I got a Snazzy FX “Dual Multiplier” the other day, and thought it might be a good opportunity to talk about audio multiplication and the difference between AM synthesis and ring modulation.
Both AM synthesis and RM can be accomplished by multiplying a waveform (the “carrier”) by another waveform in the audible range You don’t need an analog multiplier to do this! You can do this in whatever synthesis environment you’re working in–Pd, Max/MSP, Kyma, Reaktor. All you have to do is multiply your signals, being mindful of whether the signals are unipolar (0 to 1) or bipolar (-1 to 1).
More on modulation synthesis: