Got my replacement DX50 from iBasso and have left it running for 40 hours.
Doesn't sound as good as my last one, and sounds worse than my cheapo Fiio E17.
Sounds slightly closed in, less dynamic, less detailed.
I have reset, reloaded, rebooted, checked ground connection, using hi-gain and so on. Very unhappy since I can't return this one, since there's ostensibly nothing wrong with it.
Just hang on, mine took a day or too to take out this screechy high pitch sound, then went smooth like silk. You gotta burn it and also go through full battery charges. If you want just run it with your earphones connected but don't listen, let it run for hours. When I got mine the first week I was ready to return it, patience pays off.
Edit: just read you did 40 hours with it. I am shocked tbh when I reconsidered to keep the DX50, I felt happy I did not ditch it immediately, to me it got better with time. I think you should use it for a full week from that point with different iems headphones and judge if it's any better, if you find it's not for you then sell it, you'll find happy members willing to purchase it.
Edited by musicheaven - 11/1/13 at 1:01am