Noble, on the volume knob being tight: mine too at first. I think its the change in humidity from AUST to here and the wood expanding. Its loosened up over time. I also treat the wood weekly with a quality furniture cream (not oil).
Noble, I also have a AirTight amp with Syrah, and the Syrah shows that the AirTight is not as complex in harmonics as it should be (and outfitted with NOS Mullards and WE300B's it should be very complex). This is a house sound I believe with AirTight and many other Japanese tube amp makers; the Jap tube market, drawn also to the dynamics of horns, IMHO tends also to give a little up in core harmonics to get that dynamic projection quality (AudioNote Kondo IC's/Spkr wire have same dynamic/harminic balance/signature).
Aside from changing amps, I have worked on the Syrah tube complement. I ended with Tungsol round plates for the 6SN7, but could easily live with the Black Kens. Also, the rectifier effects sound appreciably; I have an RCA-marked Coke bottle Mullard in there now and find it far superior to the 6 or so others I tried. The past Supratek distributor sent me this one, so if you want to know about it he's probably the best place to start (I'll send you his e-mail if you contact me). On isolation, bwhite I'm sure is correct, but I have mine on a Rix Rax stand I designed and it doesn't seem to matter after that. However, airborne-sourced tube microphonics have been significantly effected by tube dampers. I tried several and in all locations and the Shun Mook small valve resonators on the rectifier and on each 6SN7 did the trick for me, and especially versus others on the harmonic/naturalness issue. I just got a matched pair of Tungsol JAN 5881's and have been running them for about two weeks. My impression is very sweet, has led to slight melodic integration (better playing together, so to speak, again one of the AirTight's small weaknesses) between players, and even between hands on the piano, but dynamics compressed and voice has lost some presense, in sense that projection qualities of voice are diminished. Image size slao diminished, and too much. Hard call, but even with my marked toleration for lushness, I do not like compression. We'll see, but I think the image issue will break their back eventually.
I owned a CAT MkII for a year, so can't comment on the Ultra differences with Supra, but I always found the CAT resistant to changes/mods/rolling etc. That's good for most people, but I like to have some latitude to go farther. As I said, for many guys out there, and considering the phono that might get them into that, its a no-brainer, in that context. And thats what excited me.
Still would like to hear from you guys on PC's if you worked that at all.
Good luck.
