Modulation effects combine multiple audio signals in order to create sounds with unusual tonal properties. Some modulation effects mix modulate an instruments audio signal with a signal generated by the effect called a carrier wave. Other modulation effects split an instruments audio signal in two, altering one portion of the signal and mixing it with the unaltered portion.
Distortion effects create warm, gritty and fuzzy sounds by clipping an instruments audio signal, which distorts the shape of its wave form and adds overtones. Distortion effects are sometimes called gain effects, as distorted guitar sounds were first achieved by increasing the electric power supply (i.e. gain) to tube amplifiers.
Modulation effects combine multiple audio signals in order to create sounds with unusual tonal properties. Some modulation effects mix (modulate) an instruments audio signal with a signal generated by the effect called a carrier wave. Other modulation effects split an instruments audio signal in two, altering one portion of the signal and mixing it with the unaltered portion.
A tremolo effect produces a slight, rapid variation in the volume of a note or chord. The tremolo effect should not be confused with the misleadingly-named tremolo bar, a device on a guitar bridge that creates a vibrato or pitch-bending effect. In transistorized effects, a tremolo is produced by mixing an instruments audio signal with a sub-audible carrier wave in such a way that generates amplitude variations in the sound wave.