Since its opening in 1931, Abbey Road Studios have been known as a bastion of recording excellence and innovation. EMI's Recording Engineer Development Department (REDD) was established in 1955 by Abbey Road Studios technical engineer Lenn Page to address the needs of the then-burgeoning stereophonic format. Within a year, the team's efforts had led to the production of the REDD.1 console, Abbey Road Studios' first dedicated stereo mixing system, which consisted of a REDD.8 mixer and a rack that housed its amplifiers and other components.
In 1957, its successor was created: The REDD.17, designed by Peter Burkowitz of EMI's German affiliate, was one of the first desks to conform to the design we've come to expect from mixing consoles, with EQ on each of its eight channels. Like the REDD.1 before it, the REDD.17 was a mono/stereo board.
Later the following year, in response to the growing popularity of the four track recording format, the third in the series, the REDD.37, was released. Both the REDD.17 and REDD.37 were powered exclusively by legendary Siemens V72 valve amplifiers and, in the case of the REDD.37, at least 31 of them!
The REDD.37 was followed by the REDD.51, which used newer REDD.47 amps, and offered lower distortion and more headroom than the V72s. Originally created in 1959, it was not until 1963 that the .51 found its way to Abbey Road Studios. Four of the .51 desks were ultimately built; by 1968, they were slowly phased out by EMI's next generation of solid-state eight and sixteen track consoles, the TG series.