Modified Maestro Fuzz Circuit PUBLIC

Highly-Modified Maestro FZ-1a Fuzz Circuit

Highly-modified Maestro FZ-1a Fuzz circuit. Controls Include: Drive, Fuzz, Intensity, Output Gain, and Volume. The subcircuit topology involving the BJTs is the original FZ-1a circuitry, while the op-amps were added to include more controls and more gain. No tone-controls. Frequency range between the low and high -3 dBV corners is from 52 Hz to 18 kHz. The range between the high and low 0 dBV points is from 58 Hz to 14 kHz, suitable for 6/7-string guitar (not for 8-string guitar or bass-guitar). Maximum gain = +25.3 dBV (Vo/Vi = 18.4) @ 400 Hz, or +58 dBV (Vo/Vi = 794) between 1 kHz and 2.5 kHz. Thus, this is a high-gain circuit when controls are set > 50%. The originally specified BJTs were the 2N270, but which are obsolete and have been replaced here with the readily available 2N3906BU silicon devices. Op-amps were chosen to ensure clean operation except when the BJTs are overdriven. The circuit is good for stomp-box or rackmount applications, while the battery can be replaced by a regulated single-polarity +9VDC providing >= 50 mA of current. And though simulator verified, treat the circuit as experimental. Breadboard test it before committing to a soldered build. And house in a grounded metal enclosure.