The Fairchild 660 was the first intelligent automatic volume control limiter. Shortly after its release, the Fairchild 670, a dual-channel version, was introduced. Due to their rarity, Fairchild compressors have become highly sought-after and incredibly valuable, with used Fairchild 660 units selling for over US$20,000 and 670 units fetching between US$30,000 and US$40,000 or more. These compressors are often considered the “holy grail” of outboard gear.
The Fairchild 660 was designed by Rein Narma, who had previously collaborated with Les Paul to build a recording mixer for Paul’s Ampex 8-track system. Les Paul then asked Narma to create a compressor/limiter. Sherman Fairchild, a friend of Les Paul’s, became aware of Narma’s design and decided to license it, subsequently hiring Narma as the chief engineer at Fairchild Recording Equipment Corporation.
The first 10 Fairchild 660 units were built by Narma himself. The first unit was sold to Rudy Van Gelder, who used it to cut lacquer masters for Blue Note and Vox Records. The second went to Olmsted Sound Studios in New York City, and the third was purchased by Mary Ford and Les Paul.
The mono Fairchild 660 and dual-channel 670 are versatile compressors that can operate with a compression ratio ranging from 2:1, with a threshold of 5 dB below normal program level, to a peak limiter with a ratio of 30:1, and a threshold of 10 dB above normal program level. Both units use a single push-pull amplification stage and a high control voltage, which results in a signature sound free of audible thumps, with exceptionally low distortion and noise.
The Fairchild 660 and Fairchild 670 feature a rapid attack time capable of full limiting within 1/10,000 of a second. This fast attack is paired with six variable release timing curves, three of which adjust automatically based on the amount of limiting, making the Fairchild 660 the first compressor/limiter to include automatic variable release time.
The Fairchild 660 has controls for input gain, threshold, and time constant, (while the Fairchild 670 offers the flexibility to be used as two independent limiters or as a vertical and lateral (sum and difference) component limiter).
Abbey Road Studios purchased 12 Fairchild 660s after staff engineer Peter Bown encountered the unit during a visit to Capitol Records in the U.S. These compressors were used extensively in recording sessions for the Beatles, particularly for vocal tracks. Starting in 1966, Geoff Emerick expanded their use, applying the Fairchild 660 to Ringo Starr’s drum tracks, as well as on piano and guitar recordings. Remarkably, as of 2014, Abbey Road still retained 8 of the original 660 units purchased in the 1960s.
