So here's my latest acquisition which, despite being straight from the mid-1980s, still feels like it's coming from the future (to me at least)
This is a Sony PCM-501ES "Digital (PCM) Audio Processor". (The case got a bit bent during shipping which is why it needs a floppy for support.)
What does it do? It converts analog audio that is fed into it to digital PCM-encoded audio... but offers no built-in storage. PCM audio needs lots of space (e.g. 16-bit 44.1 kHz stereo audio is ≈10 MB/min) , so where could you
affordably store several hours of it in the mid-1980s... or, for that matter, as early as the late 1970s, when the first consumer devices of this kind showed up?
- Audio tape? ROFL... nope.
- DAT? Not yet invented.
- Hard drive? Too expensive for the kind of capacity you'd need (hundreds of MBs per hour).
- Recordable CD? Not yet invented.
But what about...
video tape? Like, good ol' Betamax or VHS? Bingo!
This box outputs the converted PCM audio as a black-and-white composite video feed (no audio at all!) you can then record using a standard, off-the-shelf VCR.
This is a screenshot I took when it was doing its magic with
Suzanne Vega's Luka (because that's the first track on the first CD I grabbed, not for some more esoteric reason):
(The feed might seem blurrier than it actually is because I simply took a screenshot while it was running rather than capturing a still frame.)
For playback, you just connect the VCR's video output to the box's video input, hook up the box's audio outputs to your amplifier and off you go. Your very own DIY D.A.T. (Digital Audio Tape)... long before DAT! This, actually, is exactly how the PCM audio for mastering the earliest CDs was recorded, albeit using higher-end U-matic VCRs, not that consumer Betamax or VHS nonsense
