So it will do 2xDSD over USB. Is this native or DOP?
DSD files come in either a .dff or .dsf extension.
DSD (DFF, DSF) files :
DSD Storage Facility (DSF) files are far better suited to music library management because they allow the inclusion of metadata. This embedded metadata includes the names of the audio contained, information about the release the audio is part of, and other data such as album artwork. Hence, a DSF file could be transferred to different music players and retain the same metadata.
DSD Interchange File Format (DFF) files don't allow any tags to be stored, making music library organising much more difficult. Storing information about the audio means using separate databases, which is a pain when moving the music from one system to another. Each time you import a given DFF file into a new music player, its metadata may not be recognised, making your library a pain to navigate, browse, search and generally use.
DoP DSD is "native DSD".