4 ms·

It sounds antithetical to the analog nature of vinyl, but has anyone experimented with digital audio on vinyl?

by teeray 4y ago

empyrrhicist 4y ago
Most modern vinyl records have digital processing somewhere in their source. I do remember recently reading about video games on vinyl also.
crazygringo 4y ago
I assume you mean actual binary encoding into the vinyl? Now that's a hacker idea if I ever heard one. I assume the way to do it would be to use a modem the same way the internet operated over dial-up. Listening to the vinyl would sound the same as when you accidentally picked up a phone on the same line, a static-y kind of squeal. It does make me wonder what the maximum practical bitrate would be -- more than phone lines with their severely limited frequency range, that's for sure. Could it handle CD-quality FLAC audio? It also makes me wonder how you'd manage records wearing out. What type of distortion occurs, and how might that affect how you'd spread bits over the spectrum, or would it affect which error correction code you'd use?
- dweymouth 4y ago
  > Could it handle CD-quality FLAC audio? I doubt it, since CD-quality audio is already objectively better (for human hearing) than analog audio on LPs. The only thing LPs are better at, sound quality wise, is extension into the ultrasonic range of 20-30+ kHz (which we can't hear anyway) but the SNR and distortion metrics are much worse in the ultrasonic band than the audible range. I'm not sure if this is a named principle, but it seems intuitively obvious to me that on any particular encoding medium (magnetic tape, vinyl groove, etc.), you can encode "more" data in an analog way than digital, since with digital encoding you need to be able to make distinct symbols onto the medium, and represent any signal fluctuation with a series of such symbols; whereas with analog encoding a tiny fluctuation in what's recorded to the medium can correspond to a tiny fluctuation in the signal. Of course the tradeoff is that digital data is much more immune to distortion from imperfections in the medium. If the same track width and pit sizes on CDs were used to encode audio in an analog way like LaserDisc does video (the continuous distance between pits being modulated by the signal), no doubt it could encode well into the ultrasonic range and surround audio channels via modulating them into different frequency bands. But it would have its own characteristic "surface noise" and "pops and clicks" just like vinyl.
  - crazygringo 4y ago
    > it seems intuitively obvious to me... you can encode "more" data in an analog way than digital It doesn't seem obvious to me, because I'm not talking about encoding distinct symbols into the medium. I'm talking about using the entire available frequency range to encode digital information the way a modem does. And I'm talking about using lossless compression as well. And as you say, if an LP can encode ultrasonic information, that opens up all sorts of extra space for information that is useless in analog. It may very well be the case that an LP couldn't record CD-quality audio, but I do very much wonder what kind of bitrate would actually be achievable. A dial-up modem is 56 kbps, using the frequency range 300 hZ to 3.3 kHz. CD audio is 1,411 kbps, but vinyl frequency range is from 7 hZ to 50 kHz, which is 16x wider than a dial-up modem. And you can pack much more data into higher frequencies. So on the face of it, digital CD-quality audio seems like it might be very much achievable in theory on vinyl. But again, when you account for error correction and degradation and particularly distortion, I wonder if you could actually get it reliably in practice.
    - dweymouth 4y ago
      Hmm that's a good point, that you can use the ultrasonic bandwidth of the LP, which is useless for analog audio, to increase the bitrate. I'd say it's a bit generous to give an LP a bandwidth of 50 kHz, especially in the inner tracks though. I think what I was getting at would apply where the bandwidth of the analog signal you want to encode is as wide as the bandwidth of your media though. Take compact cassettes, let's say they have a bandwidth of 18 kHz and a dynamic range of 60 dB. If you want to encode an arbitrary audio signal with a bandwidth of 18 kHz and with 60 dB dynamic range, you could only do that in the usual analog way. But if you wanted to encode a digital telephone signal (say at 8 kHz bandwidth, 30 dB dynamic range) maybe you could use the 18 kHz cassette bandwidth to encode that signal digitally.
  - IIAOPSW 4y ago
    And if you could truly do analog manipulations of infinite precision real-valued quantities, you could beat a Turing machine. Analog precision eventually hits the so-called Heisenberg limit, below which further information does not exist.
- CocaKoala 4y ago
  You can indeed encode digital data onto a vinyl and then play it back meaningfully to a computer - http://boginjr.com/it/sw/dev/vinyl-boot/ http://boginjr.com/it/sw/dev/vinyl-boot/ is somebody making a vinyl boot disk and using it to boot DOS.
  - crazygringo 4y ago
    Ah ha, exactly! Wow. What's next, encoding a ZIP file onto a wax cylinder?
- roddylindsay 4y ago
  DTS is a lossy codec that can encode multiple audio channels into normal stereo audio. The encoded waveform sounds exactly like a dialup modem.
marcodiego 4y ago
Yes. Not necessarily digital audio, but digital data: https://en.wikipedia.org/wiki/Flexi_disc https://en.wikipedia.org/wiki/Flexi_disc
IIAOPSW 4y ago
I'm vaguely aware of a band that had a track titled something like 8600 baud that was basically instructions to decode a secret message. Not quite what you wanted, but it proves the principle of digital-on-vinyl is possible. Another similar demo is a long forgotten digital VHS format, which wrote binary video data to an old fashion VHS tape. IIRC it had some outrageous capacity for number of hours of video it could store. So very doable though storage density and bandrate would need to be calculated.

It sounds antithetical to the analog nature of vinyl, but has anyone experimented with digital audio on vinyl?

by teeray 4y ago

It sounds antithetical to the analog nature of vinyl, but has anyone experimented with digital audio on vinyl?

Most modern vinyl records have digital processing somewhere in their source. I do remember recently reading about video games on vinyl also.

crazygringo 4y ago

I assume you mean actual binary encoding into the vinyl? Now that's a hacker idea if I ever heard one. I assume the way to do it would be to use a modem the same way the internet operated over dial-up. Listening to the vinyl would sound the same as when you accidentally picked up a phone on the same line, a static-y kind of squeal. It does make me wonder what the maximum practical bitrate would be -- more than phone lines with their severely limited frequency range, that's for sure. Could it handle CD-quality FLAC audio? It also makes me wonder how you'd manage records wearing out. What type of distortion occurs, and how might that affect how you'd spread bits over the spectrum, or would it affect which error correction code you'd use?

dweymouth 4y ago
> Could it handle CD-quality FLAC audio? I doubt it, since CD-quality audio is already objectively better (for human hearing) than analog audio on LPs. The only thing LPs are better at, sound quality wise, is extension into the ultrasonic range of 20-30+ kHz (which we can't hear anyway) but the SNR and distortion metrics are much worse in the ultrasonic band than the audible range. I'm not sure if this is a named principle, but it seems intuitively obvious to me that on any particular encoding medium (magnetic tape, vinyl groove, etc.), you can encode "more" data in an analog way than digital, since with digital encoding you need to be able to make distinct symbols onto the medium, and represent any signal fluctuation with a series of such symbols; whereas with analog encoding a tiny fluctuation in what's recorded to the medium can correspond to a tiny fluctuation in the signal. Of course the tradeoff is that digital data is much more immune to distortion from imperfections in the medium. If the same track width and pit sizes on CDs were used to encode audio in an analog way like LaserDisc does video (the continuous distance between pits being modulated by the signal), no doubt it could encode well into the ultrasonic range and surround audio channels via modulating them into different frequency bands. But it would have its own characteristic "surface noise" and "pops and clicks" just like vinyl.
- crazygringo 4y ago
  > it seems intuitively obvious to me... you can encode "more" data in an analog way than digital It doesn't seem obvious to me, because I'm not talking about encoding distinct symbols into the medium. I'm talking about using the entire available frequency range to encode digital information the way a modem does. And I'm talking about using lossless compression as well. And as you say, if an LP can encode ultrasonic information, that opens up all sorts of extra space for information that is useless in analog. It may very well be the case that an LP couldn't record CD-quality audio, but I do very much wonder what kind of bitrate would actually be achievable. A dial-up modem is 56 kbps, using the frequency range 300 hZ to 3.3 kHz. CD audio is 1,411 kbps, but vinyl frequency range is from 7 hZ to 50 kHz, which is 16x wider than a dial-up modem. And you can pack much more data into higher frequencies. So on the face of it, digital CD-quality audio seems like it might be very much achievable in theory on vinyl. But again, when you account for error correction and degradation and particularly distortion, I wonder if you could actually get it reliably in practice.
  - dweymouth 4y ago
    Hmm that's a good point, that you can use the ultrasonic bandwidth of the LP, which is useless for analog audio, to increase the bitrate. I'd say it's a bit generous to give an LP a bandwidth of 50 kHz, especially in the inner tracks though. I think what I was getting at would apply where the bandwidth of the analog signal you want to encode is as wide as the bandwidth of your media though. Take compact cassettes, let's say they have a bandwidth of 18 kHz and a dynamic range of 60 dB. If you want to encode an arbitrary audio signal with a bandwidth of 18 kHz and with 60 dB dynamic range, you could only do that in the usual analog way. But if you wanted to encode a digital telephone signal (say at 8 kHz bandwidth, 30 dB dynamic range) maybe you could use the 18 kHz cassette bandwidth to encode that signal digitally.
- IIAOPSW 4y ago
  And if you could truly do analog manipulations of infinite precision real-valued quantities, you could beat a Turing machine. Analog precision eventually hits the so-called Heisenberg limit, below which further information does not exist.
CocaKoala 4y ago
You can indeed encode digital data onto a vinyl and then play it back meaningfully to a computer - http://boginjr.com/it/sw/dev/vinyl-boot/ http://boginjr.com/it/sw/dev/vinyl-boot/ is somebody making a vinyl boot disk and using it to boot DOS.
- crazygringo 4y ago
  Ah ha, exactly! Wow. What's next, encoding a ZIP file onto a wax cylinder?
roddylindsay 4y ago
DTS is a lossy codec that can encode multiple audio channels into normal stereo audio. The encoded waveform sounds exactly like a dialup modem.

marcodiego 4y ago

Yes. Not necessarily digital audio, but digital data: https://en.wikipedia.org/wiki/Flexi_disc https://en.wikipedia.org/wiki/Flexi_disc

IIAOPSW 4y ago

I'm vaguely aware of a band that had a track titled something like 8600 baud that was basically instructions to decode a secret message. Not quite what you wanted, but it proves the principle of digital-on-vinyl is possible. Another similar demo is a long forgotten digital VHS format, which wrote binary video data to an old fashion VHS tape. IIRC it had some outrageous capacity for number of hours of video it could store. So very doable though storage density and bandrate would need to be calculated.