Final verdict from me (intro):   Originally I had listened to the K712s on a Yulong U100 and they were the most expensive headphones I'd ever used. I was dissatisfied but I didn't feel it was fair. I don't want to be the guy running in frantically, waving his arms, talking complete nonsense.    I have spent plenty of time with these headphones now. I have A/B'd them with a the Avid Omni HD, Yulong U100, Yulong DA8 (through the headphone out and via the Denon PMA-750) as well as straight out of my Galaxy S Note II. I've pitted them against the...