Modified Elliott Preamp 2 PUBLIC

High-Gain Guitar Preamp with 3-Band Tone and Diode Fuzz

High-gain guitar preamp with 3-band Fender-style tone-stack and Fuzz effect from soft-clipping Schottky diodes in a hard-clipping array. Based on the preamp for Rod Elliott's 100W Guitar Amplifier updated for the year 2026. See the original schematic here. https://sound-au/Project27.htm Modifications are: one op-amp is specified with a different part-number than in the original, slight changes to some of the topology, and changes to part-numbers to obtain more gain and a preferred frequency response curve. Controls Include: Bass, Mid, Treble, Stack Sum, Tone Gain, Fuzz enable switch, Fuzz symmetry switches (two, with 2 settings each), Fuzz Depth, Output Drive, and Output Gain. Range at or above 0 dBV is from 15 Hz to 20 kHz, with emphasis on mids. Suitable for 6/7/8-string guitar or 4/5/6-string bass. Maximum gain = +36.4 dBV (Vo/Vi = 66) @ 400 Hz with all controls at 50%, or +62 dBV (Vo/Vi = 1259) @ 630 Hz with all controls at 100%. This qualifies the circuit to be used as a high-gain overdrive. Power-supply not shown. Requires a regulated dual-polarity supply providing +-9VDC or +-12VDC or +-15VDC at >= 40 mA of current. And while based on a proven design, plus being simulator verified, treat this circuit as experimental in nature. That is, breadboard test it before committing to a soldered build. And house in a grounded metal enclosure.