Phaser (effect)

A phaser is an electronic sound processor used to filter a signal by creating a series of peaks and troughs in the frequency spectrum.

The position of the peaks and troughs of the waveform being affected is typically modulated by an internal low-frequency oscillator so that they vary over time, creating a sweeping effect.

When signals from the two paths are mixed, the frequencies that are out of phase will cancel each other out, creating the phaser's characteristic notches.

Traditional electronic phasers use a series of variable all-pass phase-shift networks which alter the phases of the different frequency components in the signal.

The term was often used to refer to the original tape flanging effect heard on many psychedelic records of the late 1960s, notably "Itchycoo Park" (1967) by the Small Faces.

[4] It was widely employed in the studio and in live settings by artists such as Led Zeppelin and Todd Rundgren.

From 1974, Steve Hackett of Genesis, in the Selling England by the Pound (1973) studio album and tour, used the MXR Phase 90 for his Les Pauls, and from The Lamb Lies Down On Broadway (1974) album and tour, used the phase filter section in his Electronic Music Studios Synthi Hi-Fli.

[9] In the late 1970s and 1980s, Eddie Van Halen often used the MXR Phase 90 as part of his signal chain,[10] for example in the instrumental "Eruption" and on the song "Atomic Punk".

Examples can be heard in Billy Joel's "Just The Way You Are", Styx's "Babe", and Jean Michel Jarre's Oxygène (1976) on which he used an EHX Small Stone phaser extensively.

Daft Punk helped to re-popularize the effect in the 21st century, utilizing it on a number of tracks on their Discovery album in 2001.