Ok Having spent most of the morning (o gosh it is already afternoon!) listening, going back and forth here are some early thoughts:
The difference isn't subtle, but it isn't night and day. It's a lot like the differences between many TOTL headphones, the differences are slightly exaggerated when you try to express it writing.
To repeat what pretty much everyone says: HD800 Classic is brighter, HD800 S is warmer. Both are detail monsters with big sound stage. But wait! There's more...
So far I have only listened to rock music, since that is where I found the classic sometimes problematic. I will listen to acoustic Jazz, classical (chamber and symphonic) and other genres later. Mostly I listened on my Lehman BCL because I can go back and forth easily since it has two single-ended head-outs. I have also listened a little bit to my Icon Audio HP8 mkII amp with NOS sylvania 6SN7 (70s) and a modern JJ gold pin ECC83, my current fave tubes so far. I need more time, but I have a feeling that the classic is more amp sensitive than his younger brother. But that is total conjecture at this point. But if that is true then the total cost of ownership for the youngster MIGHT be less than his more picky older bro. But I really need much more than 4 hours and two amps to be sure. I can say that so far on rock music the Icon seems to be less better than the Lehmann BCL with version nouveau vs. classic (where the ICON's charms are more immediately obvious).
I can see some people who have been using the HD800 for years now, preferring HD800 classic, but for most others, I would guess HD800 S would be preferable.
Listening to the hi-res, Stephen Wilson remix of Yes's Fragile, the classic sounds a little sibilant on Roundabout: "I'll SSSSpend the day your way". The youngster reveals no such emphasis. The album is musically amazing and but the recording quality, even after it's been Steven Wilsonified, is so-so. The youngster just sounds so much more right. The classic has a tendency to sound grainy on this recording. For example the South Side of the Sky sounds like the VU meters are way into the red when the sound it at a crescendo, ("seems like all eternity), well at least if you are listening to classic. But the young guy makes this sound, well, smoother.
The heightened treble of the original does give in some cases the sense of a little more air and details.
As and example of this, I was listening to a hi-res version of David Gilmour's newest, Rattle that Lock. The song Dancing Right In Front of Me has a beautiful solo towards then end. Under the guitar is classic sounding Floydish background vocals. It sounds further down in the mix on the youngster and noticeably more up front on the classic. I would recommend that anyone who has the HD800 try to demo before upgrading. Or maybe not because I think on balance the new HD800 S is probably the more sonicly accurate headphone.
The youngster seems to be better suited to brightly recorded and poorly recorded material.
More to come....
