MOSFET Fuzz Circuit 4 PUBLIC

High-Gain MOSFET Fuzz Circuit 4

High-gain MOSFET fuzz circuit 4, for electric-guitar. Uses one dual JFET-input op-amp for gain and two dual MOSFET ICs for fuzz. Controls Include: Drive, Gain 1, Gain 2, Intensity, Tone, Post-Gain, and Volume. The Input Stage uses one op-amp with fixed gain to drive two fuzz circuit in-series with each other. The fuzz comes from overdriving an enhancement-mode MOSFET chip containing one P-channel and one N-channel complementary-pair MOSFETs within the same package, and also putting two such circuits in-series, so the first can overdrive the second, each with adjustable gain. Furthermore, each MOSFET chip is configured to perform as a unity-gain inverting buffer using Zener diodes. This kind of arrangement is known for producing tube-like fuzz-tone. Frequency range above 0 dBV is from 32 Hz to > 20 kHz with all controls at 50%, with emphasis on upper-mids and highs. Thus, the circuit can be used with 6/7/8-string guitar or 4/5/6-string bass, in standard tunings. Maximum gain = +31.5 dBV @ 1.6 kHz with all controls at 50%, or +62.3 dBV @ 1 kHz with all controls at 100%. Circuit is suitable for stomp-box or rack-mount applications. The battery can be replaced by a regulated single-polarity +9V DC supply providing >= 25 mA of current. And while simulation verified, treat the circuit as experimental. Breadboard test before committing to a soldered build. House completed project in a grounded metal enclosure.