Here’s mictester’s advice on tweaking:
“Adjustment: set the 1k “Abuse” pot halfway. Play though it, and adjust 5k preset until “gating” just stops. That’s it!
Possible mods:
Put small value capacitors from base to collector of the middle two transistors – start with 47pF. This “smooths out” the sound a lot, but reduces the treble available.
If you have radio interference, put 100pF from base of the first transistor to ground.
Experiment with the capacitor values in the tone control – the 8n2 could go as low as 3n3, which would give a ridiculous range of treble control!
Increase the value of the 47k feedback / bias resistor – try as high as 470k. The gain will rise, the touch sensitivity will disappear, and it will become a high gain screaming monster! “
Now – here’s a similar design posted back in 2003 by Gus Smalley; the “Hot Silicon”:
Take away the furore over circuit credits and what not and you’ve got a great sounding design here – it’s an absolutely cracking fuzz circuit (I actually prefer it to messing about with Germanium transistors!). Give it a try – you won’t be disapointed!
And here’s an image of a completed build by LaceSensor:
