voltage controlled harmonic generator

A voltage controlled harmonic gener- ator is a particularly useful device for music synthesisers as another means to achieve sound synthesis. The circuit presented here was designed to be used with the Elektor Formant music synthesiser, but the idea can be used in many other applications, such as generating harmonics for a guitar etc. Following the true Formant tradition, the circuit utilises a mixer with three inputs having a nominal input sensitivity of 2 V p-p. Once the input level is correct the output signal from IC1 is clipped by RD and D1. The clipping level can be controlled by a voltage fed into the modulation input ECV, from a low frequency oscillator (LEO) for instance. The clipped and unclipped signals are then subtracted by the differential amplifier IC3. The result depends on the level of unclipped signal which is preset by P2. Figure 2 shows 2 3 a 1 7 / 8-521 • 2 examples of the resultant output signal with large (2a) and small (2b) levels of unclipped triangula...