Very simple amp that just happens to mate well with them is the jdslabs O2. Thats the 250 ohm dt250 by the way. The 80 ohm model is not in the same league as those open cans. With almost every genre thrown at it, the dt250-250 is just better than the hd600 or 650 out of basic amps like the o2. The he6 I tried was driven out of an audiolab amp's speaker taps by the way.
I wouldn't believe it myself if I read my comment without having heard the cans... But in the end, every single headphone I've ever owned always went for sale in a short time due to having problems that annoyed me in one way or the other. The dt250-250 is the first pair that just works with everything thrown at it and Ive had them longer now than any other headphone I have ever owned while being on headfi.