Digital cables: a lack of understanding

eyediabinary cropped

There’s a new article about digital cables which is directly relevant to my post a couple of weeks back – it even features the “eye diagram” I referred to.

It purports to ‘debunk’ the idea that “bits are bits”, but in reality it does nothing of the sort. It starts off with a question that it fails to answer and doesn’t come back to again:

Asynchronous USB audio to the rescue?

The remainder of the article is about isochronous USB and seeks to suggest that it is not just about getting all the data through intact, but that there are issues with timing, jitter and noise. Judging by the comments that follow, the readership is entirely unaware that it is a non sequitur they have been reading.

There is a strange little “Note” placed halfway down in tiny lettering that says

Do not confuse ‘asynchronous USB’ with ‘Isochronous,’ an asynchronous USB system still uses Isochronous mode to transfer audio.

I am not quite sure what that is supposed to mean, but again it seems to be an appeal to the false idea that it is beyond the wit of man to deliver digital audio data without it being corrupted, or affected by timing. As I have said before, if this were true, then systems such as TIDAL could not work: the data has come through thousands of miles of cheap cable not even made of silver or raised from the floor on little ceramic pots, through hundreds of utilitarian digital switches, and eventually into your home via the cheapest connector that your telecoms company could provide. And yet it works perfectly; all the electrical noise of the world’s internet, and all the jitter that comes from being re-routed dynamically hundreds of times every second, is completely absent.

As I said in my earlier post, we need to understand the system at a higher level. Asynchronous USB and other on-demand packet-based systems are immune to cable quality once it is beyond some minimum standard, and electrical isolation removes the possibility of noise being injected into your audio system – even enabling you to listen to music off the WWW without all the electrical noise of the global internet spoiling your listening pleasure. Really, getting data from a file/CD/stream into your DAC and reading it out at a precise rate is a simple engineering problem, rendered trivial and cheap for the consumer by some very clever people who actually understand the problem, and have solved it.

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4 thoughts on “Digital cables: a lack of understanding

  1. I think that many people are stuck in the needle in groove to speaker analogue world.They do not appreciate the speed that digital data is transmitted and cannot conceive that there is time for packet contents to be checked, a request for retransmission issued and a retry sent.Tell them that packets can be received out of order,sorted into the correct sequence and then the data played back perfectly they refuse to believe it.

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    1. No, I don’t think they take kindly to dissenting voices on that site. You would be branded a “troll”, and hints would be dropped that you are only saying what you’re saying because you are bitter and twisted because you can’t afford expensive things yourself.

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