MOSFET Bass-Fuzz w. 6-Band Filtering PUBLIC

MOSFET Bass-Fuzz with 6-Band Filtering

MOSFET bass fuzz with 6-band filtering. Uses one dual FET-input op-amp IC, one dual CMOS op-amp IC, one hex non-inverting buffer IC (uses MOSFETs internally), and two dual depletion-mode MOSFET ICs. Controls Include: Input Gain, Drive, Direct Gain, Direct Send, Bass, MId-Bass, Low-Mid, MId, High-Mid, Treble, Fuzz enable switch, Fuzz symmetry switches, Fuzz Depth, MOS Gain, MOS Send, Output Gain, and Volume. Here, the FET-input op-amp is used to send a clean input signal to the buffer array and to a Direct Gain Stage in parallel with the buffers. The buffers and Direct Gain Stage can both be overdriven; the buffers giving MOSFET fuzz and the Direct Gain Stage giving CMOS distortion. The signals from the buffers sum in the other clean FET-input op-amp, whose output is itself mixed with the Direct signal in the Output Stage, likewise able to be overdriven to provide even more CMOS distortion. The D-MOS (depletion-mode MOSFET) transistors are wired to work like diodes and are used in a shunt-type hard-clipping array (from the Direct signal path to ground), but which can be switches ON or OFF by an enable switch. The buffers are configured as high-pass filters with different low cutoff frequencies. The filters emphasize highs but the op-amps emphasize lows. Yet, the buffers are mainly for overdriving, not necessarily for tone-control, with their differences in low corners for voicing, not mere tone shaping. Consequently, an external tone-control of some kind should be used at the input or output of this circuit, or both. Power-supply not shown. Requires a dual-polarity DC supply providing +-9VDC at >= 100 mA of current. And though simulator verified, treat the circuit as experimental in nature. Breadboard test before committing to a soldered build.