I'm busy and fading out — but I'll try to write some impressions and more tomorrow as time permits.
The RP33 and NKK-02 each has its own strengths … but the RP6-DQ is a big step above them, and it's amazing (and was said) that it matches very well with a wide variety of phones. We were all hoping to hear the RP6 with jjcha's Qualias, but he had to bow out at the last moment — so we have more to look forward at our next gathering — including Jahn's Tower of Power … and maybe some 701s.
I also brought a very well burned-in Hornet which I had hoped to compare with jjcha's AE-1 and SR-71 … but same issue, so that's ahead as well. The Hornet has roughly 400 hours on it and the sound is vastly improved over the early hours of play. It still retains its bold character, speed, impact, great leading edges but also beautiful decay, wonderful inner as well as up-front detail and extension without irritation — but also with much greater imaging, spatiality, separation, placement, smoother highs, more balanced spectrum bottom-to-top and very rich harmonic structure.
Although I really like the RP6 — definitely a winner and a real jewel for Machead to enjoy, I feel the NKK-02 compact tube hybrid (heard with two excellent ElectroHarmonix 12AU7/ECC82 tubes) offers excellent value, and presents a lot of musical information for a reasonable price. It is not warm or "tube-y" and it's got speed and sparkle as well as good midrange texture and pretty good spatiality. It matches beautifully with the HD600+Blue Dragon cable (my favorite), DT880 recable (HiFlyin9 cable) and HD650+Equinox. The K501 doesn't do so well with the NKK-02 and RP33.
The RP33 (dual mono solid state) has a very smooth, warm sound for a solid state amp. It's got a very, very wide and deep soundstage, good bottom end and a smooth if somewhat soft upper end. Some listeners seem to prefer it immediately — I believe because it's got a character that's plush and seductive to a lot of audio "palates", much like the HD650. The NKK-02 (and the RP5.1 which we no longer have available to compare) are less grandly spacious, but have more top extension, speed, texture and rich detail. The NKK-02 and RP5.1 are tougher to match with phones. The SA5000, for example, sound too harsh or exaggerated on top with these amps, whereas it's beautiful the RP6-DQ — as I expect the Qualias will be.
The NKK-02 and RP6-DQ have a 10mm thick slab of nicely milled aluminum up front and BIG KNOBS (slick and glossy on NKK-02 and RPP33, and brushed on RP6-DQ). The RP33 needs the 10mm thickness rather than the thinner front panel it has (too flexible and less luxurious/tactiley satisfying).
Oski played a fun Surround Sound Sampler (from Ultrasone) through his B&W speakers and we heard really surprising surround effects from the 2-channel setup. More wonderful sound from Machead's "Stereophile Editor's Choice Sampler".
The RP6-DQ did a very nice job creating a similar illusion with the Senn phones (via the X-Ray's X-Ray transport … now Machead's transporter). The RP33 and NKK-02 also presented the FX well.
The EarMax Pro was warmly satisfying as usual and traded favorites with the RP6-DQ, depending on the recording/phones combos. K501s sounded very nice with EarMax and RP6-DQ … as well as The Hornet, though obviously less bass impact than the DT880 and Senns. Am drooling to hear burned-in 701s (350+hours...! … someday). The DT880/EarMax combo is wonderful and something I could listen comfortably to for many hours. For my taste I feel even more enthuastic about the HD600+BlueDragon/RP6-DQ for an easy-breathing, refined, rich, smoothly extended, perfectly controlled and defined, quite and subtle, big and dimensional sound.
The matured (well-toasted) Hornet (heard via Titanium Powerbook G4 > iTunes Apple Lossless (Arturo Sandoval Live at the Blue Note, Alison Krauss+Union Station Live, Norbert Kraft "Complete Music for Solo Guitar", Leonard Bernstein's "Candide", some Bill Evans...) sounds very rich with the Senn 650 & 600 (for home), excellent with the HF1 (how good depends on type of pads … HF1 owners will have to add details), a marvelous match with the 501s, and even with the modest folding and noise-reducing Senn PXC300s — which is wonderful since portability is the prime purpose of the tiny Hornet. The PXC300s reduce steady background noise enough to enjoy the music (traffic, ambient big city street sound, buses, motor vehicles, trains, jets, noisy offices, fans/air conditioners...). They don't isolate/attenuate like the better IEMs — voice and transients come through, which is good for safety and sociability — but they've saved me from major headache on a flight on which the engines were shockingly loud for a couple of hours while the pilot put the pedal down to pass a big, nasty storm.
The Rudistor amps were the main purpose of the meet and the results were very productive and really satisfying.
And — as always — it's great to spend time with good friends, having fun in a common pursuit. Would have been a perfect afternoon if Machead and I had succeeded in getting Tangy Sourdough loaves at Amy's Bread — but alas 'twas all sold out!!! It's all good — our appetites were satisfied with bags full 'o great sound.