forgive me if this has already been asked in other forums. I've read many reviews/comments on the PA2v2 and obviously it is nowhere near as powerful as other amps, but given the price I don't see how anything really beats it. I currently hook it up to my TF10's (lost my IE8's unfortunately), source is Sansa Fuze, and it sounds pretty good as is (I use it everyday commuting to/from work in subway, so tons of background noise). I'm now interested in purchasing full sized headphones to see how they compare against IEM's. My question is what are the limitations of hte PA2v2? Will they be able to drive the Senn. HD650, HD600's ( i really like the Senn. sound) or the AKG k-701? Those seems to be great full sized headphoens that I can buy used at very reasonable prices. I know many of these "high-end" full sized headphones (without jumping into the ultra expensive HD800's, electronstatics etc) usually require a very good source and amp. I plan to use these full sized headphones for indoors only, mostly in my room listening to music / watch movies. It'll be laptop - Pa2v2 - full sized headphone. Any thoughts?