I'm a bit late getting my impressions posted, thanks to some extraneous travel, but here goes:
A great thanks to Rob for organizing and running this excellent meet. The space and setup was certainly better than anything I've experienced before at a meet. The after-meet dinner was great, so good we went back to Charleston's on the way home from Oklahoma, so thanks again for that great tip.
I had a great time getting to know a whole new group of head-fiers, and it was very nice to meet you all.
I mostly listened to different headphones that I had little to no experience with, as well as a few amps to get a feel for how they sound with the DAC1. I have come to the conclusion that even the highest-end unbalanced amps do nothing to improve over the DAC1's headphone jack. I orginally formed this hypothesis with Edwood's Grace 902, and it has held true with a Dynahi, as well as the amps featured at this meet. It seems to me that only a balanced or electrostatic headphone has any need for an outboard amp with the DAC1.
I used the DAC1's headphone out to compare cans, using the same music I have played many times at home, so I think I gave them a fair shake.
Headphones:
A900: I didn't like these much at all the last time I heard them (I preferred the HD280's) in fall 2003, but these sounded much better. They do have a bit of glare in the upper mids, but the general balance is nice, with strong bass, a good sized soundstage. I'm not sure I prefer them to the K271S or DT770 for sub-$200 closed cans, but I can certainly understand the attraction to the more than I ever did before.
W1000: These sounded and felt great overall, and if I had the money I think I'd definitely keep a pair of AT woodies around. They take the A900 sound and add more detail and speed, as well as better treble extension, and a better sense of soundstage. They have a smidge less bass though. There is a certain band in the upper mids/lower treble that is quite spiked, resulting in certain songs sounding quite overaggressive, particularly with electric guitar, but for acoustic and classical these cans sound very nice indeed.
DT831: Wow, major suprise here, these are now the top sub-$200 closed cans IMO. They have a better degree of detail and balance than any of their competitors, and great extension in both directions. And of course the comfort is superior, from the DTx31 series, so I really dig these cans. I don't see how people consider these shrill or bright, unless they are of the neutral=bright crowd.
HP3000: A truly unique creation from Larry the woodmaster, and to think he was just getting started at this a year ago! The sound is very detailed, and a touch on the dark side, almost like a dynamic Omega II. Like the OII they excelled with classical music, giving strings a great lifelike seductive character. They lacked a bit in the edginess department (but not to the extent of the OII) so rock and techno didn't please me here as much as on the SA5000. They are certainly top class cans all around, in sound, look, and fit, and if one favors the Joe Grado sound but can't stand Grado (dis-)ergonomics, I wouldn't hesitate to recommend them.
K340: On the one side that had cotton installed, I can see why these cans are highly regarded, as they sounded like a more detailed K501 with BASS. Their soundstage was great, not that different from the K501, considering that they are closed cans. They had a bit of a creakiness to them most likely due to age, but this was only noticeable if walking around.
K501: These sounded about as I expected them to, with nice mids, highs, and soundstage, but a totally unsatisfying bass for any sort of music, IMO. The fit and build is very nice for the price, it's just too bad they are so lacking in the bass (the K26 had better bass performance IMO). If they just had a bit more bass, on the order of the K271, they would have a nice niche.
K26P: I was thoroughly impressed by the sound of these little cans, they are an excellent bargain in the world of sub $50 cans. The ergonomics leave a bit to be desired in the headband, and they felt a bit flimsy, but for the price you can't really complain. They are definite PX100 killers.
AKZip's recabled MDR-V6: Whatever he did to these cans, they were actaully listenable, a comment I could not make about unmodified V6's in the past. The upper midrange hump was tamed a bit, and the lower mids were brought out a bit, making them sound a bit more balanced. Nice work!
Amps:
Ray Samuels Hornet: Not quite as transparent as the top end home amps, but darned close for a sub-credit-card sized package. I think Ray got this one just right for the portable market, small enough for almost anyone who isn't a shuffle-user
Ray Samuels Stealth: Just as transparent as the great solid-state amps (Dynahi, Headcode, Grace 902, etc.), I couldn't find any fault with how it handled the signal from the DAC1.
LaRocco Headcode: Beautifully built (but inevitably a fingerprint magnet), and greatly powerful, with the transparency one would expect of a top-end amp, without the heat of the Dynahi, nor the maintainence of tube amps, the headcode is a real contender in the realm of high-end unbalaced amps.