Driving gain into a saturator and lowering its ceiling clips the waveform peaks into distortion

Distortion in a saturator/waveshaper comes from clipping: push the signal hard into the stage by raising input gain, then lower the output level/ceiling so the tops of the waveform are cut off. Removing the peaks flattens the wave toward a squarer shape, which adds harmonics — the perceived ‘distortion’ or grit. In FM8 the operators are routed into the X (saturator) operator; increasing gain and dropping the level clips the peaks. This is the core mechanism behind adding aggression to a Reese: harmonic-rich distortion built by deliberately overdriving then clipping, rather than by an EQ boost. The more the peaks are clipped, the more harmonics and the louder/denser the tone, up to the point it becomes harsh.

Examples

In FM8: feed the operators into X (saturator), raise the gain for volume, then bring the level down so the waveform peaks are cut off — the sound gains distortion. More gain plus a lower ceiling = more clipping = more harmonics.

Assessment

Explain how raising input gain and lowering the output ceiling of a saturator produces distortion, and what happens to the waveform shape and harmonic content as clipping increases.