The Eventide Model H949 Harmonizer is a combination digital delay line, pitch changer, and all-round special effects unit. The TIME REVERSAL feature is entirely new. When used with a variable-speed tape recorder, the Harmonizer is capable of shortening or lengthening a piece of program material to fit a given time slot, without altering the pitch.
The MXR rack line of gear line began with 2-space rack units such as the MXR Model 113 Digital Delay, MXR Model 124 Dual 15-Band Graphic EQ, MXR Model 126 Flanger/Doubler, and the MXR Model 129 Pitch Transposer.
The Eventide Model H910 Harmonizer was developed by Eventide in 1974. It was the world’s very first digital effects processor. It combined ‘de-glitched’ pitch change with delay and feedback. It could be controlled by a keyboard remote control to instantly shift pitch in half steps.