OK guys. I have decided to return my FIIO E17 which is driving my HD650s. Honestly, compared to the Cirrus Logic 4206B in my 2012 Mac Mini, I honestly can't tell any difference from the Sennheiser HD650, even with FLAC music files. I am not an audiophile, but I do appreciate good music.
To make matters worse, the firmware in the E17s is VERY VERY buggy. The hardware feels very solid, but the software interface is atrocious. The hardware feels good, but FIIO really dropped the ball with the firmware.
I constantly experience pops, sound hiccups, and once a day I have to disconnect the USB cable and reconnect. I even experienced my FIRST BSOD with Windows 8 (WTF) when I disconnected the USB cable. Overall, I am really disappointed, even for the $90 price tag from Adorama.
I know I shouldn't complain for the $90 price tag, but what other options do I have for less than <$200 for my HD650s?