Audio Alchemy

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During my first 4 years in radio I worked in a studio wired for monaural sound only. Stereo aircheck recording was not feasible with the available equipment. However, in 1985, I used a small “disco” mixer to make stereo mix tapes for personal use. Previously, I experimented with re-routing the left and right outputs of a single turntable to the two mono pre-amps then into program and audition respectively; successfully recording in stereo. This method was cumbersome because the left and right inputs were controlled by two separate knobs on the board (one routed to audition, the other to program.)The studio’s Technics SP-15 turntables audio cords were re-routed from the usual phono pre-amplifiers to the small (cheap) stereo mixer. The diagram above is a speculative idea of what if I had used this set up to record an actual aircheck by adding a microphone(s). Using this type mixer would have been real world challenging due, in part, to its inability to switch on and off monitors and microphone.

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By 2009 I had the ability of digitally isolating the live vocal portions of my original aircheck recordings and carefully synchronizing in stereo music from CD’s and other digital files (mp3, wav, etc.) It was impossible to remove all unwanted mono audio. Some “phasing” between the new stereo and old mono occurred.

With this in mind an alternate wiring path would have been preferable for future “stereo rebuilds”. The simple diagram to the right illustrates an easy method of electrically isolating the DJ microphone from the (mono) music and other prerecorded elements of my shows. The isolated vocal tracks could have been later used to assemble a true stereo mix, either analog or digital.