NOS and modern tubes

Most of us "know," or at least think we do, that a high-quality NOS tube from the 1950s-early 1970s can't be beat by any of the new stuff in terms of sound quality and longevity. Feel lucky and rich if you can't tell the difference.
Yes, a quad of KT-88 or TS 6550s from the early 1950s makes a dapper noise.
But without getting into the Ford/Chevy thing, I have a simple question. If money were no object, could a production valve absolutely identical to the originals in metallurgy, SQ, labor skill, etc., etc., even be made? If not, why not?
I've been writing about the hard-rock mining industry for McGraw-Hill's Metals Week for the past decade and a half and trust me, there's no shortage of PGMs, minor metals, precious metals, rare-earths, critical metals and carbon anywhere in the supply chain. Metals are not very democratically distributed in the earth's crust, but any can be found if the price is right.
Assuming the metals haven't flown the coop and are still around, what's another variable that prevents a good tube from being a great tube? I refuse to believe that good dies are harder to make in this day and age than they were in the 1940s.
There is of course the labour component, both cost and skill level. Can we not teach to a 1940s skill level with some apprenticeship woven in?
(To peruse Andy Bouwman's collection of old tube factory footage, it was mostly women on the assembly lines, even after the war. Do we need more women at the benches?)
I'd much rather buy a brand new tube over a 60-year-old one, if all else were equal. .
Why the diff? Or am I "hearing" things?

I imagine it simply boils down to craftmanship and Q/A.  There needs to be enough of a market in faithfully recreating vintage tubes to justify the costs of production.  Also, whoever is taking on the endeavor needs to have a real passion for quality and artisanship.

Kind of related, if you haven't seen it, is Dalibar Fany, hand building new Nixie tubes.  It's obvious from the video that there's a lot of pride in creating these.  They aren't cheap.

Video...worth a watch.

No Deepee, you are not hearing things. Your ears are right on! Those NOS tubes were just made to a higher standard in a time when rare earth metals could be implemented into the production of a vacuum tube. My understanding (and I could be wrong on this) regarding rare earth metals, although better sounding these materials are a potential carcinogenic threat to the assembler(s). One of the reasons you simply do not see US manufactured tubes. Another variable that prevents a good tube from being a great tube? Quality Control. Countries where standards are little more loose - Europe, China, former Yugoslavia, Russia etc. rule the roost on current vacuum tube production in MHO.

Reminds me of the original Mad Max movie and sign in the automotive repair shop: Speed costs how fast do you want to go? NOS tubes are not inexpensive as you well know. I too prefer new tubes from a reliable source. Yet, the joy is in the hunt. There are some virtual gems still out there for the taking.

all of the above, and figure an actual price of about 10X of new production tubes, about the same difference as a 69 Chevy VS a 2019 Chevy ($3k > $30K)
So a decent 12AX7, around $150, a decent 6550, around $350.
So a NOS 60s era Mullard for $200 which is what they go for, seems about right.
Makes a NOS 60s era GE 6550A at $250 each a bargain !!

tubes4hifi wrote:all of the above, and figure an actual price of about 10X of new production tubes, about the same difference as a 69 Chevy VS a 2019 Chevy ($3k > $30K)
So a decent 12AX7, around $150, a decent 6550, around $350.
So a NOS 60s era Mullard for $200 which is what they go for, seems about right.
Makes a NOS 60s era GE 6550A at $250 each a bargain !!

Roy, aulde chum . . .
You ever give those mid-1950s-60s 6550 As a trial? Sounded like modern knock-offs; tinny and shallow until the bass chords moved in, then they rocked. I gave my quad a 6-month trial with them and promptly sold 'em for cheap.
You can still find Mullard GZ-33s and -37s for $75 if you're patient.

Tubes produced with current metalurgy and robotic manufacturing probably could easily surpass NOS tubes. Too bad the market demand isn't sufficient to justify the startup cost.

I do not think current new production is that bad. I recently replaced a quad of JJ 6550 that had
accumulated 4325h in a VTA-70, tubes were still working and measured some degradation
but still within spec.
The same amp does eat GZ34, currently on the 3'rd , now i have installed the "yellow sheet" to
see if that helps. If this fails it will be Si rectifiers as next rectifier.

It might be interesting to compare current production materials and processes to a simulation of "what might be", were the level of the standards and practices used in solid state robotic production, applied to tubes. I don't really know enough about current tube production, but have read comments indicating quality varies greatly.

I used an ST 70 I assembled as a kit for over 20 years and a friend used another 20 before returning it. I don't recall replacing the tubes often, but after updating it went through a few 5AR4s quickly. I probably bought less expensive tubes at the time, and probably should have spent more, but decided to use a SS plug in. Our power in Maine can be unreliable, probably partially because the grid is unreliable, and as I recall the tubes went during a few days of bad weather, which frequently brings down lines. That amplifier sits idle now.