MXR Phase 90

The MXR Phase 90 is a legendary analog phaser pedal that has shaped guitar tones since 1974. This compact stompbox is one of the most influential modulation effects in music history, delivering the signature swooshing phase sound heard on countless recordings from Van Halen to modern indie rock.

The Phase 90's beauty lies in its single-knob simplicity. One Speed control is all you get, and all you need. Turn it slow for lush, swirling textures beneath your playing. Crank it fast for vibrato-like wobble and psychedelic intensity. The four-stage phaser circuit produces two frequency notches that sweep through the audio spectrum, creating the characteristic jet-like swoosh.

Circuit Heritage

The original 1974 "script logo" Phase 90 used hand-matched JFET transistors, producing a subtler, more organic sweep. The later "block logo" version introduced a feedback resistor that added more intensity and a sharper, more pronounced effect. The current M101 reissue captures the block logo character with modern reliability and true bypass switching.

Why One Knob Works

Most phasers offer depth, feedback, and stage controls. The Phase 90 proves that constraints breed creativity. The fixed depth and feedback are voiced perfectly for guitar — deep enough to hear clearly, subtle enough to leave on all the time. Eddie Van Halen famously kept his Phase 90 on for entire albums, using it as a tone thickener rather than an obvious effect.

Who Is This For?

• Classic rock and hard rock players chasing the Van Halen Phase 90 tone
• Funk and R&B guitarists wanting smooth, liquid modulation
• Minimalists who appreciate single-knob simplicity
• Pedalboard builders who need a compact, reliable phaser that just works
• Keyboardists looking for classic analog phase on Rhodes and organ sounds