RS-Timbre "MOSFET Fuzz 1" PUBLIC

MOSFET Fuzz Using Dual Depletion-Mode MOSFET ICs

MOSFET fuzz circuit using two dual JFET-input op-amps for gain and buffering, and two dual depletion-mode MOSFET ICs for shunt-type hard-clipping fuzz. Note: Depletion-mode MOSFETs are reported to produce a more tube-like fuzz than enhancement-mode MOSFETs.. Controls Include: Input Tone, Drive 1, Gain 1, Drive 2, Gain 2, Fuzz Blend, Output Tone, and Volume. Frequency Range 60 Hz to 40 kHz with all controls at 50%, but Tone controls drop highs down to 10 kHz with both at 0%. Suitable for 6/7-string guitar or 4-string bass. [Not recommended for 8-string guitar or 5/6-string bass.] Maximum Gain = +33 dBV @ 250 Hz with all controls at 50%, or +53.8 dBV @ 10 kHz with Gains, Drives, and Volume at 100%, but all other controls at 50%. The op-amps were chosen to allow for JFET distortion if overdriven, in addition to the MOSFET clipping. For clean operation except for the fuzz, substitute an OPA2134PA for IC1 and IC2. For more tube-like distortion from overdriving the op-amps, in addition to the MOSFET clipping, substitute an NJM5532M for either/both IC1 and IC2. This circuit can be used for stomp-box or rackmount projects. The battery can be replaced by a regulated single-polarity +9V DC power-supply providing >= 60 mA of current. And though simulator verified, treat the circuit as experimental. Breadboard test before soldering.