Cowon iAudio X5

It's a great music player. I play some full sized headphones with it, a pair of YH-100, with plenty of bass and volume. That said, audiophiles will need no extra amp with your gear. Luckily I got mine used and with a few updates it's as good as new; plus it's discontinued and 5 years old at this point. There's no software that I could find to sync with it but it will upload with your MP3's straight in like an external hard drive. It was surely ahead of its time