These three are modulation effects. They all make a copy of your signal, change it slightly, keep that change moving slowly up and down, and mix it back with the original. The differences are in how much they change the copy.
How each one works
- Chorus delays the copy a little (tens of milliseconds) and gently wobbles that delay, which makes its pitch drift slightly sharp and flat. Mixed with your dry signal, it sounds like two guitarists playing the same part: wide, shimmering, a little watery.
- Flanger uses a much shorter delay, only a few milliseconds, and sweeps it. At that range the two signals cancel at some frequencies and reinforce others, and the sweep makes those peaks move. Add feedback and you get the famous jet-plane whoosh.
- Phaser uses no delay at all. It shifts the phase of the copy with a chain of filters and sweeps that shift. The result is a softer, rounder swirl than a flanger, with fewer and smoother notches.
| Effect | By ear | Classic pedal |
|---|---|---|
| Chorus | Doubled, shimmering, wide | Boss CE-2 |
| Flanger | Metallic, jet whoosh | Electro-Harmonix Electric Mistress |
| Phaser | Swirling, liquid, vocal | MXR Phase 90 |
The knobs
- Rate (Speed): how fast the effect sweeps. Slow sounds lush; fast sounds wobbly, close to vibrato.
- Depth: how far it sweeps. More depth means a more obvious effect.
- Feedback (Regen, Resonance): feeds the output back in. On flangers and phasers it makes the sweep sharper and more resonant.
- Mix (Level, Blend): how much of the effected copy you hear.
The Phase 90 has a single Speed knob, and many simple choruses have only Rate and Depth.
Typical uses
- Chorus: clean arpeggios and chords, 80s pop and new wave. Andy Summers' sound with The Police is the usual reference. Start with Rate at 10 o'clock and Depth at noon.
- Flanger: occasional dramatic moments, riff intros and psychedelic textures. Use it as a special effect, not a constant.
- Phaser: funk rhythm, slow-swirling leads, and adding movement to a crunchy riff. Eddie Van Halen's use of the Phase 90 is widely documented. Try a slow Rate, around 9 o'clock.
These usually go after your drives. In front of a drive they get louder and more aggressive, which some players like on phasers. Too much Depth on any of them makes your tuning sound off, so if chords sound sour, back it down.