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Comment by mikece | Hacker News Reader

I thought there was something in the early 2000s that used a laser (an array of them, actually) to map the grooves on a vinyl (or wax) record with perfect precision that allowed for the virtual audio processing of the record in higher quality than any physical stylus or pre-amp system could deliver. (There was also the side-benefit that the reading process didn't involve physical wear on the record or cylinder to optically record the grooves.)

Also, not being a vinyl expert, I would like to learn more about the different types of stylus and how that affects playback... does anyone have any links?

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Optical turntables have major issues with dust and dirt. The records need to be extensively cleaned prior to being played [1], even for unplayed "virgin" vinyl. 78rpm (shellac) records are older than vinyl records, and tend to have more dust / dirt, so would require a lot of cleaning prior to archiving.

Although the more expensive of the optical turntables (the LT-master) has 78rpm capabilities, such capabilities are optional even on this high-end version.

I think it's basically down to costs - the costs of cleaning each record (I know they're cleaned already, but the process may need to be more involved to remove all dust), along with the tens-of-thousands for the player, probably don't make this economical on the scale the Internet Archive are looking for.

[1] https://en.wikipedia.org/wiki/Laser_turntable#Performance

Here's what our digitization expert, George Blood, has to say: LPs are soft and played with a very small diamond. 78s are made from shellac which is hard and abrasive. Originally they were played with steel needles at 10x the tracking weight used by our modern equipment. They also use a much larger diamond with 5-10x the surface area. The tracking force is spread over a larger area than vinyl playback. The contact pressure is less than 10% of vinyl playback.

There is such a laser record player, which costs $15k [1] and can only play black vinyl records [2].

[1] https://diffuser.fm/laser-turntable/ [2] https://www.theabsolutesound.com/articles/elp-lt-1lrc-laser-...

I suspect you really in fact do want to record the audio as it was intended to be played back. With the mass of the tone arm, the tracking and such as the tone arm swings closer to the inner radius of the disc, the RIAA equalization....

Seems if you strictly are extracting the topography of the record ... good for printing a new one, but would require all kinds of simulation to playback accurately?

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