Audio advisor has tha nuforce usb to coax/optical converter for $49 now. I have had the model from eBay/Breeze Audio and a Hiface two and the nuforce is my personnel favorite. Notwithstanding any non-scientific BS including marketing claims the published measurements on these show they produce...

  I meant to say I haven't found a way to get the apple music app to play from a usb drive.

  Good thing you asked! I went back and tried every combination I could find. Only the following combinations have worked with the externally powered Hiface two on my system:   jailbroken iPad with "card reader + hub"   jailbroken iPad with Apple CCK + good quality (Targus) USB hub  ...

I got the HiFace Two usb/spdif converter to work with my iPad 1 today. The problem isn't the iPad or the HiFace, it's the apple CCK. I replaced it with "Card Reader + Hub" I bought on ebay.  ...