This resembles the thick, warm, vintage fuzz sounds of the amazing "Fuzz Face" and "Tone Bender" pedals from the 60's, but their Germanium transistors have been replaced by my silicone transistors and simpler, more efficient circuitry.
Increasing the Attack level results in a crazy, radical fuzz tone, while adjusting the Input Bias on the side can reduce the bass and allows you to drive the amp like a clean booster.

Sound Sample