RO Guitar Preamp 9: Clean Boost with 2-Voice Fuzz and 2-Band Tone PUBLIC

Richter Original Guitar Preamp, Version 9; Clean Boost w. 2-Voice Diode Fuzz and 2-Band Active Baxandall Tone.

Richter Original guitar preamp, version 9; clean boost with 2-voice diode fuzz and 2-band active Baxandall tone circuit. Controls Include: Input Level, Gain, Fuzz 1 enable switch, Fuzz 1 symmetry switches, Fuzz 1 Depth, Drive, Fuzz 2 enable switch, Fuzz 2 Depth, Bass, Treble, Trim, and Volume. The IC was chosen to ensure clean op-amp operation at all control settings. Fuzz 1 voice is from Schottky diodes in a feedback array, and with constant gain boost. Fuzz 2 voice is from standard diodes in a shunt array. Frequency Range 22 Hz to 5.6 kHz with all controls at 50% but no fuzz, or 10 Hz to 10 kHz with all controls at 100% and Fuzz 1 full. Suitable for 6/7/8-string guitar or 4/5/6-string bass. Maximum Gain = +20 dBV from 250 Hz to 400 Hz with all controls at 50% but no fuzz, or 22 dBV with all controls at 50% but Fuzz 1 full, or +25 dBV with Gain at 100% but all other controls at 50%, or +57.5 dBV with all controls at 100% but no fuzz, or +58.7 dBV with all controls at 100% and Fuzz 1 full. Fuzz 2 has little/no effect on overall gain. A 12-volt battery is shown but can be replaced by a regulated single-polarity DC supply providing +12VDC @ >= 50 mA of current. Rackmount implementation is recommended. And though simulator verified, treat the circuit as experimental. Breadboard test before committing to a soldered build. If overdriven op-amp distortion is desired in addition to fuzz, consider the following substitutions for the IC. For JFET distortion, use the TK082CP. For MOSFET distortion, use the OPA2156IDR. For tube-like BJT distortion, use the NJM5532M (the Japanese version of the NE5532N, which does not sound the same).