Adding a gain contol to colorsound fuzz?

[milt]

Hi There,
I've built the one knob fuzz a few times now, I REALLY LOVE this circuit. It sounds so thick and wonderful. Lately I've been finding myself wishing it had a fuzz control or a switch to halve the amount of fuzz or something. Has anyone modded one to act like this?, How could I do it? I'm still a noobie so any help is appreciated.
Thanks a bunch,
Milt.

[Mark Hammer]

If it's this one - http://www.fortunecity.com/tinpan/humperdinck/223/colfuzz.gif - then the simplest thing to do is replace the 1k fixed resistor on the second transistor's emitter with a 1k pot.  Now connect the 10uf cap between the wiper of the pot and the ground connection, using the same orientation shown in the stock diagram.

When the pot is rotated so that the wiper is "closest" to the emitter of the transistor, the 10uf cap will be connected as currently shown, in parallel to a 1k resistance.  As the pot wiper is rotated, the emitter will still see 1k of fixed resistance to ground, but the 10uf cap will be connected to the emitter through whatever resistance lies on the wiper-to-emitter side of the pot.  As that resistance increases, fuzz will be reduced.  That's how the Fuzz Face does it, and it ought to work here too.

Straightforward enough?

[milt]

Thanks a bunch for your help Mark, your post makes perfect sense. I'll let you know how it turns out.
Milt.