Andy Peters wrote:

You're confusing "USB 2.0" with "high speed USB." While USB 1.1 had
two speeds (low, at 1.2 Mbps, and full, at 12 Mbps), USB 2.0 adds a
third speed (high, at 480 Mbps), but a USB 2.0 _device_ does not have
to support high-speed transfers. However, note that a USB 2.0 _host_
must support high speed.

I'm not confusing anything, I'm just not familiar with the terminology.
I only know USB versions 1 and 2, and 2 is capable of much faster
transfer rates. Since it's backward compatible, might as well use it. I
know that disk drives connected to a USB2 port have a much higher
throughput than when connected to a USB1 port. That's good enough for
me (as a user). Designers may, and probably do, see it differently, as
do the bean counters.

What Edirol is saying is that if you connect the UA-101 to a USB 2.0
host (which, as noted above, must support high-speed transfers), then
the device will do multiple channels at 96 kHz, as the device will
enumerate as a high-speed device. However, if you plug it into an
older USB 1.1 host, which doesn't support high-speed transfers, then
the device enumerates using a full-speed configuration which only
supports 48 kHz stereo.

This is similar to my laptop situation. It has only USB1.1 ports. When
I plug a disk drive in a USB2 case into the computer, it runs slow
enough so that I can only record about 6 tracks at 44.1 kHz without it
getting behind. If I plug the same drive into another computer with a
USB2 port, it works just like an internal disk drive.

Bottom line - sufficient speed for 96 kHz duplex stereo is available
through USB. You just need to implement it properly, which is what
Graham is trying to find out how to do.