Behind the J37 Tape

The original J37 was a 1" 4-track machine designed by Swiss recording pioneer Will Studer. Released in the early 1960s, the J37 was Studer’s first multi-track machine and a true technological breakthrough, embodying versatility, functionality and simplicity in what was then a state-of-the-art machine.

In 1965, Abbey Road Studios purchased four new J37s, which were used on almost every recording until 8-track machines were introduced to Abbey Road Studios in 1969. Prior to the J37, Abbey Road used a 4-track Telefunken tape machine, which was a large and cumbersome contraption that required a separate machine room. This caused communication issues between the producer and tape operator, which complicated and prolonged the recording process. In contrast, the J37 was small enough to be placed directly in the control room, opening up the creative potential for multi-track recording.

Following the rigorous testing process required by EMI of all equipment used at Abbey Road, four modifications were made to the J37s. Firstly, wheels were added to make the units easily transportable. Secondly, a Bulgin 3-prong socket was installed to enable the connection of an oscillator, which was handy when using the machine at non-standard speeds. The 4-track Telefunken machine used before the J37 stored the tape with the oxide facing outwards, so a reverse switch was added to the back of the J37 to enable easy playback of these tapes. Finally, the EQ preset switch, which originally offered the option of NAB (American) or CCIR (European) broadcast curves, was locked to CCIR, the EMI-approved curve.

The frequency response of the machine was outstanding, reaching 18 kHz at the high end EQ which, along with its 52 vacuum tubes, enabled it to produce a rich spectrum of tonal colors. Part of the distinctive sound of recordings made at Abbey Road Studios during the 60s and 70s was down to the use of special tape formulas, developed by EMI for exclusive use in its studios: EMI TAPE 888 (early ‘60s), EMI TAPE 811 (mid ‘60s) and EMI TAPE 815 (early ‘70s). Each possessed its own unique frequency response and harmonic distortion behavior, which lent a distinctive timbre to the recordings for which they were used.

While the J37 was used on many famous recordings, it is perhaps best known for its innovative use on The Beatles’ Sgt. Pepper’s Lonely Hearts Club Band. Producer George Martin utilized the machine not only for recording but also as a creative production tool, bouncing tracks between two J37s and creating layer upon layer of sound to achieve groundbreaking sonic textures.