distortion

Distortion is the result of any process that alters a sound's waveform and adds new frequency components¹. In guitar gear, it is produced by pushing a signal beyond an amp or pedal's headroom, clipping it with a circuit, or using transistors as imperfect amplifiers². A distortion pedal generates enough gain to push the signal into a non-linear clipping zone, producing a distorted sound at lower levels without relying on the amp also being overdriven³. Compared with overdrive, it is generated by hard-clipping rather than soft-clipping, producing a more compressed and noticeable effect⁴. The resulting sound is often described as crunchy and gritty with lots of sustain, the basic sound of most classic rock, heavy rock, and metal³.