***Is It Me Or Have Todays Modern Tubes Gotten REALLY REALLY Good***

I dig the new production tubes. Haven't found any NOS, and I've rolled a handful,  that beat the the modern tubes for my phono stage. My amp and pre amp - that's a different story . 

My experience with NOS tubes has been that as a rule they do not stay quiet as long as the new production equivalents. Perhaps the very slightest loss of "vacuum"?

I won't say which brands of tubes, because I am just one individual, so the sample size is really small and it could have just been bad luck, however...

I decided to try rolling some new highly recommended tubes in my preamp.  About a a month after I got the tubes, one went microphonic.  The good news is I was able to return them for a full refund. 

I decided to try another highly recommended set of new tubes.  One of those went microphonic after a few months.  I contacted the manufacturer and they offered to apply the purchase price of the first set of tubes towards their "new and improved" tubes.  I said sure.  One of those was microphonic when I installed it.  I gave up on that brand also. 

I put the stock Tung-Sol reissues back in and those worked fine. 

I recently bought a pair of NOS  Sylvania 6SN7GTA Chrome Dome tubes to replace the Tung-Sols and those seem to be working well so far.  I paid an extra $13.99 for an extended two year warranty, so if these go bad any time soon, they'll be replaced.  These were also less expensive than either of the two new sets of tubes I bought.

It's too soon to say how these will hold up over the long run, but they're quiet and sound great in my preamp.