Originally Posted by tkmedia2
I remember seeing AHD, and thought oh boy another audio format! At the time there was....
-ALP/VLP (early to mid 1970's) a 12" double sided disc similar to Laserdisc. Audio Long Play/Video Long Play stored as FM mod out.
-PCM recorders which would record on VHS/Beta tapes and reel to reel.
-PCM recorder that used analog compact audio cassettes.
-DAT prototypes in the early 1980's
-MO (forgot what it was called early 1980)similar to MiniDisc but on CD sized disc. not to be confused with CD-MO of the early 1990's.
-CDP format was Sony's early format of CD, but with a paper ring title area in the hub.
Don't forget TelDec's MiniDisk, which was a 4-inch disc (in a caddy) played with a piezo-electric-based diamond stylus. It was a direct application of thier TeD Videodisc system to digital audio storage - they submitted it to the DAD group as a possible digital audio standard too. It spawned the Teldec Direct Metal Mastering system for CD's.
And do you remember Compusonics? They, ahem, "planned" to introduce a consumer recordable digital audio disc system, that recorded 60 minutes per side on the 5-1/2 inch floppy disk! Later, it turned out that they had NO technology to sell - all thier demo's had been faked with a CD player providing the sound!
Philips ALP 'morphed' pretty quickly into the CD format - and in 1977, Pioneer and MCA were doing experimental work on a 14-bit digital audio disc system - that's why Pioneer's VP-1000 had the "Adaptor" output - just in case they ever actually released a product. It was nice though, because since the "adaptor" jack on the VP-1000 output the entire RF spectrum from the disc, including the raw audio carriers, it could be used as an AC-3 LD player with an AC-3 LD RF demodulator! Talk about future-proof!
Oh, at the DAT group also standardized "S-DAT" (as opposed to R-DAT) - it used the Philips Compact Cassette mechanism with 20-tracks - same sampling rate and bit-depth as DAT. Nothing ever came of it though, but Philips later morphed it into DCC with their PASC coding system.
BTW, I tried to upload a JAES technical paper from 1979 on the TelDec MiniDisk digital audio disc, but I can't get the PDF any smaller than 600k or so, which is too large for the forums. Bummer - it's a fun paper.