Wah-wah pedal

Wah-wah pedal (Dunlop Crybaby 535q) on electric guitar with distortion.

A wah-wah pedal, or simply wah pedal, is a type of effects pedal designed for electric guitar that alters the timbre of the input signal to create a distinctive sound, mimicking the human voice saying the onomatopoeic name "wah-wah". The pedal sweeps a band-pass filter up and down in frequency to create a spectral glide. The wah-wah effect originated in the 1920s, with trumpet or trombone players finding they could produce an expressive crying tone by moving a mute in, and out of the instrument's bell. This was later simulated with electronic circuitry for the electric guitar when the wah-wah pedal was invented. It is controlled by movement of the player's foot on a rocking pedal connected to a potentiometer. Wah-wah effects may be used without moving the treadle as a fixed filter to alter an instrument’s timbre (known as a “cocked-wah”^[1]), or to create a "wacka-wacka" funk-styled rhythm for rhythm guitar playing.^[2]

An auto-wah pedal uses an envelope follower to control the filter instead of a potentiometer.

^ Lynham, Alex (16 April 2021). "The 4 unsung hero effects pedals and 3 great ways you can use them". Music Radar. Future Publishing Limited Quay House. Retrieved 25 February 2022. Turning on a wah pedal and 'parking' it at a position in its sweep is known as 'cocking' the wah.
^ Du Noyer, Paul (2003). The Illustrated Encyclopedia of Music (1st ed.). Fulham, London: Flame Tree Publishing. p. 375. ISBN 1-904041-96-5.

[1] Lynham, Alex (16 April 2021). "The 4 unsung hero effects pedals and 3 great ways you can use them". Music Radar. Future Publishing Limited Quay House. Retrieved 25 February 2022. Turning on a wah pedal and 'parking' it at a position in its sweep is known as 'cocking' the wah.

[Music-2] Du Noyer, Paul (2003). The Illustrated Encyclopedia of Music (1st ed.). Fulham, London: Flame Tree Publishing. p. 375. ISBN 1-904041-96-5.

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