These input sockets provide the use of external signals for amplitude (AM)- and pulse width modulation (PWM).

The LEVEL inputs provide amplitude modulation. Modulation of oscillator's level (amplitude) can be provided by any low frequency- or audio signal, such as; LFO, Envelope Generators, Oscillators or any other signal source. If audio signals are used, the resulting waveforms are complex and contain in addition to the carrier
frequency two inharmonic sidebands per spectral component. The sound character is familiar to the results of FM and thus useful for generating of non harmonic sounds and noises.
The PWM inputs of OSC 1 and 2 are hardwired to the outputs of the MIXER described below. The pulse width
of all three oscillators can be modulated by any other signal.