Single-Battery Preamp 6 PUBLIC

Guitar preamp powered by a single 9V battery, with Bass Boost, Schottky-Diode Fuzz, and 3-Band Fender-Style Tone-Stack.

Guitar preamp powered by a single 9V battery, with 2-stage Bass Boost, shunt-type Schottky-diode fuzz, and 3-band Fender-style tone-stack. Controls Include: Input Attenuation enable switch (Attenuate or Direct), Attenuation control, Input Gain, Bass, Mid, Treble, Drive, Boost Enable switch, Boost Level, Fuzz Enable switch, Fuzz symmetry switches (two with 2 settings each), Fuzz Depth, Output Gain, and Volume. Without Boost, the frequency range is from 25 Hz to > 20 kHz; emphasis on highs, maximum gain +12.7 dBV above 4 kHz, and all controls at 50%. Suitable for 6/7-8-string guitar or 4/5/6-string bass. With Boost, the Boost Level control sets response as follows. Both Gain controls are 50%. Boost Level 25%, range is from 25 Hz to 7.3 kHz, and maximum gain is +14.2 dBV @ 100 Hz. Boost Level 50%, range is from 25 Hz to 8 kHz, and maximum gain is +23.7 dBV @ 100 Hz. Boost Level 75%, range is from 20 Hz to 11 kHz, and maximum gain is +34 dBV @ 100 Hz. Boost Level 100%, range is from 20 Hz to > 20 kHz, and maximum gain is +40 dBV @ 100 Hz. Note: With Boost Level control < 20%, it will attenuate the entire output signal, but > 20%, it will boost entire signal, in addition to boosting lows exponentially as the control is turned clockwise. Recommended Boost Level settings: 25% min. to 75% max. The circuit is meant for stomp-box projects. But the battery can be replaced by a regulated single-polarity DC supply providing +9VDC or +12VDC or +15VDC at >= 40 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.