>Their statement that "Most USB audio/video devices use the bulk transport because real-time delivery of the data is not necessary" might be true, but certainly not for the sample of products bought by head-fi users.
that's what I told the guy as well. IDK, maybe he meant USB headsets or something
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I've just sent him a follow up email on the two questions now. Although he probably realized if he continues replying, he'll probably be spending a bit of time and there will be more questions
I think EMU series USB cards might use bulk mode as well, but not too sure (might be async as well). Maybe 2-3 more in the pro audio or audio-unicorn world
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a large majority of head-fi DACs or transports with USB section definitely use isochronous adaptive mode. Maybe 5% use asynchronous if not less.
And as I said in the post above I also very strongly suspect the proliferation of adaptive mode DACs seems to be simply because it requires the least amount of effort (slap it in, no additional firmware or drivers, and simply output to I2S or something...)
It's pretty doubtful that USB.org would have any sort of stats, since it's more to do with the number of chips supporting adaptive and async modes and the willingness of manufacturers to use bulk mode... or rather unwillingness. (and who can blame them if you need a driver for win, lin/mac (and potentially firmware on the receiver side in case you don't get it right on the first go)....Although a reference implementation could've been provided by USB.org or whoever else to assist, but you know... every receiver would have its own quirks/every major OS upgrade might also have audio related OS changes...Development and maintenance of the firmware and driver code is not an easy or cheap task, and why bother if people buy adaptive anyway and then just say 'oh no adaptive is just as good, it's all down to implementation' (that's marketing BS, for adaptive it seems to be about the USB receiver chip itself and its stability, jitter, etc...since you're just vanilla connecting that to the I2S on the DAC, or ASRC, or reclocking of some other sort, but hey, who are we to kill unicorns))