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Comment by habosa | Hacker News Reader

Vinyl is one of those old-school technologies that seems like it's from the future. Somehow we turned sound into a disk. You can see and feel the sound and then a tiny needle will reproduce the original sound just by touching the disk. And in very high quality!

Blows me away every time I think about it. And we could have kept going: https://en.m.wikipedia.org/wiki/Capacitance_Electronic_Disc

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Could have kept going...

The CED offers one hour of VHS quality per side that rapidly degenerates. I own a sizeable collection of them, and while sorta neat, it’s also sorta terrible.

The vinyl offers quality superior to most consumer tape equipment rivaled only by 11 ips reel to reel. CED had no quality advantages, decays rapidly and is non recordable. It was a non-starter.

The fact is that CED was in the works since the 50s when it may have had a short successful life, but RCA couldn’t get off their ass. In fact CED was the last consumer product ever released by RCA. (The RCA of today is just a badge on various crap after being divested by Thomson Consumer Electronics)

Also even though CED uses a stylus, the similarities end there. You can literally run your nail in a phono groove and hear the sound. It is a literal imprint of the sound wave. Video cannot be encoded in such a straightforward manner, NTSC and PAL are not trivially. Also the CED is not vibrating the stylus. Rather the stylus sits on ridges and the signal is depth encoded (therefore varying the capacitance, hence the name). It is much closer to a crappy laser disc in operation (which also encodes in analog.. not digital)

An old boss of mine worked on that beast! From the sounds of it, it barely worked in the lab. He told a story of getting so frustrated one day that he literally shoved his ‘scope off the back of the bench in frustration and walked out for the day. In his opintion, it is a good thing that it is dead and buried.

I have dismantled the players. Truly a marvel of electromechanical design. So many hand soldered and assembled parts. It is incredible they made it work mass produced. Too bad it was 20 years too late.

We kinda did keep going, except we put the grooves onto foil as little dots, and read them with a laser. Also, the whole thing is encased in polycarbonate.

You need a computer of some sort to decode that, whereas vinyl _is_ engraved vibrations.

Engraved vibrations that have been transformed with the RIAA curve so that they will fit. It can be played raw, but most of the bass is missing. This is what pre-amps are for.

The frequency-dependent amplification performed by RIAA eq is in fact a simple analog computer!

It's possible that you could get sound out of a CD with just a shift register and maybe a PLL circut to sync up the boundries of the PCM codes, and a way to skip over the error correction data (which would be harder to make dedicated hardware for but probably not impossible.) The audio data on CDs is still just uncompressed PCM which really doesn't need a computer.

Stands to reason it wouldn't have been impossible to make an analogue medium using similar technologies. Imagine the refraction angle varying continuously and some wide-range pickup that converts to electricity.

_why_, of course, is a different question

Laserdisc was an analog implementation of that technology. Eventually it also carried digital audio a la CD but the video and the original audio encoding were analog.

Are you sure that's not this RCA CED thing they're talking about?

I'll second it - LaserDisc was an analog medium - not digital. CED was analog also, but used a "stylus" to pick up capacitance changes from the "groove" depth. There's plenty of information out there on both processes; very interesting to see, you should check it out...

You might enjoy: https://www.youtube.com/watch?v=8D0Aan4myoE

Very cool! Thanks for sharing.

Many years ago at a ham swap meet (used to be a thing pre-E-bay) a guy was selling an old record lathe that had come out (years earlier) of one of radio network affiliate stations in SF. It was used to record the network feed so that it could be time shifted to West Coast time. It had been hooked up to a leased telephone line and the live shows from the East Coast were cut into vinyl, and later played back over the air.

Obviously, tape recording evenually obsoleted that equipment.

Luckily, I had earlier that morning burned through my ham radio budget getting a HAL ST-6000 RTTY modem and associated goodies, so I was saved from the fate of adding that particular boat anchor to my collection.

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