Sorry for delay, I think I may have overcommitted myself to a concert going experience - 12 concerts in 24 days, not much time is left - since I also have to put in full day of work 5 days a week. Last week did a 1700 mile road trip for 3 concerts, got 3 more concerts this week and 5 more next one... But let's get back to the battle of the giants. It was a bloodbath, some results were a complete surprise, some were a "no duh" kind of experience. The important part - I didn't walk away empty-handed... My main target was Sennheiser HD820, I was hoping it would be a clear upgrade to Pro 82, and was prepared to buy it on the spot. I auditioned it through HDV820 (used as DAC/Amp), which in my mind meant that this combo should provide the best sound, after all Sennheiser created them for each other. So synergy should be off the charts, right? I bet you have noticed the italics on "hoping"... HD820 was a complete disappointment, especially from HDV820. Bass quality ranged between songs, sometimes too dry, sometimes too hallow, sometimes perfect. Pro 82 is much more consistent. Vocals often sounded shouty, especially male ones. Both male and female vocals had the wrong timbre, too colored. Soundstage is quite big, larger than Pro 82 Imaging isn't as good as Pro 82. Transparency - not even close, Pro 82 rules. I didn't feel present at the concert venue, music always felt like a reproduction. Comfort - HD820 feels very comfortable at first, but after 1.5 hours I felt the pressure on my cheeks. Pro 82 takes this one. Then I tried my Oppos as DAC/amp instead of HDV820. Through Oppo HA2-SE and HA2 HD820 sounds more lively, but vocals are still off (although less). On HA-2 the timbre is almost perfect (HA-2SE has a colored amp). Bass quality is much better! How is this possible? How can a 300$ battery/USB powered DAC/Amp produce better bass than a desktop 2400$ DAC/Amp, specifically tuned for HD820? What kind of magic is that? Using Ha-2(SE) as a DAC with HDV820 improves the bass further, timbre improves too - imperfect still, but close - as good as from HA-2. Looks like the main problem in HDV820 is the DAC part. It's supposed to be some kind of a Sabre chip, but it doesn't sound like one. It was too heavily tuned - I guess Alex Grell wanted to stay away as far as possible from the original HD800 signature with elevated highs, so he toned them down and raised the bass. Best timbre I was able to achieve from HD820 was with HA-2SE + 02 (bass was as good as from HA-2). With or without O2, the Oppos destroyed HDV820 when driving HD820. Pro 82 still has a clear advantage in transparency and timbre, no matter what combination of DAC/Amp was used. Conclusion: HD820 isn't the better version of Pro 82, it's not even in the running. It looks much better than it sounds. Of course, it offered no competition to L300 and Perun either. I'll post other comparisons later (not today).