Tubes for a pre stage... matched NEW or unmatched identical NOS?


I have this question for so long:

On a integrated amplifier that uses a pair of 12au7 tubes (or alternatives) on the preamp section (Rogue Sphinx, for example) what is best option:
a) to have an unmached unbalanced pair of identical NOS tubes
b) to have of matched balanced pair of modern tubes
c) to have balanced 12au7 tubes no matter if they are matching

Once asked JJ why they didn’t offer matched 12au7 type of tubes and the answer was the it is irrelevant for the kind of use they are intended in audio circuitry. Is this right?

My question only makes sense when forced to keep tube-rolling costs down (or tube substitution when the stock ones fail) because the obvious and better choice is matched NOS, like those from Amperex or Mullard.

audiofilo123

Agree with  @vthokie83 RCA Clear Tops are a fantastic tube at an amazing price.  Way better than any new production that I have tried

Just dropped (2) RCA 12au7 "Clear Tops" in my Line Magnetic DAC. Pleasantly surprised - they are terrific so,... I agree with the hype 

I think many of you know that Brent Jessee is one of the most reputable providers of NOS tubes out there. He will have one of the largest selections, and the tubes go through a rigorous testing before being sold.....and he warrants all of his tubes for 30 days, and many for up to 2 years (not sure of the difference)

This link will take you to the best page I have ever seen on 6DJ8/12AU7/6922/7308/ECC88/E88CC/CCA/6N23P(Russian)/etc. He explains the difference in tube suppliers and their country of origin, and what to expect sound wise from each version of the tube, even how to translate date codes to date your tubes. NOTE: He focuses mostly on Euro tubes, with some information on American and Japanese tubes as well. It's a long read, but should definitely be bookmarked and printed out for future reference....especially for tube rollers.

http://www.audiotubes.com/6dj8.htm