Delay is a sound changing module that plays the sound source more than once at different times. The delay plays copies of the original sound source at later times. The classic delay effect sounds like an echo (echo, echo). We can use delay to create a sense of ambience, texture, and even rhythm. This simple effect is endless in variation.
A simple delay plays a second copy of the original sound source at a later time. A feedback delay doesn't just play back a straight copy of the sound source. A feedback delay plays the combination of the original sound source and the previous copies as well. A multitap delay can trigger more than one copy, often within the rhythm of the music.
Delay effects come in a variety of styles, but have a few common parameters. One parameter is the number of iterations that will play back. Tempo sync is a common feature as well, which lines up the delayed playback to the rhythm of the music. Each iteration has its own parameters, usually duration, gain, and filtering.
Delay has a relationship to flanger, phaser, and chorus. These modules play back copies of the original sound. The main difference is the duration of the delay. Flanger and phaser have delays of 1-20ms, chorus is usually 20-80ms, while the delay effect is longer than 80ms.