Lexicon Delta-T 101 (1971)
The first commercial digital audio product on earth - and it carried Gotham Audio's name on the front and Lexicon's on the back.
Overview
The story starts at MIT, not in a studio. Dr. Francis Lee built a digital delay unit for heartbeat monitoring. A teaching assistant named Barry Blesser suggested running audio through it instead. Blesser would later design the EMT 250, the first practical digital reverb. The experiment produced a 100ms audio delay line, which was state-of-the-art for that time. The box that carried it to market was the Delta-T 101.
The late Steve Temmer of New York's Gotham Audio heard about the delay line and commissioned 50 units. He wanted them for two jobs: overcoming live sound propagation delays and serving as a pre-delay for plate reverbs. So the first Delta-T 101s went out with "Gotham Audio" on the front nameplate and "Lexicon" on the back. Collectors still check that first, because it tells you which side of the arrangement a given unit shipped from. DB Magazine (July 1971, p.9) called the new Gotham Audio Delay System "fair warning to all that the age of the computer has arrived," and warned that the successful recording engineer would soon need at least a nodding acquaintance with the new technology.
The specs are modest. The original unit offered a 10kHz bandwidth and a 60dB signal-to-noise ratio. That is less than stellar, but remarkable for its time. Sixty dB of SNR is a hiss floor you would never tolerate in a modern rig. On a plate reverb pre-delay or a live-sound fill, though, it was a revelation because nothing mechanical was in the signal path at all. The 100ms delay line was the whole point. It was enough to nudge a signal in time, and not enough for the looping and chorusing tricks that came later.
Lexicon clearly knew the noise figure was a problem. Its answer was the Delta-T 102, sold under the Lexicon name, which pushed the noise down to an acceptable -90 dB and helped convince the industry that digital audio was a viable proposition. A 101 is the proof of concept, not the finished product.
The Lexicon/Gotham Delta-T 101 is recognized as the first commercial digital audio product. EQ Magazine (February 2000, p.36) opens its look at the 960L by noting it is "almost hard to imagine" that Lexicon introduced the Delta-T 101 delay line - the first commercially marketed digital delay - back in 1971. Every Lexicon delay and reverb that followed, from the 224 family through the 480L, traces its lineage to this box.
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