VAC 70/70 III Owners......6SN7, 300B Recomm.

Thanks so much Bigshutterbug for responding! Anyone else have any experience they would like to share?

I have a pair of VAC Phi 70s and I like the sound so much I wouldn't touch the factory tube configuration. Then again, I'm biamping a pair of B&W Nautilus 801s using the Phi 70s for the uppers/midrange and a Krell integrated for the woofer. I'm using the 8 ohm taps out of the Phis (I tried the 4 ohm given the complex impedance curve of the 801s but the sound was ever so slightly polite and recessed compared to the other, so I switched back). This is a pretty nice setup, with a very open and airy top end (compared to solid state) that I don't find at all "romantic" or "lush". Maybe its not trying to use the tubes for the low end? I don't know.

My favorite 6SN7 combination, in my vac 70/70 mk3:

in this order:
--black glass KenRad, vt231 (6SN7GT): big deep sound, without sacrificing air
--black glass National Union vt231: very similar to above, maybe a bit softer, darker
--TungSol black glass, round getter: great tube, balanced, big sound, but not as big as KenRad; quiet.
--Sylvania VT231: sparkly, extended, but too bright with my speakers (Martin Logans). this might be the best tube with another speaker.
--GE 6SN7 GTA ... this is a great tube, well balanced, no major outstanding fault, and much more reasonably priced than the others (but also, lacking some of the magic of the above)
--electroharmonix... OK, kind of sterile, edgy.

300b
--The Golden Dragon's sound good in this amp! but,
--I liked the JJ 300bs even better... these sound GREAT in my amp. great extension, powerful sound. check out Eurotubes on the internet for good prices.
--don't waster your money on Western Electrics in this amp, I've tried them, and honestly, preferred the JJ 300bs. The JJs had better extension. The Western Electrics just didn't seem all that special, so I sold them, got most of my $$ back.

I recently purchased a VAC 70/70 mk3 s. where can I find more information about the tubes diagram for the amp? I know it uses two 6sn7 per channel. Are there any differences in functionality between the two 6sn7 used for each channel? For example, do I need to use a matching pair of 6sn7 per channel?

I have one matched pair of RCA red base 6sn7 and a matched pair of Raytheon vt231 6sn7. Can I use one RCA + one Rayheon vt231 for each channel? Thanks.

   "Can I use one RCA + one Rayheon vt231 for each channel? Thanks."      Yes and that's preferable, compared to using the exact same tube, in both positions.