The MXR Distortion + ("Distortion Plus") is an overdrive pedal originally designed in the 1970s by MXR Innovations. The pedal uses a single opamp and a pair of germanium diodes to ground for clipping in a very simple configuration with only Output and Distortion controls.
This pedal is perhaps best known for its crunchy heavy metal sound that was featured by Randy Rhoads in his work with Ozzy Osbourne. Jerry Garcia of the Grateful Dead used this pedal exclusively for distortion in the late 1970s. Bob Mould of Hüsker Dü also used the Distortion + as part of his trademark guitar sound. Dave Murray of Iron Maiden has used Distortion + since the early 1980s. Thom Yorke ofRadiohead has included the + for many of his signature distortion sounds, using a variety of guitars to achieve various tonal options.