Think I'm gonna drop the ZxR soundcard. Looks like I can get this Magni 2 amp which is supposed to be ok to drive and a cheaper soundcard that uses Dolby headphone for virtual surround. The software for this creative is pretty bad.
Oh and btw, these HD598 fucking blow every gaming headphone set I have heard clear out of the water. Games, music, youtube, alladat. Hilarious.
That's because "gaming" headphones are almost always terrible. I wouldn't even bother with Dolby Headphone, that just degrades the sound quality and doesn't even have any better imaging than a pair of headphones with a decent soundstage in stereo mode.