Find out how channel strips evolved from the clunky mixing desks of the '50s and 60s and where they are today.
If anyone could be considered the father of the channel strip, it would be Bill Putnam Sr., founder of Universal Audio in the 1950s. Universal Audio was also responsible for a number of signal processing devices that remain studio standards to this day, such as the 1176LN and LA-2A compressor/limiters, and UA 610 preamp. Prior to the days of the channel strip as found in recording consoles, mixers were built using separate components. One of UA’s claims to fame was to be the first to make the 610 Modular Amplifier (channel strip) for mixers, which comprised a preamp, equalizer, three program outputs, and an echo send with an independent level control. Keep in mind that there were no faders as we know them today, and the equalizer was just 2-band shelving EQ (±6dB at 70Hz and 7kHz).
Back in those days, record labels owned most of the big studios, and mixers were all custom-made. For example, the legendary EMI TG12345 mixing console, which was used on numerous classic recordings such as The Beatles' Abbey Road and Pink Floyd's Dark Side of the Moon, was custom-built by EMI Research Labs from a design brief submitted by engineers at Abbey Road Studios. The TG12345 was never sold commercially. In the studios of the day, an engineer was responsible for creating a block diagram, gain chart, and then have a custom metal panel machined to house the components. Engineers also had to pay careful attention to matching the impedances of components or the signal passing between them could be subject to loss of high-frequency response, noise, distortion, or all of the above. From there, it was wiring and testing until a viable mixer emerged.
So, while Bill Putnam’s revolutionary 610 plug-in modules may have laid the groundwork for the modern modular recording console, UA’s mixers were also never commercially available. Approximately 25 “one-offs” were built, including one for Ray Charles and another for Frank Sinatra. It was a little-known company called Electrodyne that gave us the channel strip and console format we take for granted today. Electrodyne was the first to take all the separate components including mic preamp, line amplifier, controller, equalizer, router, and attenuator, and combine them into one “input module,” as they called it. They also pioneered the “active combining network,” which eliminated the need to match impedances. This gave rise to the channel strip that we take for granted today.
With all that going for them, you may be wondering why Electrodyne faded into obscurity. In the early days of large-format recording console design, there were three major players: Neve, API, and Electrodyne, (which later became Quad Eight). Had Electrodyne been a little wiser about handling their finances, it might have been Neve and API that became the unknowns. Electrodyne/Quad Eight consoles are reputed to have offered equal (though some say better) sound quality at one-tenth the price. In fact, Pink Floyd’s The Wall and Boston’s “More Than A Feeling” were mixed on Quad Eight consoles.
There are a number of modern channel strips available now, which often offer a microphone preamplifer, EQ and some form of compression or limiting, all in one unit. For example, the Universal Audio LA-610 Mk II Recording Channel is an updated version of Bill Putnam’s channel strip that captured the sound of many of the world’s most revered recordings. It pairs two of their legendary products - the 610 Tube Preamplifier and the LA-2A optical compressor, in one rack module. Want to add a channel strip to your recording studio? Browse the extensive selection of channel strips at Musician’s Friend.