as it turns out, it was an apple setting. under audio midi, the Teac was set to 16 bit integer -rather than 24 or 32 - which is apparently needed for DoP. thanks for the help though, bflat ..

Just to update (in hopes of a reply!):   The online documentation for  the TEAC HR player says it uses DoP for Mac's ... and since I was able to successfully play a DSD file via the HR player, the UD-503 must accept DoP via the USB port. As a side note, the display on the UD-503 only indicated...

Hi-     I tried this on another forum without luck. Hoping someone here might be able to help!     I had been happily playing DSD (.dsf) from a Mac/Pure Music to an iFi Micro, but recently changed to a TEAC UD-503 DAC and can't get DSD to work. After trying to troubleshoot, I've come up with...