I just received the Aune X1 DAC this morning, managed to listen to it for 15 minutes before going to work. Plugged it quickly in over USB and used a stabilized adapter I had lying at home (14 V, 800 mA) since the default wallwart would hog up to much space and had the wrong connection.
Anyway, the first thing I noticed compared to my Zero DAC (old version without USB) and Behringer SRC2496 was how widened the soundstage was. I have always liked the soundstage on my Beyerdynamic DT 990 pro (250 Ohm) but the Aune X1 really made them sound bigger and more spacious. It also packed a nice punch, playing more powerful than the Zero. And this was during the first 15 minutes :) During my waiting time for the Aune to arrive from China, I listened to some music comparing FLAC and 320 kbps for the same songs and was a bit disappointed in my self for having difficulties hearing any difference, thinking to my self "why do I waste money on things if I can't here the difference...". So my initial expectations was not to hear any difference at all compared to the Zero, so I was a bit shocked, putting a big smile on my face because of how good it sounded. I will say though that it sounded a bit brittle and harsh, but only veeery slightly, and this could be because of the more detailed sound I was not used to, or the lack of burn in.
The widened soundstage gives me hope to actually like my Grado SR225, since I have always hated the "in my head" presentation, placing them in the box they came in most of the time.
I have also a couple of Beyerdynamic DT 150 on their way, and after reading about their sound signature I am looking forward to listen to them with the Aune X1 DAC. Music I listened to during my brief testing was some Meshuggah, Arcangelo Corelli and Frank Sinatra, so quite a mix of music :)