MXR Distortion +

The MXR Distortion + ("Distortion Plus") is a distortion pedal originally designed in the 1970s by MXR Innovations.

An original MXR Innovations distortion plus pedal from 1979, block logo, without LED and battery-only operation (no AC Adapter).

MXR Distortion + on a guitar pedalboard. Distortion + is the yellow unit on front of the pedalboard.

The pedal uses a single op-amp and a pair of germanium diodes to ground (parallel-push) for clipping in a very simple configuration with only Output and Distortion controls, no tone control; the pedal uses no discrete transistors. Turning up the Distortion control increases the amount of distortion and at the same time boosts the treble in the signal.[1]

The pedal's crunchy heavy metal sound was featured by Randy Rhoads in his work with Ozzy Osbourne.[2] Jerry Garcia of the Grateful Dead used this pedal exclusively for distortion in the late 1970s.[2] Bob Mould of Hüsker Dü also used the Distortion + as part of his trademark guitar sound.[3] Dave Murray of Iron Maiden has used Distortion + since the early 1980s.[4] Steve Wynn (musician) used it on the first couple Dream Syndicate albums. Thom Yorke of Radiohead has included the Distortion + for many of his signature distortion sounds, using a variety of guitars to achieve various tonal options. Rowland S. Howard (The Birthday Party/These Immortal Souls/Crime & the City Solution/Solo albums) also used this pedal across his career. Though typically not much of a pedal user, guitarist Slash has talked about using the Distortion + in his early guitar days to help define his tone.[5]