|Yes, they are picky. The better the amp you throw at them, the better they will sound.
are you talking about the 600 Ohm version of the 770 Pros? Have you tried the 250 Ohm version yet? I recall that you meant to get them as well, didn't you? Please post a review of both of them as soon as you can! I am very curious.
the 250 Ohm version of the 770s has worked great for me no matter what I plugged them into so far: TV sets, VCRs, DVD players, CD-ROM drives. Battery-powered PCDPs might be a little to weak for this load, though.
Okay, I admit, they are best when driven by my Earmax Pro. Dusty is very much correct: They benefit from a good amp. And they benefit a lot from a great amp. But they certainly are not as difficult to drive as a Senn HD600 or an AKG K501.