Released in 1951

EMI RS56 Universal Tone Control

The EMI RS56, or UTC (Universal Tone Control), was a semi-parametric equaliser developed by EMI in 1951 for disc cutting. It gained legendary status at Abbey Road, especially during Beatles sessions, thanks to its flexible three-band EQ and stepped controls. Nicknamed the “Curve Bender,” it was eventually replaced by the TG12412 in the 1970s but remains one of EMI’s most iconic designs.

Released in 1956

EMI RS 114 Limiter

The EMI RS114 Limiter was a valve-based mono limiter developed in the 1950s and used extensively at Abbey Road Studios, especially on Beatles recordings from 1962 to 1964. Known for its distinctive attack and recovery controls, it helped shape the sound of the group’s early work. Though technically complex and prone to drift, it was one of the first gain-control devices available to EMI engineers.

Released in 1960

EMI / Altec RS 124 Compressor

The Altec RS 124 was a custom-modified Altec 436B compressor created by EMI engineers and used extensively on Beatles recordings. Favoured for its smooth compression and warm tone, it shaped bass, guitars, and mix busses throughout their career. Unique EMI modifications made it a completely different unit from the original Altec, and original RS 124s are now extremely rare.