mpd not outputting native DSD to Fiio DAC

[TheOldPresbyope]

I just looked up USB Audio Player Pro. Here's a snippet from the product description

SUPPORT FOR DSD

IF PCM AUDIO IS NOT ENOUGH

When you have a DAC capable of DSD (Direct Stream Digital), you can even play DSD (.dsf/.dff) files natively, providing a 1-bit digital stream (over PCM using the DoP protocol) like the Super Audio CD of past times! ...

Sure looks to me like it employs DoP also.

Regards,
Kent