MXR Distortion +:The MXR Distortion Plus is an overdrive pedal that uses a single opamp and a pair of germanium diodes in a very simple circuit. The D+ was the pedal of choice for Bob Mould from Hüsker Dü, as well as Randy Rhoads, early Iron Maiden, & Chavez. This is a script logo version from 1976. More info here.