For full list: http://www.asustor.com/service/dac?id=dac
Also, you can enjoy DSD format via Hi-Res Player(rompr-mpd)
About Hi-Res Player
Description
The Hi-Res Player is a music player which you can play the Hi-Res Audio (higher than CD quality - lossless music format - FLAC, WAV, DSD etc)
It is the App which integrated the MPD (Music Player Daemon )with Rompr UI.
Support formats: Ogg Vorbis, FLAC, Opus, WavPack, MP2, MP3, MP4/AAC, DSD (.dff)
More about Hi-Res Player: http://www.asustor.com/apps/app_detail?id=375