I just spent the past 2 hours comparing the HE-300s with my Grado HP1000s and Senn HD600s/Cardas cable combo. I only have about 30 total hours of break-in on these cans now so I'm still expecting them to change some more but here are some early impressions. Source is the standard off the shelf OPPO BD83, unmodified, Tara Labs Master Gen 2 interconnects to a Modified Ming Da MC34-B. Critical listening for this session was with Patricia Barber's Nightclub on SACD. All of track 1 in a loop for round 1 of testing followed by the first 1 minute of track 3 in a loop for round 2.
On all three headphones, Patricia's voice had what I guess you call a sibilance that was a little edgy. Most notable on the Grados but still the on the Senns and the HE-300s. I haven't tried any other cables, sources or amps at this point with this SACD. The HE-300s were mostly compared to the Grados. The senns just don't have enought detail with this amp to be in the same league but they do have a fuller but less detailed bass and a very soft and veiled high end. I will probably drop them from the comparison with this hardware configuration. If I change amps, I will add them back in.
The Grados were more transparent but thinner with maybe a touch more detail. All the instruments were much more detailed and fuller on the HE-300s. Soundstage was about the same for both but I would give the musicality edge and frequency response to the HE-300s. Even listening to some really old remastered Traffic and The Band last night, I found myself getting into the music more with the HE-300s. The HE-300s, however, are not for poorly recorded music. Last night I put on a DVD-Audio recording Donald Fagen's Nightfly and found it very edgy on the Grados and HE-300s but less so with the Senns. Bad hi-res recording? I seem to remember the original cd was also very bright. I think that was the very first cd I bought when I got my Sony CDP-101 player back "in the day". The HE-300s aren't very forgiving. Next on the agenda is Classical music on SACD.
I am having an issue with my Nuforce Icon HDP through the computer so I will post notes later on that combination. Sorry Texasbuck, I know that pairing is of interest to you. I'm planning to disconnect it from the computer and move it into the bedroom computer and hook it up via coax digital to the Oppo on Monday. I won't be able to test the Icon's high res until I get the computer pairing issue resolved. But for now, I will continue to try different high res disks and redbook cds.
Anyway, since I am off work this next week, I plan on doing a lot more testing and adding more hours to the break-in time. Will post more later.