'86 Simpson-Clarke Preamp Circuit PUBLIC

Boosting Preamp with 2-Band Tone

Guitar preamp with 2-band tone that can serve as a high-gain clean boost. Based on preamp for a high-power FET stereo amplifier by Leo Simpson and John Clarke, Radio Electronics mag., July 1986, p57. Modifications include addition of an output buffer and part-values changes. The original can be seen here.
https://www.worldradiohistory.com/Archive-Radio-Electronics/80s/1986/Radio-Electronics-1986-07.pdf Controls Include: Drive, Gain, Bass, Treble, and Volume. Range is from < 10 Hz to > 25 kHz, with emphasis on mids. Suitable for 6/7/8-string guitar or 4/5/6-string bass. Maximum gain = +21.4 dBV (Vo/Vi = 11.8) @ 1 kHz with all controls at 50%, or three peaks with all controls at 100%; +59 dBV (Vo/Vi = 891) @ 100 Hz, +40 dBV (Vo/Vi = 100) @ 1 kHz, and +43.4 dBV (Vo/Vi = 148) @ 10 kHz. Power-supply not shown. Requires a regulated dual-polarity DC supply providing +-9VDC or +-12VDC or +-15VDC at >= 40 mA of current. And while based on a proven circuit, plus being simulator verified, treat the circuit as experimental in nature. Breadboard test it before committing to a soldered build.