Don't listen to this nonsense about your HD-650 being under-powered. Sure, they do benefit from better amps, but there is absolutely 100% no way an E9 can't drive an HD-650 well enough to sound good.
I can say for sure that the HD-650 is not muddy sounding out of the E9. It's even clearer sounding than even from the Asgard. Most people haven't compared them and won't agree, but that's OK.
Heck, even a $99 Total Airhead can drive an HD-650 decently. Seems most here think a headphone is underpowered just because they didn't like how it sounded.
These are the guys who also claim you need tube amps for a DT-880 in order to get sound...apparently most people here with a post count over 3,000 seem to think an E9 can only drive a KSC75.
I think it'd actually have a harder time driving that properly than an HD-650. No, I'm not kidding.
One learned I've learned here is that someone will almost always claim your amp/dac isn't good enough if you don't like the headphone that's attached to it.
BTW based on my experience, the HD-650 is quite good at making some lower quality tracks sound decent. I don't find them extremely revealing, but that's sometimes a good thing.
HD-650 certainly is no detail monster and I think most people would agree. Yes, this varies with cable swaps and better gear somewhat.
Edited by tdockweiler - 12/7/11 at 8:15pm