[TrollDragon]

I've had a few embedded developer boards from Renesas (RX62n), STM (STM32F2 & F4 Cortex-M4) & TI (Stellaris Cortex-M3) plugged into this PC over the while, a few of those have had an I²S bus available so it is possible a driver might have been installed with the IDE packages.

 
I took the unit over to a friends house and it showed up as "Speakers" as well on his OSX 10.6.8 which already has USB Audio 2 by default I understand.

 

[jackwess]

Generic usb drivers (native windows drivers) doesn't support anything over than 16 bit, 48 khz. That's why it's important to use the manufacturer provided drivers for higher resolutions. 

 

[TrollDragon]

USB Audio 1 spec is 24/96 is it not? Windows 7 supports that out if the box with my E17 UA1 device.

 

[StudioSound]

  I've had a few embedded developer boards from Renesas (RX62n), STM (STM32F2 & F4 Cortex-M4) & TI (Stellaris Cortex-M3) plugged into this PC over the while, a few of those have had an I²S bus available so it is possible a driver might have been installed with the IDE packages.

 
I took the unit over to a friends house and it showed up as "Speakers" as well on his OSX 10.6.8 which already has USB Audio 2 by default I understand.

Maybe it's reporting as a generic soundcard rather than a USB Audio Class 2 device? I really couldn't say.
Windows definitely does not support UAC2 devices without installing a driver first though.
 

USB Audio 1 spec is 24/96 is it not? Windows 7 supports that out if the box with my E17 UA1 device.

Yes, Windows will do 24/96 with UAC1 devices. (or devices running in UAC1 mode)

 

[uncola]

windows 8.1 seemed to have a built in usb audio class 2 driver for my dac that used a cmedia cm6631a usb receiver chip..