This video offers a short audio demo of the capabilities of the Oakley Overdrive module – a design that is available both as a synth DIY project or pre-assembled.
The Oakley Overdrive-II features two different waveform modifiers, designed to produce a wide range of overdriven and distortion sounds.
The first waveform modifier is a classic overdrive circuit which can produce a sound that is familiar to many guitarists. The circuit has two basic modes selected by a switch. Hard is a raucous distortion type effect useful for grunging up your signal. Soft is a more subtle effect and produces a clean sounding overdriven amp sound.
The second waveform modifier is a harmonic multiplier. This part of the module produces additional harmonics by folding over the input signal so that the tops and bottoms of the waveform are forced the wrong way. This produces strident changes in tone that are dependant on the signal level. Up to two stages of symmetrical folding are available and at the output there is a soft clipping circuit to prevent excessive folding at extreme input levels.