VCO3 can operate as either an audio range oscillator (as per VCO 1 & 2) or a Low Frequency Oscillator (LFO).
When VCO3 is used in audio range mode, this knob adjusts the tuning of oscillator 3 across a range of four octaves. Similar to Oscillators 1 & 2, the outer ring of the knob controls coarse tune and the inner part of the knob controls fine tune. You can also use right-click on the mouse (or Control-Click) to move the outer ring in quantised pitch increments.
When VCO3 is used as an LFO, this knob adjusts the frequency or speed at which the LFO modulates. As per VCO 1 & 2, the outer ring of the knob controls coarse tune and the inner part of the knob controls fine tune. Additionally, when used as an LFO (in non-sync mode) you can use right-click on the mouse (or Control-Click) to move the outer ring in quantised pitch increments.
Selects between a Sawtooth, Sine or a Square Wave. The square wave is a fixed 50% square and its width cannot be changed.
This determines the modulation source whenever the SEM front panel modulation switches are set to VCO3. By Selecting WAV the modulation source will be the Waveform chosen by the above VCO3 WAVE SHAPE Switch (Saw, Sine or Square), or Pink Noise.
You can modulate (or sweep) VCO3 by the shape of either Envelope 1 or Envelope 2. In the centre position (NIL) no modulation will occur.
When in the OFF position, VCO3 behaves in the same way as VCO 1 & VCO 2 audio rate oscillators. When switched into LFO mode (ON) VCO 3 will become a second Low Frequency Oscillator (LFO). With SYNC selected VCO becomes an LFO synchronised to the tempo of your host with rates of between 16 beats and 1/32 of a beat.
With VCO3 in LFO RATE mode, and in the ON position, the selected modulation waveform will retrigger and reset the waveform phase every time a note-on event occurs.
In LFO RATE mode, this applies a degree of ramp-in or delay before the LFO Rate waveform takes effect. When the LFO RATE SWITCH is set to SYNC the Intro Time is synchronised to the host tempo with settings between a minimum of 1/32 (Demi-semi-quaver) and 16/4 (Four Bars).