MXR · Modulation

MXR Phase 100 Settings Guide

The MXR Phase 100 is a 4-stage and 8-stage phaser — a step up from the Phase 90's single 4-stage circuit. The Script/Block switch selects between a more open, complex sweep (script) and a more intense modern character (block). At 8-stage mode, the Phase 100 produces a lush, more pronounced phasing than the Phase 90, generating more notches in the frequency spectrum for a more dramatic effect. Jimmy Page used a Phase 100 on Led Zeppelin's third album.

Used by: Jimmy Page, Eddie Van Halen

The best MXR Phase 100 settings start with: Speed at 4/10. Adjust from there based on your amp, guitar, and room volume. For Classic Rock (4-stage): Speed 3/10.

What Each Control Does

Speed
Slow
Fast
Modulation / sweep speed

Recommended Starting Settings

Safe starting positions for any style. Adjust from here based on your amp and room.

4
Speed

All values on a 0–10 scale. These are starting points — fine-tune by ear.

Settings by Genre

Classic Rock (4-stage)
Speed3

Slow Speed in 4-stage mode — the Phase 100 in 4-stage mode at slow Speed is comparable to the Phase 90 at similar settings. A subtle, warm sweep adds movement to clean or overdriven guitar without the obvious modulation character of faster settings. Jimmy Page's acoustic guitar work on Led Zeppelin III used phasing at these settings.

Funk (8-stage)
Speed5

Moderate Speed in 8-stage mode — the 8-stage circuit produces a more pronounced, complex phase sweep with more frequency notches than the 4-stage. At moderate speed this creates a rich, swirling modulation that suits funk rhythm where the phase sweep creates rhythmic movement in strummed chords.

Psychedelic (8-stage)
Speed8

Fast Speed in 8-stage mode — the intense, rapid phase sweep at Speed 8 with 8 stages produces an almost vibrato-like effect at the peak rate. An aggressive modulation effect suited to psychedelic or experimental playing where the phaser becomes a primary texture tool rather than a subtle effect.

Blues-Rock (4-stage)
Speed2

Very slow Speed in 4-stage mode — the gentle, almost imperceptible sweep at Speed 2 adds subtle movement to blues-rock rhythm chord work. The modulation is present but doesn't call attention to itself — a studio-quality technique for adding depth to repeated chord passages.

Artist Settings

Documented settings used by professional guitarists on this unit.

Speed3

Page used the Phase 100 on Led Zeppelin's third album (1970) for the phasing effects on acoustic and electric guitar parts. His approach was typically slow Speed in 4-stage mode for a gentle, warm sweep rather than the dramatic effect of maximum Speed.

Speed4

EVH used phasing (primarily Phase 90) through his early career — the Phase 100 appears on some bootleg recordings. His approach was moderate Speed for the swirling chorus-phaser texture on clean arpeggiated chord work.

Also in Our Rig Database

Guitarists who feature this gear in their documented rig — explore their full setup.

Tips & Common Mistakes

  • The 4-stage/8-stage switch (if present on your model — some vintage Phase 100s had this, some didn't) is the most significant control. 4-stage produces 2 notches in the frequency spectrum; 8-stage produces 4 notches for a more complex, lush sweep. Start in 4-stage mode and switch to 8-stage when you want more dramatic modulation.
  • Phasing traditionally appears before reverb and delay in the signal chain but after compression and overdrive. Running phaser into a reverb produces a classic 1970s production sound where the phased signal fills the reverb space.

MXR Phase 100 — Common Questions

Best starting settings for MXR Phase 100: Speed at 4/10. Adjust from there based on your guitar, room, and playing style.

For Classic Rock (4-stage): Speed 3/10. Slow Speed in 4-stage mode — the Phase 100 in 4-stage mode at slow Speed is comparable to the Phase 90 at similar settings. A subtle, warm sweep adds movement to clean or overdriven guitar without the obvious modulation character of faster settings. Jimmy Page's acoustic guitar work on Led Zeppelin III used phasing at these settings.

For Funk (8-stage): Speed 5/10. Moderate Speed in 8-stage mode — the 8-stage circuit produces a more pronounced, complex phase sweep with more frequency notches than the 4-stage. At moderate speed this creates a rich, swirling modulation that suits funk rhythm where the phase sweep creates rhythmic movement in strummed chords.

Speed: Modulation / sweep speed (Slow to Fast)

The 4-stage/8-stage switch (if present on your model — some vintage Phase 100s had this, some didn't) is the most significant control. 4-stage produces 2 notches in the frequency spectrum; 8-stage produces 4 notches for a more complex, lush sweep. Start in 4-stage mode and switch to 8-stage when you want more dramatic modulation. Phasing traditionally appears before reverb and delay in the signal chain but after compression and overdrive. Running phaser into a reverb produces a classic 1970s production sound where the phased signal fills the reverb space.

Jimmy Page settings: Speed 3/10. Page used the Phase 100 on Led Zeppelin's third album (1970) for the phasing effects on acoustic and electric guitar parts. His approach was typically slow Speed in 4-stage mode for a gentle, warm sweep rather than the dramatic effect of maximum Speed.

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