Black glass KenRad 6SN7s take the cake


I've been experimenting with 6SN7s in my VAC 70/70:

ElectroHarmonix: good tube! and great for the price. Much better than I though it'd be, but ultimately sounded too edgy and sterile. Good control throughout, and good detail.

Sylvania VT231: twinkly and brilliant; great detail, tight bass, but much less fatiguing than the ElectroHarmonix; nice and smooth, but still lacking in the mids for me.

TungSol black glass, round getter: better than the Sylvania, in that it was a bigger sound. Lost the twinkly and brilliant quality. Good detail. Good overall, balanced tube. Nothing outstanding I thought, relative to the other tubes I tried.

KenRad, tall, black glass: THESE KICK!! very lush, deep, BIG BIG sound; the absolute best midrange; detail was good, and surprisingly, this tube is NOT DARK. very smooth, and less reserved sounding than the other tubes. Let's it loose... and that's the one drawback; the bass isn't as tight the TungSol or the Sylvania, but it didn't annoy me. What I gained from this tube far outweighed this drawback.

...that's just what I thought of these tubes in MY system. Who knows if these qualities translate to other pieces.
128x128dennis_the_menace
Dennis, my impression of the NOS Tung-Sols and Sylvania VT-231s mirrors yours in my Blue Circle BC21. Early this past spring when I was buying up tubes on Audiogon, I managed to snag three NOS US Navy Ken-Rad VT-231s dated January and February 1945. I've enjoyed the Sylvanias so much that I stopped rolling the tubes in my BC21, but I've always wanted the qualities you describe in the Ken-Rads. The Ken-Rads will be going in my Blue Circle right now, I'll report back in a few days.
Dennis-have you tried mixing the 6sn7s you have? I have a VAC 30/30 and spent considerable time rolling different 6sn7s I have, many of the types you comment on above. I find most of your comments on the money. In my system, the best combination were the sylvania Vt-231s on the inputs and the Ken Rads on the outputs of my 30/30. Give it a try, you may find it to your liking as well.
Pgleekel... which of the 6SN7s are the inputs, and which are the output? Has anyone tried the National Union black glass?
KenRad black glass are extremely fine. I have four NOS 1944 matched pairs, army boxes, that I am still glad I accumulated at the time. I use the Tungsol round getter black glass, but only because speakers in that particular system are not full range (Tungs sound sweeter there, although not as expansive as Kens).

You guys may want to take a look at the "Preamp of the Century" thread. The Supratek pre takes 6SN7's and we discussed them there about a month ago. My impressions and others are there FYI.

denis, what tube did you eventually end up with as outputs on the 70/70? Svets? Happy?