The MXR Phase 90, model M101, is one of the pedals that shaped the rock sound alongside legendary amps and guitars. The first pedal released by MXR in 1974, it has stood the test of time without losing its identity: an orange box, an analog circuit, and modulation that is both smooth and musical. Vintage versions are highly sought after, but the spirit of the original remains alive in the current version, designed for more reliable modern use.
The Phase 90 is suitable for both beginner guitarists (immediate setting, impossible to "misadjust") and seasoned musicians who want an expressive phaser that's easy to integrate into a pedalboard. It excels in rock and hard rock to thicken rhythm parts or highlight leads, but it's equally credible in blues to animate a clean tone, in funk to add movement to chicken-picking, or in alternative for more psychedelic textures. In the studio or live, it's a reliable choice: plug in, set the speed, and it works.
The Speed knob adjusts the phaser's sweep rate: slow for a wide, enveloping movement, fast for a more nervous and hypnotic feel, close to a Leslie-type rotary effect. The regeneration rate is fixed, chosen to optimize intensity and keep a musical output without getting lost in settings. An ON/OFF LED provides clear status indication on stage.
The Phase 90 is renowned for its round modulation, with a notch and frequency rise that create a very organic "whirling" effect. It can remain subtle at slow speeds by adding depth to a clean tone, or become more pronounced at higher speeds for soaring passages and catchy transitions. With an already driven amp, it also has the talent to smooth the attack slightly and add a sense of thickness that helps transition from rhythm to solo without changing the amp settings.