On the mpd forum there was a post with some playback problems. The guy posted a link to the soundchip used.
The specs are just horrible.
It’s a 24bit card (high definition audio) , but it you check the DAC’s output it only gets an ENOB (effective number of bits) of 14 bits (headphone only 12 bit), that is 10 bits less then the device is capable off. Now there are hardly any DAC’s that can do 24bit, but this is terrible it does not even do 16bit.
This cards THD is 86dB. (76 for headphones)
16bit requires 98dB
24bit requires 146dB.