Uh... did you know this existed?
Yeah, did you understand that? It's a rack unit that records 644kbs audio to a VHS tape. I would give up one of my toes for one of these. Any information regarding where one of these units might be aquired would be greatly appreciated. Check out this period review.
The dbx Model 700 Digital Audio Processor was a professional audio ADC/DAC combination unit, which digitized a stereo analog audio input into a bitstream, which was then encoded and encapsulated in an analog composite video signal, for recording to tape using a VCR as a transport. Unlike other similar pieces of equipment like the Sony PCM-F1, the Model 700 used a technique called Companded Predictive Delta Modulation, rather than the now-common pulse-code modulation.