Not for US, I believe, don't know if Sennheiser care, some manufacturers like Canon do.
Edited by Andrew_WOT - 1/26/13 at 2:34pm
I'm kind of tired of my HD 800s, technically they are good performers but they lack body and warmth in the bass and the treble is a bit too bright (like so many feel). I never use them anymore and I much prefer my Momentum for long listening sessions. The tonal balance is more natural there.
Maybe one should try a tube amp? Any serious recommendations at a reasonable price? Nothing overly fancy, no big, balanced powerhouses - just a great sounding tube amp that will make them shine. If the combination is successful, one could always upgrade to something more "high end" later on.

I'm kind of tired of my HD 800s, technically they are good performers but they lack body and warmth in the bass and the treble is a bit too bright (like so many feel). I never use them anymore and I much prefer my Momentum for long listening sessions. The tonal balance is more natural there.
Maybe one should try a tube amp? Any serious recommendations at a reasonable price? Nothing overly fancy, no big, balanced powerhouses - just a great sounding tube amp that will make them shine. If the combination is successful, one could always upgrade to something more "high end" later on.
I use the Decware CSp2 with the Amperex Bugle Boys and Sylvania 5U4G and find no brightness just great soundstage and pipoint focus with warm kids but not syrupy and great bass definition. I won't change that combo
I have a Musical Fidelity M1HPA right now and I'm looking for something at a similar price range.
I don't need balanced as my source is single ended and I use the stock cable.
Really not sure what your price range is but this amp is said to be a really good amp at a pretty much OK price.
http://www.eddiecurrent.com/Zanadeux.html

^^^^^ Agreed. ;) Probably out of his budget though. Maybe a Woo 6?
-Daniel
Woo Audio 2 
awesome pairing with the HD 800
Been listining to my 800's for the last few days.Definatly a keeper.
no problems with the treble what so ever.i dont find it harsh at all. not like the k701.bass is great as well,perfect quantity and quality. not as overpowered,bloated to some degree like the lcd2.but im not a fan of the lcd2 since i think there are major shortcomings in its sound especially in treble,resolution and soundstage.i had hd650 for a year and thought it was better than the audeze due to its more coherent sound.
my only criticism thus far with the 800's is soundstage depth. its wider than deeper which can be a bit distracting on some materials. but then again,i think that will be resolved once i build the b22 in few months.
overall,very happy with my purchase.
the WA6 is enough for the HD 800, some ppl love it with the hd 800, though some people find it lacking still. i haven't personally heard it though.
the WA2 is much better, it doesn't work with low impedance for me (clipping past half volume, low volume level unless using low gain tubes) or for some other members here, but most members here seem to have no problem with their WA2, most people find it does great with low impedance and even harder to drive stuff like K701, HE-500, and LCD-2
I have very limited chances to try out different sources in my chain and even more limited budget. My DAC is a DIY, PCM2707 and a very high performing tentlabs clock. But I really hear no difference between it with the M1, and driving the cans directly out of my iPad. Volume is higher but the sound is identical. Very disappointing but that may just be the "truth" behind hi-fi. That's for another thread though ;)