also, on the subject of james' comment regarding "flac, alac, etc" as alternatives. you cannot possibly serious about this. You put only 8 gigs internal memory into this product, did not include any memory card, waited 3 months before we figured out how to even get 64 gig cards to work with your product in the first place, dont have any exfat support for the cards, and you're seriously telling people with entirel libraries of mp3 to re-acquire their library in flac/alac/aac?
If that is the mindset, then until the bugs that should never have existed in the first place are fixed, you should reacquire our players and have us reacquire our money.
I'm sorry to be harsh, but you've released a product and people have certain expectations of the product. You need to meet those expectations (working UI with proper sorting, working file formats, working SD card) before you try to exceed those expectations (usb dac functionality). You are fiio. You released a 200 dollar product. we expect E7-level sound from this, not AK120 level sound. If you priced it at 1000 bucks, we would have expected AK120 level sound, and we would have been far more furious.
You have an open policy in which we tell you what problems we experience with the player, but dont tell us that "its too difficult" to do something. Its not. Either your developers are too busy with some other random new feature that they feel is important, or you simply dont want to listen to users anymore. The fact of the matter is, you are missing some very basic functionality and until that is fixed, this exceptional product is not that exceptional.
You've already gone above and beyond in the hardware department because of connectivity options (line out, coax out, crazy durability, excellent battery life, pre-installed screen protector).
You now need to make the software simply catch up. Stop trying to add new features to wow us. we're wow'ed already, just make it work the way it is supposed to. First fix bugs. THEN add features. dont add features and then tell us the bugs are too difficult to fix.