Mr. Astor,
I think you're in the minority on that. Could you explain why early '70s 6H30s sound markedly better than 6H30s made today?
BTW I've never had a leaky tube.
Couple of things - I cannot, and will not attempt to argue with a statement such as "sounds markedly better". Such is opinion. Do enjoy such - but such has no standing in terms of science and engineering at all.
A lot of the NOS furor is about nothing more - imo - than some folks who have invested in some old, worn out, tubes that are 60 years old - or 40 years old. Yes they sound different - but if you test them on a full up tube tester you will find that they are merely - well they are old, leaky, worn out tubes. Their sonic difference is more of a tribute to their poor performance than anything else (this is very strongly true in terms of output (power) tubes).
As for you claim that you have never had a leaky tube. Please. Every tube you have ever owned has been leaking from the day it was manufactured. The only question is how much it has leaked (you do know about "getter" correct?).
Vacuum tubes are leaky and by their very nature degenerative. They begin to wear out the moment they are powered up. They do not get better nor are they able to maintain any matching they might have been subjected to. A clumsy and sloppy technology. Sweet sounding at times - granted. But terribly inaccurate.
Tube guys - Luddites one and all.
Puhleeze spare me the condescending attitude. So in your little world, just because it's new, it's got to be better? Because it measures better, it has to be better? It's painfully obvious that you've never spoken to anyone who has had dealings with the Russian tube manufacturers. Nor anyone involved in tube manufacturing in from yesteryear. And over the years, I've never found any particular tube measurement to have any bearing on how the tube sounds. Tubes can measure perfect and have lost dynamics.
You should also do a search here for the the post on the Russian tubes from a quite renowned microphone manufacturer who
details the issues with Russian tubes, particularly the coating issue. You should also talk to the manufacturers who find that the rejection rate from Russian tubes is just as great, if not more, than older tubes. Or how 3/4 JJ Russian tubes failed w/in 100 hrs. Or how these wonderful tubes go noisy within a hundred or so hours. Or just simply DIE for no reason within a hundred or two hours. Where's all that wonderful engineering statistics that you so want to quote now? Oh BTW, never had those issues with older tubes.
Now if you want to argue that most tubes that are sold as NOS are just OS, that's another thing.
As far as the leakage. You know darn well that I was referring to testing with everything from a Hickok to a George Kaye to a Tektronix tube tester.
And my question is still waiting to be answered. Or haven't you ever compared NOS and new Russian tubes. Or any tubes? And in what equipment. Personally, I don't care if you prefer the newly minted tubes but right now it seems like you're trying to be the teflon man. Or ever compared a Telefunken 803S, 802S or 801S (or plain Telefunken ECC83) to any newly minted tube. Or for that matter early Tesla ECC83s to new JJ tubes. Or a Mullard CV4024 to any 12AT7 currently made.
No we're basically stuck with having to use Russian or Chinese tubes by default.