ArcSyn User Manual: Drive Types
Clipping with a rounded edge modelled after the transfer function of silicon diodes.
Clipping with a 100% sharp, artificial square edge.
"Overdrive" distortion modelled on the response of a tube ('valve' in the UK).
A sine function. This will convert an input triangle waveform to a sine wave if the levels are right, thereby making the signal softer instead of harsher. Higher levels will be clipped, creating a soft clipping effect.
A sine function without clipping. Higher input levels will cause the sine shape to fold in on itself creating strong "ripples" with an FM-like tonal quality.
A sine function (as above) with a much lower level, creating a softer effect.
A combination of overdrive and clipping which will tend to turn any input signal into a square waveform. The harshest DRIVE effect ArcSyn has but still with a slightly rounded edge.
Reduces the input signal to a series of quantised steps, otherwise known as bit reduction. At low levels (small steps) this will be nearly inaudible, at high levels (large steps) it will be much more extreme and can result in the signal cutting out altogether if it isn't high enough to reach the first step level.