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High Speed USB DAC?

A recent article in Stereophile ( July 2011, page 45 ) indicates better sound may be achieved when a USB DAC is on a High Speed USB bus.

I have a PS Audio Digital Link iii. My Mac Mini, using as Music Server, will only recognize the USB Audio Codec ( PS AUDIO DLiii ) on the Non High Speed USB Bus. I've contacted PS Audio and they don't seem to have a clue about this. Anyone know if this device is capable as a High Speed USB device? Am I wasting my time and won't see any realistic sound improvement?

Thanks in advance
giantsfreak
audioengr
3,282 posts
 
If the change is from USB 1.1 to USB 2.0, then it probably means that the USB interface changed from adaptive to asynchronous. This means that the computer instead of "pushing" data to the device, the device is now "pulling" data from the computer. This establishes a master clock in the device.

Steve N.
Empirical Audio
thesoundhouse
250 posts
 
In the case of the Ayre QB 9 it was asynchronous already with the USB 1.1 input with the USB 2.0 it now allows more bandwidh i.e. 192k to flow. Another good example is the Music Streamers second generation DACS which now have input receivers capable of 2.0 but only have 1.1 USB software. They are asynchronous and are considered USB 1.1 and can play 96K files and is asychronous. The next generation Music Streamer will probably address USB 2.0 and allow for decoding and playing 192K files.
giantsfreak OP
4 posts
 
Thanks to all for your responses. PS Audio confirmed that the Digital Link iii will not show up as a High Speed Device. They also confirmed that high definition (24 bit 96/192) capable USB DACs will utilize the High speed bus while the DLiii is only 16/48 USB.
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