The VM901 is a full-function oscillator module. It can be used in the audio range, or as a low-frequency modulation source.
Inputs, Outputs, and Controls
Fixed Voltage Control- Sets the range down five octaves or up six octaves.
Frequency Range- Sets the coarse frequency range to sub-audio or standard audio ranges in standard organ footages. Use the Lo setting when using VM901 as low-frequency modulation source.
Fine Tuning (0/1/2)- Allows continuously variable tuning down (0) or up (2) one octave.
Width Of Pulse Waveform- Sets the width or "duty-cycle" of the rectangular (aka, pulse) wave. It has no effect on any other waveform. Its default setting of 50% produces a perfect square wave, rich in odd-order harmonics. Moving the knob left or right narrows its width as well as the thickness of sound until it almost disappears at its extremes.
Control Inputs- These are 1V/octave exponential inputs. They're used for pitch CV as well as modulating the oscillator frequency. All three jacks are the same and their incoming voltages are summed.
Sine/Saw/Triangular/Pulse volume knobs- These set the volume of each waveform for each respective output jack in the bottom row.
Fixed Level Outputs- These are outputs for the sine, sawtooth, triangular, and pulse waves, respectively. They not affected by the Sine/Saw/Triangular/Pulse knobs and are always at full output level.
Sine/Saw/Triangular/Pulse adjustable outputs- These are outputs for the sine, sawtooth, triangular, and pulse waves, respectively. Their output level is set by the Sine, Sawtooth, Triangular, and Pulse volume knobs.