Would you buy a tube amp if you were unable to use vintage tubes in it ?

The one thing the JJ’s are very good for is filling the spot when you ship for repair or to sell the gear.   
 

👍👍👍

Yes. Plenty of vintage tubes stored away in cabinets, and using all new re-issue tubes now and past few years.    I rotate the vintage tubes in/out once in a while, just to make it seem like they are all worth keeping, and from some of the best vintage tube sellers & testing, yet not finding much of a need for them as much any more. Just buy quality tubes that are well tested with a warranty and helpful tube seller and you should be good. If you can do both types, great, if not, its not as big of a deal that some like to make it out to be imo.Best of Luck.   

Yes, but i have a tester....  it's risky with 4 pin antique tubes and also any rectifiers though .   Most of my tube gear has modern equivalent or type is still made.   I do have a bunch of e180f and 5r4gy/ 274b on hand so no worries.   

I'd ask the opposite question- does the unit sound good with a modern production tube? Good old stock is depleted and pricey- yeah, I run them but it gets harder to source replacements. And in my experience, there is a big difference in sound among different tubes that are semi-equivalent if not directly equivalent. So, I'd want something that will play nicely with a readily available tube, not just unobtanium, if I were in the market for new gear today. And, what is readily available today may not be tomorrow. I've been using tubes for audio since the early-mid '70s. If I were starting from scratch today, I don't know that I go down the rabbit hole at all, but that's wishful thinking-- I am where I am. Enjoyed the journey. Appreciated the days when you could buy new old stock Tele 12ax7s for 10 bucks a pop-- which was considered a premium. 

I ask this question with complete sincerity.  What is the fascination with vintage tubes?  I can't think of much else where people put such a premium of things built decades ago.  Nothing technological that I can think of.  Are there some materials that are no longer available to modern tube manufacturers?  Is there a secret process that has been Lost?  Surely,  we must be able to manufacture tubes today with the same care and attention to detail.  In virtually all fields, the passing of time leads to improvements in the manufacturing process.  So why are audio tubes, apparently, an exception to this rule.