The Formula 69 is a modern recreation of the classic late 60's, early 70's Fuzz Face circuit with a few tweaks and modifications to improve tone and versatility. Germanium fuzz faces are very temperamental as they react differently depending on the ambient temperature, guitar, amp, other effects in the chain, and of course, bias setting. Silicon Fuzz Faces are more reliable and consistent however they have a reputation of being harsh and too "high gain".
In order to address these issues, the first change was to fit the circuit with lower gain silicon transistors. With these hand selected transistors, there are no significant issues with temperature changes, oscillation, or radio interference. Furthermore, the tone switch completely alters the pedal's voicing as it allows the user to select a full and thick fuzz or to reduce the bottom end, resulting in a less woofy yet rich tone that cuts through the mix with ease! The external Bias control drastically changes the effect's midrange content and response. The pedal is highly responsive and cleans up extremely well as the guitars volume is rolled back.
The Formula 69 offers the best of both worlds...warm, soulful tone with loads of fuzz, in a modern, compact, consistent and reliable package.