I’ve heard the hd800 a bunch of times with many very fine balanced amplifiers, and it still remains a huge disappointment to me. Sure I’ve heard it sound like something approaching very good on a couple amps, but not good enough to perform in the top tier IMO, and it shouldn’t be that hard to find a match for a headphone. In a typical case, it’s almost impasible for me to enjoy music through them. It always reminded me of a poor Sony Qualia 010 clone, with perhaps less severe weaknesses, but also with greatly weakened strengths.
I love to complain about the hd800 btw