[sky176]

As I know, Asynchronous USB is a sort of Isochronous transfer (Isochronous, Control, Bulk & Interrupt transfer)

IF any data goes wrong in the transfer, the computer is not going to resend the data again like Bulk transfer. Since there's no data checking/resending, therefore, isochronous transfer is no way to (only very close to) get "bit perfect" to my limited knowledge.

In order to get very close to "bit perfect" a good USB cable should be there for asynchronus USB connection. Am I right? Has anyone TRIED to compare cheap and good cables in asyn USB? Or Steve may have a better understanding of it?

[wilsynet]

Cable matters much much less in asynchronous USB than in adaptive USB.

[audioengr]

As I know, Asynchronous USB is a sort of Isochronous transfer (Isochronous, Control, Bulk & Interrupt transfer)

IF any data goes wrong in the transfer, the computer is not going to resend the data again like Bulk transfer. Since there's no data checking/resending, therefore, isochronous transfer is no way to (only very close to) get "bit perfect" to my limited knowledge.

In order to get very close to "bit perfect" a good USB cable should be there for asynchronus USB connection. Am I right? Has anyone TRIED to compare cheap and good cables in asyn USB? Or Steve may have a better understanding of it?

I have compared them on my 192 async USB interface and I cannot tell any difference, at least in the time period that it takes to restart Amarra, which is necessary if you unplug the cable.  Maybe faster switching of cables would detect something, I dont know.  I just use a cheap 5m USB cable or a Belkin Gold.

There are other async interfaces where this seems to be more significant however.  Explanations may be RF effects, radiated emissions, power modulation, and even somehow the jitter bleeding through, which should not be possible.  Just guessing.

Steve N.