isosynchronous ?

Discussion in 'Hi-Fi Stereo Systems & Separates' started by davidguest, Feb 12, 2014.

  1. davidguest

    davidguest
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    (realtes to another thread of mine but may work better as a fresh new question.)
    Cambridge audio tech support tell me:
    "
    The 351A is a driverless USB 1 isosynchronous type ..."

    but Google/ Wikipedia seem unfamiliar with that term.

    I find only main references to isochronous

    so is that the same thing ?. and ( for dummies please) is it better to have asynchronous for PC to DAC

    PS to add to my confusion, I find an artcile that says:
    Isochronous transfer can be done with three possible types of synchronization ... synchronous... adaptive.. asynchronous

    USB audio
     
  2. Mark.Yudkin

    Mark.Yudkin
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    I would assume it's a typographical error - the English word (the word you'll find in a dictionary) is isochronous. Here's a different explanation of the terms:
    More importantly, USB audio is always isochronous. You can't have asynchronous PC -> DAC transmission for audio (using the word as per its meaning), this is equivalent to saying "totally non-functional by design".

    However, a lot of DAC advertisement copy writers abuse long words (like the article in your link) and use "asynchronous" to mean something totally different (just like Humpty Dumpty with Alice) - specifically to mean a transfer in which the DAC controls the clock. This is of course not asynchronous in the dictionary definition of the word, but since its a long word many don't understand, it sounds good, just like all that technobabble on Star Trek. Of course, it does confuse the hell out of many others, so when you see "asynchronous" in the context of USB audio, just read it as "wombat".
     

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