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Comment by selectodude | Hacker News Reader

I think at this point it’s called vinyl.

Vinyl is far from open source CD due to limitations of phisical format and the fact that good vinyl contains specifically mastered for vinyl with those limitations taken into account.

You can still easily buy Bluray player and open source your discs with ARM (not CPU/SoCs, different one)

If you're referring to the RIAA equalization curve[1] that is completely open and well defined.

[1] https://en.wikipedia.org/wiki/RIAA_equalization

Like all analog formats, vinyl has a non-linear response. Things like total amplitude and frequency content affect noise and distortion when reproduced. Another factor is that it's a constant angular velocity medium, so the response is different at the beginning than the end. These are factors that a good mastering engineer takes into account.

This occurs in the digital world as well. When we went to DVDs, the studios had encoders/authoring engineers, who tweaked compression parameters per scene, as compression is another non-linear process. For example, they might apply a small amount of blur on a dark scene where film grain trips up the compression.

Eta: Apple provides the exact pipeline [1] they use for their services so the sound engineer can listen to the output and adjust.

[1] https://www.apple.com/apple-music/apple-digital-masters/

Point I'm making: vinyl is a lossy format and not just lossy, it degrades with plays even if your turntable is super-duper calibrated. It even degrades just by sitting in a sleave if environmental conditions aren't close to perfect.

I really hope not, there isn't a single redeeming quality to vinyls from any practical point of view.

The big album art?

I'll give it that, though the size in general is a downside for more people than it is a benefit.

Even the discs themselves can be works of art now. Even though vinyl discs are less practical than CDs they're a subjectively fun art experience.

to play a record, i don't need a computer or any electronics created after, say, 1960 or so. that's a nice benefit :)

Better yet, you don't need any components in the supply chain that weren't well within the means of people 100 years ago. Vinyls and Edison cylinders will outlive every CD ever made.

That's a fun statement. I think we already had vacuum tubes and other foundational components that would in theory have allowed someone to build a CD player a 100 years ago or very close to that. If they would have had the knowledge.

For starters, CDs are not very dense, you can see the data with a microscope: http://www.pmonta.com/compact-disc-microscopy.html

In addition to the circuitry, I was also assuming that the laser would pose a difficulty.

It doesn't really require a coherent light source, although that does allow further miniaturization.

I think it would be fair to allow a hypothetical 1920s CD player to occupy most of a room. I'd be interested to see exactly how hard it would be to produce such a thing using the available technology of the era, though I'm still somewhat skeptical regarding the complexity and precision required of the laser motor (which unlike a vinyl needle needs to be controlled manually, rather than just following a groove mechanically) and the spindle motor (which needs to accelerate precisely depending on the laser's distance from the center, unlike a record which revolves at a constant rate).

CD players came out in 80s, so one could say I don't need electronics made after the 80s to play those. Do those 20 years matter that much? I doubt it.

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