Dimensions: Multi-Wave Distortion PUBLIC

Multiple Waveform Distortion Circuit for Electric Guitar

A multiple waveform distortion circuit for electric guitar. Involves the mixing of sine-waves (original input signal), square-waves (converted from input signal), triangle-waves (converted from the square-waves), and sawtooth-waves (converted from the square-waves). Controls Include: Gain, Clean Drive, Clean Level, Sense (sensitivity), Square-Wave, Triangle-Wave, Sawtooth-Wave, and Volume. There are no tone controls. This circuit should have an external tone-control circuit on its input or output, or both. Frequency Range is 30 Hz to 10 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.] The Sine-wave signal is the input signal, which is boosted by 4 stages of clean gain. Square-waves at the same frequency are converted from the input signal using a Comparator circuit (IC3d). Triangle-waves and Sawtooth-waves are converted from the square-waves using an Integrator circuit (IC3c) and Differentiator circuit (IC3b), respectively. These four signals have separate level controls and are mixed in a summing-amp (IC3a) at the output. The ICs were chosen to ensure clean operation of the op-amps, though some distortion and/or fuzz is inherent to the non-sinusoidal waveforms, and the input signal will inherently include some distortion and noise that cannot be eliminated, which therefore gets amplified within the clean signal. If overdriven op-amp distortion is desired, in addition to the multiple waveform sound, keep IC1 and IC3 as specified and substitute only IC2. For JFET distortion, use a TL082CP. For MOSFET distortion, use an OPA2156IDR. Or for BJT distortion close to that of a 12AX7 preamp tube, use an NJM5532M (the Japanese version of the NE5532N). However, an increase in noise will accompany each such substitution. Listening tests while breadboarding will indicate if noise will be a mitigating factor, if making any such substitution. A special regulated dual-polarity DC power-supply is required, providing +-5VDC at >= 100 mA of current. Do not use a +-9VDC or higher supply voltage. And though simulator verified, treat the circuit as experimental. Thoroughly breadboard test it before committing to a soldered build. And, as usual, house it in a grounded metal enclosure to prevent EMF interference.