Even burned-in, the Denon D7000 is sibilant on certain tracks. IMO, only the ATH W1000X can do what the D7000 does overall and surpass it. It's still a top headphone for what it does well. I suggest using an EQ to lower the highest frequency a little since you don't have something like a tube amp.
Don't consider the GS1000i. If the Denon is giving you sibilance on certain tracks, the GS1000i will most likely give you sibilance on the same tracks. The T1 should be better.
If I got a tube amp, would that reduce sibilance further?
A tube amp might reduce the sibilance, but it might also reduce bass control...IMO the D7000s are very difficult to pair with tube amps, though not impossible. I feel that perhaps another headphone might be to your liking, one with a gentler treble and very good bass impact. I found both T1 and LCD2 to have good bass impact and a less sibilant treble, I have never heard the W1000Xs, but from all reports they might fill your needs perfectly at a lesser cost. IMO the D7000s are fundamentally a very bright can and no amps will change this fact.
Edited by SP Wild - 12/26/10 at 12:38am