What tubes to use for Audio Research SP-9 MkIII?

Upscale won't sell any decent 6dj8/6922 types to people unless they bought their gear there. I'd recommend Amperex as the best tubes of this type...after all, they invented the 6dj8 frame-grid type of tube.

-Ed Sawyer
(Full disclosure: I have some of these for sale.)

I second the AR tubes having owned the SP-9 and they do sound their best with tube dampers.

In my experience ARC ls16,sounds best with the stock sovteks.Tried siemens69229-detail NO bass) & matsushita's 6dj8,(no improvement just noisy)I think ARC preamps are sensitive to nos tubes in general,besides the rip-off factor is too high dealing with these "internet guru's of tubes".

My favorite tube in the 6DJ8 family is the Telefuken E188CC.
It is very detailed and laid-back (if this is the sound you are looking for). Siemens CCAs has more bass, and Valvo E188CCs is detailed but a bit forward. Amperex made many differnt types ranging from 6DJ8,6922,7308 Bugle Boys,PQ,USN,CEP,Gold Pin,World Globe,pinched tubes,made in USA, Hollad A getter& D getters (BTW D getter tubes are mellow sounding tubes)

Anyway, all this is quite maddening. I agree with Wlutke, these tubes can get very expensive, and Ebay is a good source to obtain some of these tubes for a listen. Good Luck!

BTW, here are the US and European equivelent #s for these tubes. 6DJ8-ECC88, 6922-E88CC,CCa, 7308-E188CC, the E288CC european tubes are physically longer in length and have a longer life span. There are also US JAN and British CV military tubes as well.