The EMI RS 114 Limiter was a valve-based mono limiter developed by EMI’s Research Department in the mid-1950s. It became a core component of Abbey Road Studios’ equipment lineup, most notably used extensively during the Beatles’ early recording sessions from 1962 to 1964. The EMI RS 114’s unique sonic character played a significant role in shaping the group’s first three albums (Please Please Me, With the Beatles and A Hard Day’s Night) as well as numerous early singles, including She Loves You, Twist and Shout, I Want To Hold Your Hand and And I Love Her.
The EMI RS 114 was introduced as an improved version of EMI’s earlier RS98 limiter. Its development was likely influenced by staff feedback on American Fairchild limiters, particularly those used at Capitol Records. The EMI RS 114 was formally described by EMI as a “limiter amplifier with delay line”, though the delay referred not to an echo effect but to a circuit that slowed the attack time of the limiter. This was achieved via an attack control that allowed the unit to respond more musically to incoming signal transients.
Developed by EMI engineer Mike Bachelor, the EMI RS 114 was originally built in a batch of six units in 1956, with additional units added the following year. The initial set included one for each of the studio control rooms, two for the disc-cutting rooms and one for remote recording. Although originally designed for mastering applications, the RS114 quickly proved valuable on pop sessions. A pair of units was often placed on a mobile rack beside the desk, where engineers such as Norman Smith used them routinely. Smith’s particular fondness for the RS114 led to its widespread use on vocal and guitar parts during key Beatles recordings.
The EMI RS 114 offered several advanced features that remain familiar today. It included stepped input and output level controls in 2dB increments, with an additional -1dB switch for finer adjustments. The attack time was set using a two-position “Operating Time” switch, offering Slow or Fast settings. Release time was adjusted via a six-position “Recovery Time” switch, similar to the preset timing options later seen on the Fairchild. A five-position “Weighting” control tailored the limiter’s response to input signal brightness. The In/Out switch functioned as a bypass, with a third “Balance” setting for internal alignment.
Despite its popularity, the EMI RS 114 was difficult to maintain. It used a complex push-pull valve circuit that required constant balancing. If not correctly calibrated, the limiter behaved unpredictably and introduced audible artefacts. Engineers Malcolm Addey and Stuart Eltham noted that the EMI RS 114 drifted out of alignment easily and described it as unreliable during long sessions. Calibrating the unit involved reading multiple valve voltages, adjusting five internal balance controls and referencing up to fourteen measurement points. This made the RS114 time-consuming to set up and maintain, often requiring visits from EMI’s technical staff during sessions.
Still, the EMI RS 114 was one of the first gain-control devices EMI engineers had access to, and it served its purpose well when few alternatives existed. Though not as refined or stable as the Fairchild, it played a vital role in shaping the sound of many iconic recordings during a pivotal time in music history.
The EMI RS 114 was retired from recording use by mid-1964 and replaced by the Fairchild 660. It remained in use in EMI’s disc-cutting rooms into the late 1960s. Unfortunately, little documentation remains today regarding the EMI RS 114’s exact circuitry or service history.
Features
- INPUT level control: Stepped 2dB knob for precise recallable settings.
- OUTPUT control: Also a 2dB stepped knob, with a “-1dB” switch for in-between steps.
- OPERATING TIME: Switch for Attack setting, either Slow or Fast.
- RECOVERY TIME: Six-position switch for varying release times (likely influenced by Fairchild).
- WEIGHTING: Five-setting control changing response relative to input brightness.
- IN/OUT switch: Bypass function, with a third “Balance” setting for alignment mode.
- The RS114 had two meters, one for gain reduction and the other for “Balancing” (circuit alignment).
- Despite appearances, the RS114 was a mono device.
