Is there a usb dac out there that does not need a pc

ie the dac itself contains a microcontroller
so that it can be a master. The input would be
a bunch of uncompressed wav files from say,
a usb thumb drive. This external thumb drive
would be slaved to the usb dac - a transportless
digital source with the possibility of minimal
transport induced jitter. A really low jitter clock
can then be used.

Does such a kit or project exist?

Or can the std usb receiver chips from TI etc be
used with some simple glue logic and clock to
accomplish this?

TIA
tinears