You could actually get away with the above if you get the (IMHO superior) Titanium HD instead of the STX.
Why you think the Titanium HD is better than Asus Xonar Essence ST ?
The ST has best signal/noise 124db and best analogical quality 192hz than Titanium HD who has only 92hz.
And i don't like Grado sr60 for music lack bass and low and soundstage for gaming
Tiihokatti : i see you have the Dt770 you think ad900x is better than DT990 ?
Audio Technica is avialable on Amazon.fr et some sites but the AD700 in amazon is only available used