love my DT770 - I picked up a Xonar DG to pair with it. And the difference is quite noticable. I'm not longer looking to have my audio output jacked up to near 100% and the sound is overall richer/fuller. And that was just with an entry level sound card. I've the sounds I get out of them... i'm not a seasoned head-fi'er but I wouldn't bother looking to upgrade your can's unless you've gone out and listened to a different pair that you enjoyed better then your current setup. At least that's where I'm at now that I have my DT770's. I may look to get a different set of open instead of closed, but I'll most likely go somewhere to listen to a could of different brands prior to making the buy.