This Cwejman VCO-2RM is fully functional and in great condition.
The Oscillators are the main sound sources of the instrument. VC0-2RM is equipped with seven waveforms, LFO mode, sync and waveform outputs are routed to a DC coupled ring modulator (RM). The oscillator's frequency is controlled by COARSE, TUNE knobs and FM inputs. TUNE finetunes the oscillators (± 6 semitones).
Frequency modulation (leveled FM1, FM2 and FM3 ) determinates the intensity of frequency modulation and/or pitch control. All FM inputs are carefully calibrated for 1Volt/octave sensitivity. Frequency modulation, by an audio signal, creates so called "side-bands" that consist of sum and difference of signals frequencies.
These additional frequencies do mostly have a non harmonic sound. Modulation, by low periodic waveforms, such as LFO or envelope generator creates momentary pitch shift of modulated oscillator common named vibrato (by LFO) or pitch bend (by envelope generator).
SYNC means that sync'ed oscillators frequency is tracked by the frequency of controlling oscillator;
OSC2's frequency is syncronized to OSC1's frequency. When the tuned frequency of sync-ed oscillator has the same or multiple of frequency of controlling oscillator then sync-ed oscillators waveform has no or very little "glitch" which results in a sync-ed smooth waveform (sinus waveform). The sync-ed waveforms (with additional FM modulation) are perfect for cutting edge lead sound and hard, funky basses.
PULSE WIDTH % adjusts the pulse width of the pulse wave from 5% to 95%.
WAVEFORM selects the waveform or a mix of waveforms from an oscillator. PULSE WIDTH control works also on the waveform mixes where the pulse wave is included.
Ring modulator (RM) is a classic audio effect device and due to the non harmonic character of the output signal, very useful to create metallic timbres such as bells, sweeping whistles and percussive sounds and tremolo effects (modulated by low periodic signal like a LFO). Two input signals are pre-patched to OSC1 and OSC2 outputs. Using the inputs X and Y, any other external signal can be routed directly into the ring modulator. As modulation source the ring modulator can produce a huge amount of complex waveforms both in the low and audio frequency range.