Tom Morello’s MXR Phase 90

This is one of the longest-standing pedals on Tom Morello’s pedalboard – he had it since the early 90. However, the pedal only gets used once in all the songs he wrote, which is at the very beginning of “Killing in the Name”, during the first four bars.

The MXR Phase 90 is a phaser guitar effects pedal that creates a swirling, sweeping sound by modulating the phase of the guitar signal. It has a single control knob that adjusts the rate of the phase-shifting effect. Turning the knob clockwise increases the speed and intensity of the effect while turning it counterclockwise slows it down.