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Is the Optical Cable Dying? (cnet.com)
Geoffrey Morrison from CNET explains how the optical cable is "dying a very slow death": The official term for optical audio cable is "Toslink," short for Toshiba Link. Developed in the early '80s to connect their CD players to their receivers, it was a red laser optical version of the Sony/Phillips "Digital Interconnect Format" aka S/PDIF standard. You've seen standard S/PDIF connections a bunch too; they're often called "coax digital." Optical had certain benefits over copper cables, but they were also more fragile, and for a long time, more expensive. Though glass cables were available, for even more money, most optical cables were made from cheap plastic. This limited their range to in-room use, primarily. Through the '90s and 2000's, the optical cable was near-ubiquitous: The easiest way to get Dolby Digital and DTS from your cable/satellite box, TiVo, or DVD player to your receiver. Even in the early days of HDMI, right next to it would be the lowly optical cable, ready in case someone's receiver didn't accept HDMI. But now more and more gear are dropping optical. It's gone completely on the latest Roku and Apple TV 4K, for example. It's also disappeared from many smaller TVs, though it lingers on in larger ones, a potentially redundant backup to HDMI with ARC. The reason for this? Soundbars...
Digital optical is utterly inferior to HDMI Audio. It only supports 2 channels uncompressed, anything other than that. 2.1, 5.1, 7.1 is compressed.
From Wikipedia: https://en.wikipedia.org/wiki/...
Unlike HDMI, TOSLINK does not have the bandwidth to carry the lossless versions of Dolby TrueHD, DTS-HD Master Audio, or more than two channels of PCM audio.
HDMI supports uncompressed audio, 2.1, 5.1, 7.1 or even greater.
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Erm the coax connector is digital, in fact the exact same digital data as optical.
Coax noise affecting the digital signal? Not Gonna happen.
Coax cables can cause ground loops, which wont do anything to the digital parts of your equipment. But analogue parts like amplifiers may be affected by it, mostly by causing a hum noise.
Digital optical is utterly inferior to HDMI Audio. It only supports 2 channels uncompressed, anything other than that. 2.1, 5.1, 7.1 is compressed.
More so than you are letting on with that information. For many people the desire to carry Dolby TrueHD or some other stuff like that is not interesting. But even then the digital optical is inferior to any other interface. Put a scope on a typical TOSLINK input and you'll see nasty looking barely square waves. This wouldn't be significant if equipment didn't then use the edges of these to derive the clock signal causing it to jitter back and forth.
The only benefit it provided over its cabled brethren was isolation but that can also be achieved with a simple and far better performing pulse transformer.
The standard never got a foothold in professional audio.
S/PDIF has a "copyright bit" that consumer audio devices (including cheap audio cards) heed. Once the bit is set, the devices will not create digital media from the stream or let them be read into a computer. A copy created from material with the bit reset will have the bit set: no further copies are possible.
So we are already in MAFIAA crapola land here.