Korg prologue Owner's Manual page 28

VPM
This engine is a VPM (Variable Phase Modulation) oscillator that was developed es-
pecially for this instrument. The engine features a simple structure with one carrier
and one modulator, but allows you to create a wide range of sounds.
Sixteen oscillator types are available for this VPM oscillator.
mod attack
mod decay
shape mod int.
eg
phase mod
feedback
OCTAVE switch
The pitch of the VPM oscillator can be set in octaves.
TYPE knob
This selects the oscillator type to use.
The name of the oscillator type will be indicated on the MULTI ENGINE display.
Sin1: Modulated sine wave carrier basic type.
Sin2: Sine wave carrier and a modulator with self-feedback.
Sin3: Sine wave carrier with modulator 3 harmonics higher.
Sin4: Sine wave carrier with modulator 5 harmonics higher.
Saw1 Modulated sawtooth carrier basic type.
Saw2: Sine carrier based pseudo-sawtooth type.
Squ1: Modulated square wave carrier basic type.
Squ2: Sine carrier based pseudo-square wave type.
Fat1: Second subharmonic modulator with self-feedback and driven carrier output.
Fat2: Half subharmonic modulator with self-feedback and driven carrier output.
Air1: Noise modulated sine wave carrier.
Air2: Sine wave carrier modulated by both noise and a sine wave.
Decay1: Type with decaying modulation amount.
Relative offsets to the internal EG decay time (see block diagram) can
TIP
be added via the PROGRAM EDIT mode "Button 7 (MULTI ENGINE)"
(p.50). For the last 4 types, setting Shape Mod Int to -100% will disable
completely the impact of the EG.
Decay2: Type with strong decaying modulation amount.
Creep, Throat: Experimental type with complex and evolving modulations.
pitch
pitch ratio
mod. depth (index)
carrier
phase
noise depth
noise
[2', 4', 8', 16']
[Sin1...Throat]
drive output
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