Phaser

The Phaser effect has a selectable number of Notches (frequency regions that are attenuated) that can be moved through the frequency spectrum slowly. Traditional stomp-box type of phaser used with electric guitars typically have two notches, expensive studio devices have a higher number of notches. The Phaser effect is particularly suited for electric piano and electric guitar.

Phaser window

Frequency controls the tonal character of the effect.
Range determines the distance the notches move. High values can lead to noticeable pitch shifts.
Speed controls the speed used to move the notches.
Depth controls how deep the notches are (the deeper the notches, the more intense the effect).
The Stereo button can be used to create a stereo effect by moving the left and right channel notches in opposite directions.