Sherman Mills Fairchild was the son of Congressman George Winthrop Fairchild, one of the founders of the Computing-Tabulating-Recording Company which later became IBM.
One of the many (around 70) companies that Sherman founded was Fairchild Recording Equipment Corp. in New York.
Sherman had a friend named Bing Crosby (yes, that one) who took delivery of Serial Numbers 001 and 002 of Ampex's first audio tape recorder, the model 200 that had been designed after a German machine made by AEG and sold under the Magnetophon name that was brought back from the war. The Magnetophons had been used to allow Hitler to broadcast from one city while being somewhere else. Bing Crosby didn't like doing "Live" shows and wanted the machines model 200 made by a fairly new company called Ampex that had been founded to manufacture small electric motors that was founded in 1944. In 1948 Bing began to record the first radio shows in the U.S. The show was called "Bing Crosby's Philco Radio Time" that could be edited and played back at a later time for broadcast.
Bing also had a guitar playing friend named Les Paul (yes, that one) who had been experimenting with over dubbing and layering the tracks. Around this time Bing was introduced to a guy named Rein Narma who was born in Estonia and was a refugee from Soviet Russia and had worked for the U.S. Army as a broadcast engineer during the Nuremberg trials. He landed in New York and got a job at Gotham Recording. Les Paul hired Rein to modify his first 8 track machine and build an 8 track console. Les also asked Rein to build a limiter for his recording studio. Sherman Fairchild learned of the limiter design and licensed it and hired Rein as the chief engineer. Rein later left Fairchild and became Vice President of Ampex engineering.
On Friday, January 7, 1927 the president of American Telephone and Telegraph Company, W.S. Gifford made the first ever telephone call across the Atlantic to Sir Evelyn P. Murray of the British Post Office. In the early days of telephone, in order to make a Trans-Atlantic phone call you would call a special operator who would connect you to another office that would "arrange" the call to Europe. You would wait your turn until the operator called you back. The call was then routed by High Frequency (HF) radio. Due to radio propagaion fading, the signal would vary moment by moment.
Your call went out to a large Western Electric transmitter at Deal Beach, N.J. with its antenna aimed in the direction of Europe. (The Receiver was located at Netcong, NJ.) A person sitting at a console would monitor the signal and control the volume manually by turning a knob to compensate for the fading. (The first three minutes of your phone call would cost you $75.)
On May 6, 1930, an engineer named Robert C. Mathes at Bell Telephone labortories was awarded a patent (1,757,729) on a circuit using two triode vacuum tubes used as an electronic volume control. It was a fully balanced design that cancelled even harmonics. A rectified (DC) version of the audio produced a control voltage that, fed back to the gain stage, forced the output of the limiter to be a constant level.
This was essentially the circuit that was modified by Rein to become the Fairchild 660 and 670. The novel thing about the Fairchilds was the use of a power amplifier to drive the control voltage of the gain control amps. This enabled the ultra fast attack that is one of the hallmarks of the Fairchild limiters.