S.M.S.L SD-9 MQA Full Decoding Bluetooth 4.0 HiFi Network Music Player SD9 Support DSD, WAV APE,FLAC AIFF, MP3 Desktop Player

I bought the SD-9 to replace 2 other devices, a Shanling M2s and a Quloos QA361, as a source component in my home audio set-up; it has lots of digital outputs, including USB and S/PDIF, that the Shanling and Quloos can only provide separately.The fact that the dual USB-A ports stick out of the back of the device slightly, i.e., they're not recessed like they would be on most devices, is the only thing that really detracts from the aesthetics of an otherwise nicely put together unit.The user interface is where the SD-9 fails to meet expectations, even at this price point. I use either the front-mounted control knob, or the supplied remote, to navigate the menus. The control knob doesn't protrude as far as that on SMSL's SH-9 headphone amp and as such, is a little awkward to use. Advancing through the menu structure is a case of rotating the knob, either clockwise or counter-clockwise, then pressing it (clicking) to make a selection, which works OK; unfortunately, there's no facility to step backwards, so if you want to move back up the menu structure, you have to double-click, which takes you back to the home menu and you have to start over. The remote however, does allow you to step forward and backward through the menus.During playback, the 1.9" screen displays pretty much all the info' you need about the track, along with various system status icons, but if you're sat more than about 2m away, it's unreadable anyway. It's during navigation that the screen size becomes particularly problematic; it only displays 3 menu items at a time, so if your music library comprises thousands of tracks, for example, that's a lot of scrolling to find something specific.There are other things as well, that irk me, like having to specify the music source every time I use it. It would be helpful if the unit could scan all connected storage devices and only display what it finds: why do I need to select the source from a list of 5 or 6, when I've only got one storage device attached?Also, why are the "Now Playing" and "My Music" menus identical? Get rid of one of them.My Shanling M2s has a tiny control wheel that, over time, has become more sensitive, to a point where it's now unusable, so I've resorted to using the Hiby Music app to control it: the SD-9 is pretty much the same; it offers nothing that I need, that my other 2 devices don't already provide. The perceived convenience of having the functionality of both, combined in a single device, doesn't exist, hence my decision to return it.