12 flanger

If you’ve ever heard a guitar that sounded like an aeroplane taking off, there was probably a flanger in the signal chain. The humble flange swirls like a metallic phaser with extra whoosh, but its innards lie somewhere between phase and chorus. Flangers split your guitar signal into dry and wet halves, the latter of which features a hint of delay. These delay times are shorter than a chorus at just a few milliseconds.

When the signals are blended back together again, the resultant phase interference causes harmonically ordered gaps or ‘notches’ to appear in the frequency spectrum. The position of the notches is then swept up and down by a low-frequency oscillator (LFO, controlled by the rate knob), which alters the delay time of the wet signal – just like a phaser.

Flangers are often characterised as ‘cold’, but with careful adjustment of rate and depth controls, they can produce very similar effects to chorus, too. However, crank up the resonance dial and you’ll get super-resonant sweeps that are unmistakably flange-like. You can hear it most prominently on Heart’s Barracuda, but a stellar clean example of the effect is The Cult’s She Sells Sanctuary.

the humble flange swirls like a metallic phaser with extra whoosh