KORG PA4X 76 - Manual (Page 640)

636| Effects for the Sounds
b, f: Saturation [%]
With higher settings of this value, the waveform will change at high gain
levels, tending to cause distortion. Lower settings of this value will produce
linear response.
Mic/Pre Amp - Saturation
In
Out
Saturation = 0
Saturation = 50
Saturation = 100
Bias = 0
c: Tube1 Bias
This expresses the effect that changes in vacuum tube bias have on the dis-
tortion of the waveform. Higher settings of this value will produce distortion
even at low gain levels. Since this will also change the overtone structure,
you can use it to control the tonal character.
In
Out
Satulation = 50
Bias = 0
Bias = 50
Bias = 100
Mic/Pre Amp - Bias
d: Tube1 Phase
With the Wet Invert setting, the phase of the signal will be inverted between
stage 1 and stage 2. Since “Bias” is applied to the inverted signal in stage 2,
this will change the tonal character.