Hey Guys,   I have been trying to follow the thread and not sure i completely understand what is the best solution.  I have a Fiio E17, Iphone 5C and multiple headphones (Sennheiser 598 (50 ohms), Audio Technica ATH-ANC9 (100ohms) and Denon AHD- D7000 (25 ohms).   The E17 worked fine on my...