The X3 is crazy powerful. It powered every headphone and universal iem i've tried at the recent Mook festival in Singapore.
The Final Audios (iems) even Pandora 6, the fitears, the JH audios 13/16, the Fostex Tr50p, TH600, TH900, the beyerdynamic T1, etc.
The X3 took them all on and all sounded mighty fine and then some. Truly a pleasant though little surprise (E17 amp inside after all).
Had the AK120 as well at the same time and well ... they do well with the iems. Will just leave it at that.
The DX50 is also good, the dac tuning to me seems very well done, though the amp portion may be the weak link in the chain. As a layman user, the sound coming out of the DX50 headphone and line out, are very different and pairing with a good amp (tubeamp ta1 or alo rxmk3b+), shows the dx50 could be a better player.
Edited by kenz - 10/27/13 at 3:36am