a 100k dual gang one and wire a 33k resistor across outer lugs of one gang..
(original taper should be violated but you'll get acceptable result..)

[ElectricDruid]

Welcome,

I agree with Antonis - you won't find a 100K/25K pot anywhere. Pot manufacturers will make you such a thing if you're willing to order 100,000 units, but otherwise forget it. That suits Boss for their pedals maybe, but doesn't leave the rest of us with many options.

Your options are to either re-design the tone circuit to use the same value as the volume part (or vice versa) or to parallel up another resistor to adjust the value like Antonis suggested.

[runraven]

 Oh yes, why didn't I think of that? Guess that's why I use forums. Thanks a bunch, I will try this!

[iainpunk]

you could also do a potentiometer resistive transplant surgery... if you dare
you get yourself a dual 100k and a normal 25k pot
you pry the case open really carefully, and swap the resistor wafers between the 25k and one of the 100k.
this leaves you with a normal 100k and a 100k//25k dual.

cheers

[ElectricDruid]

you could also do a potentiometer resistive transplant surgery... if you dare

Yeah, good point! This is possible, if a little tricky. But it's been done a lot of times before now.