The Binson Echorec was a major part of Pink Floyd’s sound, especially in the early days. A spinning magnetic drum recorded sound on one side and then played the sound as that part of the drum rotated to the other side, producing an echo delay or reverb effect depending on the dials and switches. Syd Barrett used it for psychedelic echo effects on songs such as “Interstellar Overdrive”, David Gilmour continued from there and developed his own style. Richard Wright and Roger Waters used it as well.
The Echorec was part of David Gilmour’s guitar rig up through the Animals album and tour. As one can imagine from the spinning drum mechanism very closely surrounded by recording and playback heads, the Binson Echorec was a delicate device, not built to handle the rigors of touring. Although he was considered the expert among the band and crew in calibrating it, he became tired of having to do so and after the Animals tour started using newer digital technology. Although no longer using the Echorec, delay continued to be a Gilmour signature component in songs such as “Another Brick in the Wall” and “Run Like Hell”.
Notable uses of the Echorec on bass include “One of These Days”, where Waters played quarter notes which were repeated by the Echorec to form the eighth notes between them, and “Echoes”, where Waters used a steel slide on the strings of the bass and fed the sound through the Echorec to create the ambient background noises during the song’s freeform section.