MXR MX-129 Pitch Transposer

The MXR MX-129 Pitch Transposer is a rack-mounted pitch changing unit from the late 1970s, which came with an M-131 display.

Mike Rutherford used the MXR pitch transposer with Genesis. It was primarily as a studio unit for processing the Moog Taurus pedals, at least on the Abacab album and the band's 1983 self-titled album.