The OSC1 from Future Sound Systems presents a voltage-controlled analogue oscillator with a few features unexpected of a basic oscillator, with a particular focus on covering all bases of signal modulation. Once triangle, sinusoidal and pulse waveforms are derived from its sawtooth core, each waveform is passed through a VCA. The outputs from these VCAs are then summed at the Mix output, which can be switched between 2- and 4-quadrant-multiplication modes. These two QM modes allow for a plethora of amplitude modulation effects to be achieved. Level controls for each waveform dictate both static level, but also depth of modulation through careful design of the control summation. Each individual waveform output is taken pre-VCA for maximum patching flexibility.
Shape modulation of the triangular, sinusoidal and pulse waveforms is also available. Both the triangular and sinusoidal waveshapes can be skewed forward or backward into ramp-like shapes, whilst shaping the pulse wave gives standard pulsewidth modulation.
Frequency modulation is available in both Linear and Exponential modes. The OSC1 also tracks to 1V/Octave over four octaves in its audible (HF) range, but can also be used as a low frequency oscillator in LF mode.
A Sync input allows for the OSC1 to be reset by an external signal. A rising edge will reset the sawtooth wave to its peak, from which it descends. The Inject input, meanwhile, allows for external signals to interfere with the sawtooth core. This allows for intermodulation-type effects to be produced, and opens new realms of chaotic oscillations.