Tung-Sol Reissue 6SN7 vs EH 6SN7 - Differences


I ordered a matched pair of the new Tung-Sol 6SN7GTB tubes being made in Russia for my Supratek Chenin preamp and have been listening to them versus the stock 6SN7EH tubes. The Tung-Sols sound a bit fuller in tone than the EH, while retaining the bass and treble extension of the EH - in short, I prefer the Tung-Sols.
Before listening, I examined the two tubes very closely side-by-side, and could not see any differences in construction other than the fact that the Tung-Sol has a black plate and the EH has a gray plate. I was expecting them to sound identical, but I noticed the fuller tone of the Tung-Sol right away. I decided to contact New Sensor and ask them what the difference between these tubes really was.
They answered my email within an hour or so, as follows:

"The Tung-Sol 6SN7 has internal differences. The internal geometry is different and the grids are gold plated."

If we take them at their word, the Tung-Sols are not merely re-badged EHs as has been suggested by some. Thoughts? Anyone else have the same listening impressions as me?
ait
I know - that's what I keep hearing. I'm just trying to find what I like in the current-production world first - NOS is expensive and you never know what you're actually getting from the seller. I'm sure I'll succumb to the NOS bug sooner or later.
By the way, I actually like the dynamics of the 6SN7EH a lot, it just sounds bright/harsh in the highs in my system. The Tung-Sol eliminates some of that brightness, while retaining the dynamics; at least it does in my system.
I also tried the Chinese Sino/Shuguang 6SN7. It is much warmer than the EH or the TS, but the whole presentation is less focused and the dynamics are nowhere near as good. Too big of a tradeoff in my opinion.
It's good there are now two kinds of high-quality 6SN7s from New Sensor within a few dollars of each other. I have NOS Raytheon & Sylvania chrome tops to compare to EH 6SN7 & yes the NOS are better. But the EH are quite good. In many instances the considerable expenditure of rolling NOS tubes might be more wisely committed to circuitry mods that produce greater returns than tube rolling.
One thing I forgot to mention - it seems that the TS like to be driven a little harder than the EH. When I first swapped in the TS, they sounded light in the bass and lower mids. The Chenin is very adjustable, though, so I moved the gain switches behind the 6SN7s from low to medium, and turned down the master level control on the back of the pre one notch - voila, the bass and mids were at least as good as the EH now, with the highs still much more accurate, and the volume control still had the same range. Gotta love flexibility!
I did a similar trial w/ my AtmaSphers MA1s. I had all EH 6SN7s in them for about a year or more. I replaced the 3 middle tubes (considered the most critical, sonically)with TS Reissues. My first impression after letting them burn in for about 20 hours was that they were much more dynamic and tighter in the bass. I began to wonder, though, how much of the effect was due tot comparing them to tubes that had many more hours on them. So I bought some new EH tubes, and tried them out. I put the new EH in one amp, left the TS in the other, and played them for a few weeks before listening cpomparitively. What I heard was that the 2 tube types were extremeely similar. I could not tell much, if any difference, although I desperately wanted to. If anything, I thought the TS were slightly more forward in the midrange, which in my system was not a good thing. I think I put the old EH in for a bit, and concluded that the new tubes sounded very much like the old EH; in other words, the initial improvement I heard with the new TS wore off in rather short order with use. I wanted to spend some more time with these comparisons, since I bought the new EH just for this purpose, but I got distracted with chewcking out some new source components. Ultimately, I got bored with trying to hear the differences between the tubes, because they seemed so slight, once they all had some serious time on them. I would like to go back and compare again, but I'm sick of listening to equipment, and have been enjoying listening to music for a while. I'd love to hear any other opinions on this, especially after your tubes burn in for a while Ait. It's pretty cool that you can vary the gain on your input tubes like that to tailor the sound.
Hi seems like some of this is system dependent.

In my BAT VK75SE (now 150SE) I had RCA 6sn7's. softer on top, little more real, but lost the dynamics and punch and texture of the russian 6h8c's. I ran the RCA's for a year before I went back to the 6h8c's.

Doug: what are you running in your 75SE right now? I'm due soon for a retube, and can't decide on the 6h8c's or the EH's or Tung sols...

Thanks