Split-Supply Preamp 4 PUBLIC

Split-Supply Guitar Preamp w. 3-Band Tone and 3-Voiced Fuzz.

Split-supply guitar preamp with Fender-style 3-band tone-stack and 3-voiced shunt-type diode fuzz matrix. Controls Include: Input Attenuation enable switch (Attenuate or Direct), Attenuation control, Fuzz enable switch, Fuzz 1,2,3 enable switches, Fuzz 1,2,2 symmetry switches, Fuzz Depth, Drive, Bass, Mid, Treble, Stack-Sum, Gain, and Volume. Fuzz voices are from separately selectable Schottky diode, standard silicon diode, and LED arrays. Frequency range is from 40 Hz to 25 kHz with all controls at 50%. Suitable for 6/7-string guitar or 4-string bass (not recommended for 8-string guitar or 5/6-string bass). Maximum gain = +23 dBV @ 1 kHz with all controls 50%, and up to twice that with all controls at 100%. With no fuzz, preamp can serve as a Clean Boost with 3-band tone. The circuit can be for stomp-box or rackmount applications. The batteries can be replaced by a regulated dual-polarity DC supply providing +-9VDC or +-12VDC or +-15VDC at >= 20 mA of current. [Note: Higher supply voltage results in lower op-amp noise.] And though simulator verified, treat the circuit as experimental. Breadboard test it before soldering.