Not discrediting the market for digital modelers though; most fans of these systems that I know use them for less wear and tear for tours and gigs on their tube counterparts.
EHX buying NewSensor's factory ensures that tubes will be around for decades, even for this niche market. Plus the NOS market is still one any laymen can participate in.
https://www.ehx.com/blog/peek-inside-one-of-the-worlds-great...
I do think audiophiles trump musicians when it comes to superstitions. Just recently found out there’s a market for cables costing hundreds of euro’s to interface hi-fi components, with lush descriptions of the soundstage afforded by such cables. Ignoring the fact any record one listens to will have its sound passed through 20 euro cables at some point in its production.
I can see something like this being a part of the audiophile attraction to these types of components: that every time the owner adds a new set of magic interconnect cables, magic power cables, or whatever, they imaging that they hear an improvement. In the end, they have a lot of themselves invested in their "rig", as they call them, and so find it easy to hear virtues that aren't really there.
I'm hoping these blokes never crack open the amp to look at the plain old PVC-insulated wiring within. And don't tell them the oil-in-paper caps are fading over time. Ditto with the carbon resistors.
Meanwhile, humidity of the air and barometric pressure has a measurable affect on the sound of paper-cone speakers. How long before an "audiophile" barometric chamber is marketed?
The weakest link always has an effect, as you mention. To some musicians, this is the effect. I.E. Hendrix preferring cheap coily-cables which rolled off the high-end on his Strat/Marshall combination nicely. Now coil cables are a premium.
[1] https://www.google.com/search?q=audiophile+coat+hanger+test&...
Electric guitarists are often poor, clever, and self reliant. They can regularly find themselves out in the boonies with nothing but duct tape and baling twine to hold their rig together. Choosing a more robustly built older amp is not an irrational choice for such a person.
Audiophiles... I don't understand why you want tube amps. They are good for guitar players because of their imperfections (e.g. overdrive, "warmth", etc) which is the last thing I want when I'm listening to a quality recording.
It might be possible, but it surely isn't easy nor obvious. "Instantly," as you claim? Sorry, but I'd bet a sizeable stack of money that's not the case. Perhaps if you're talking about a 20-year-old 1st generation Line 6 Pod or Yamaha Fx500, then okay, I can see that. But modern modeling amps are exceedingly good at reproducing the nuances of a valve amp. The Kempler is remarkable -- I would go as far as to say astounding -- in its ability to reproduce the breakup, compression, warmth etc. of an amp at all volume levels. If you heard one in person you'd be a believer. At the other end of the spectrum, even a $150 Fender Mustang amps does a respectable job of sounding faithful [disclaimer - the factory settings are pure rubbish and almost embarrassingly poor, but tweak the settings in the computer editor and a whole wealth of sounds are available, some of them are brilliant).
And why would someone want a valve amp for playback of recordings? The same reason you claim to hear the "warmth" of a valve guitar amp. The same reason guitarists use an EP3 (echoplex tape delay) with the tape out -- that preamp circuit compresses, clips, and enhances the waveform in a way that is very pleasing to the ear. Some notes increase in clarity and bloom in a pleasant way.
A valve amp doesn't imply distortion. Leo Fender was a radio tech before forming his amplifier/instrument company. He knew the value of having lots of headroom.
The key is blind testing. Everyone thinks that they can tell the difference between a Kemper and a valve amp.
I've posted many threads over the years at TheGearPage, with real amp recordings vs hardware/software modellers, and in nearly all cases, the guesses are just that - guesses, which fall into a 50/50 distribution. That is of course, when the guys who are purported 'experts' actually participate in the polls. Most of them tend to disappear whenever they are challenged to voice in on them.
I have some lovely tube amps here, and I also own a couple of Axe-FX's, and for me, when travelling, the Axe-FX is my 'go to' purely for convenience. At gig volumes, and in a band mix, it is pretty hard for me to tell the difference, and I enjoy the tone the same.
I know a lot of guitarists say that they have to have the 'feel', but for me, the 'feel' is there anyway (I usually feed my Axe-FX through the power amp stage of a real amp). I normally play fairly clean, blues/rock based stuff, and the last gig I flew across the country for, the rented backline actually had a Mesa Rectifier III for me. I've never played a Rectifier style amp before, but I had my Axe-FX, with a Fender Bassman amp model preset, through the power amp stage of the Rectifier, and it sounded amazing. The other bands were asking me how I was getting such crystal clean tones out of a 'metal' amp!
The ode to the way things used to be I think drives this market. Combine that with vinyl and you have a medium and listening experience that's superseded entirely.
Scarcity is a problem. No wonder most Western countries rarely have even small boutique production labs these days - the materials and processes involved are (were) highly carcinogenic, and creates a lot of toxic waste pollutants. I keenly follow Dalibor Farny (mentioned elsewhere in this thread) - he seems to have devised a better way to make Nixie tubes (though not tubes like 12AX7s etc. that amplifiers use).
But one wonders, with the current excellence of amp modellers such as the Fractal Axe-FX and the Kemper Profiler etc. whether soon the digital emulation of that analog tube sound will be enough to finally put the last of the tube makers out to pasture?