Got my HE-4ooS and could not be happier.
Glad i sold my HE-4oo for this.
This headphone is a little wonder
The HE-4ooS is darker than HE-4oo
-Wow, I was quite surprised, it took me a little time to adjust, i didn't expect this at all (i thought i was going to return it at first, it just threw me off).
-I already sold my HE-4oo and was back on the K712 until the 4ooS arrived, and it felt a little weird going on the HE-4ooS.
-The HE-4ooS has better Soundstage than HE-4oo.
The HE-4ooS sound signature is overall less fatiguing than the HE-4oo
-The HE-400 treble was tough on you after several hours.
-The HE-4ooS is more neutral than the HE-4oo.
-The HE-4ooS has less bass than the HE-4oo. (personally, i think it still pack a good bass)
The HE-4ooS is more comfortable than the HE-4oo
-They are world's apart, the HE-4oo would, well, i wont say
hurt the top of your head but, you felt like you
needed to take them off after a while.
-I would rate the HE-4ooS more comfortable than the K712 as well, simply due to the fact that your hear can go deeper into the headphone without touching the inside.
(The K712 is comfortable but my hears always slightly touched the inside and that was a little annoying.)
The HE-4ooS headband has quite some clamp out of the box and need to be kept stretched a little.
Aesthetically the He4ooS also wins (what a beautiful piece of gear).
Also just like the HE4oo, the headphone rotate left and right, but this time it's much smoother (the he-4oo was too rigid and painful to rotate) and that makes a huge difference.
This seems irrelevant, but it changes everything when you take off and on your headphone (it's something you need to have in hand to understand).
HE-4ooS cable is really short
Note: these are impressions based on a HE-4ooS with a Matrix M-stage with class A biasing mod with Burr Brown OPA627AP and a Prodigy HD2 Burson.
Someone also mentioned an extra screw hole in his headphone, mine has the same but all screws are in:
(No buzzing so far)
Pics: