I believe so. I tried the T1 via the HPO of my Cowon X7 and it sounds great!
The Cowon's have good quality outputs, but the T1 is even better. Because the Cowon starts off good, the T1 is able to amplify a good quality source, but also seems to lend it's ability to control and maximise the earphone's sound. I noticed improved dynamics, bass and staging from the T1+X7 combo.