Here again. on the amps you've heard them on maybe not. However, on the amps I've heard them on many of times side by side and for more than a year together, the one and only thing the HD800 has over the HE-6 is soundstage and TBH the soundstage on the HD800 can sound fake with some music, all music do not require that size of soundstage. Upper mids, lower mids, mid bass, sub bass all are wins for the HE-6.
Also the HE-6 / First Watt F1J / (Master 7, PWD2) blew away the HD800 / GS-X mk2 / (Master 7, PWD2) combo Oh yeah - isn't the GS-X mk2 your go to TOTL amp for the HD800s?Also I think Soulde sold his HD800 for the LCD-3s because the LCD-3 made his HD800s sound thin..
A few things...first, the HD800s make the HE-6s sound thin and NO amp can fix that. Oh and Solude was never impressed with the First Watt amp he owned either. Please re-read this as it's all I have to really say on the subject you've just mentioned about unicorn amps:
"But I think we've embarked down the path of another myth. The magical unicorn amp/synergy myth (or at the very least: a dramatic exaggeration) where only a very select and rare amp can totally change the character of a headphone to make it sound like a brand new headphone. If there was, then I'd reckon that TOTL amp wasn't truly TOTL as it would have to be so coloured to do this. The HE-6s are purely a resistive load (being orthos) so put enough clean current and supply enough voltage and don't drop out of Class A; that is the definition of " good power" as you previously mentioned. Is there another mystical version of power I don't comprehend? Sorry, but I'm not going down that path. I'm very glad to see that the folks on the HE-6 thread no longer require 300W monoblocks to get that unicorn level of power as Daniel pointed out, but there is another unicorn now being touted and I'm sorry, but I just don't get it.
You're use of hyperbole isn't helping either as my impressions don't jive with yours (as do objective measurements that don't wanna jive with them either).