This is a modified fuzz, based on a famous one with the slightly rude name. The mods involve two three way clipping switches, carefully selected transistors chosen for maximum warmth and the ability to clean up with use of your guitar's volume control.
This awesome sounding Fuzz is then paired with a notch filter based on the Harmonic Energizer, a rare, virtually unobtainable, vintage eq pedal used extensively by Frank Zappa.
This combination runs rings around the regular tone control for this type of fuzz, as it allows for precise sculpting of the Fuzz frequency response, wailing harmonicly rich feedback, stuck wah type sounds, and near endless sustain.
You can see a demo by clicking the link on the home page, under 'Links'