Hello,
I have been out of touch with headphones for a couple of years now, and was never really that "into" it to begin with.
A coworker at the time was though, so I listened to many headphones that he purchased, and from...
I've used the little dot II with the 580's, sounded good to my ears. I'm far from an expert . . . but I can tell you the amp is very much capable of driving the 580's. My 2 cents.
Sorry, I can't be of much help . . .
But I am very interested in any responses here, I have a 60gb ipod video and I just bought a universal dock . . . just to be disapointed by the fact that it doesn't have a "real" line-out...