Schottky Fuzz w. Fender Tone-Stack PUBLIC

Schottky Fuzz Circuit with 3-Band Fender-Style Tone-Stack

Fuzz circuit using one dual JFET-input op-amp IC, eight Schottky diodes in a hard-clipping array, and a 3-band Fender-style tone-stack. Controls Include: Input Gain, Drive, Overdrive, Fuzz Enable switch, Fuzz symmetry switches (two, with 2 positions each), Fuzz Depth, Bass, MId, Treble, Stack Sum, Output Gain, and Volume. With the Diode Array disabled, circuit will serve as a medium-gain boost (but not as an overdrive). With the Diode Array enabled, the fuzz will be the deep kind from doubled-up Schottky diodes, but output volume will be reduced. The symmetry switches set harmonic content of the fuzz (imbalance between legs in the Array introduces more odd-order than even-order harmonics). For op-amp distortion in addition to fuzz, overdrive the Input Stage and turn both Gain controls towards 100%. Suitable for stomp-box or rack-mount applications. The battery can be replaced by a regulated single-polarity +9V DC power-supply providing >= 10 mA of total current. Range above 0 dBV is from 25 Hz to 10 kHz. Low -3 dB cutoff is at 22 Hz. High -3 dB cutoff is at 13 kHz. Thus, the circuit is good for 6/7/8-string guitar or 4/5/6-string bass, in standard tuning, with emphasis on the mids. Max gain = +20.5 dBV @ 400 Hz with all controls at 50%, or +26 dBV with both Gain pots at 100%, but all other controls as 50%. Maximum total gain >= 30 dBV with all controls at 100%, but not recommended except as a worst-cast test during breadboarding.