Auto-wah

A filter pedal whose sweep is driven by how hard you play instead of by a foot treadle.

An envelope follower watches the incoming level and uses it to move a filter's cutoff, so a light touch leaves the sound dark and a firm attack opens it up with a quack. That makes the effect respond to technique rather than to a planned move, and it is why the same lick can sound static or lively depending on the right hand. Controls are usually sensitivity, plus a range or resonance control that sets how far the filter travels.

Example: a funk line played with short, snappy chords makes an envelope filter snap open on every strum, which is the classic clavinet-style sound.

Auto-wah

See also