Zmanastronomy, thanks for pointing out the Mutec devices, which certainly look interesting if not particularly inexpensive (the 1.2 appears to sell generally in the area of $450).
However, after looking at the manual for the 1.2 (
http://www.mutec-net.com/downloads/manuals/MUTEC_MC-12_Manual_E_screen.pdf) I’m not at all sure that it would do what the OP requires. If the device is provided with a S/PDIF or AES/EBU input it can convert those signals to a USB output, but while it is not made entirely clear in the manual or the website description I believe a computer or equivalent would be required to receive the signal from that USB output. For example, note this statement on page 16:
The digital audio signal received at the selected input will be converted into an USB audio stream and send through the USB port into your computer, laptop or music server.
A typical audio DAC will certainly not be able to interrogate a USB output in the same manner a computer can.
And note that the USB connector on the device is USB type B, which is ordinarily used on peripherals that interface to a computer, not on the USB ports of computers or computer-like devices that communicate with those peripherals.
Regards,
-- Al