19 out of 20 people on headfi say that they need an amp to properly drive whatever they are listening through. Personally, I think, my SE535 does great from an ipod classic. I sold my C5 and pocketed the $150. I just couldn't hear an improvement, though there was a difference.
I think most of us prefer not to use an amp. I have had a few to check out but nothing wacky and used a Fiio LOD. The no required amp consideration is part of my IEM selection process and will again be with my next DAP. My IEMs are a benign, nonreactive 28 ohms. The new Shure is 9 ohms with a normal network besides the acoustic woofer low pass. Seems an odd choice for a ground up design and seemingly aimed at <1 ohm amplification. I also thought the 530 was fine sans amp.
Edited by goodvibes - 5/11/13 at 6:51pm