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
Ken Rad Black glass discernibly better...Huge depth, expansive, quieter, low level detail more natural, harmonic decay improved, Homeric bass, even more organic while still clearer into depthfield without any increase in sterilty. Sounds very similar in all parameters - as you would expect - but involve-ability is heightened, making any deficiciencies at the frequency extremes (full toward plummy bass in some systems; slight rolling at very top but not thin, just reduced projection) a non-issue IMHO.
No, haven't tried any 5692... but I'd be curious to hear your opinions on them. Have an opportunity to get some National Union black glass... think I may wait until I get the preamp that needs a 6SN7 before I invest anymore in 6SN7s. The kenrads are really awesome...
Asa, the characteristics you're describing seem very much like the differences I hear between Sylvania VT-231s and the clear glass Ken-Rad VT-231s I'm currently comparing. Are you saying that the black glass Ken-Rads have even more of what you're decribing over the clear glass? After trying the Ken-Rads for a week, it's a little tough listening to the Sylvanias, they seem more detailed, but also quite thin in comparison.
D_t_m- the 5692 & 5691 are more neutral sounding and usually
have a lower noise floor and are less prone to vibration.

If you get a chance check out the RCA brown base.