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

FYI, I really haven't enjoyed any newer tubes, all of my favorites are NOS. I do use matched tubes for each channel of my 2 channel amp.

For the money, it is very hard to beat 1960s RCA "Clear Top" tubes; you can usually find them for about $20 or so each and they are terrific.

If you want next level it will cost you, I really enjoy Amperex tubes. My favorites are Amperex 7308 PQs, Amperex 7316 "Long Plates", Amperex 6922 PQs, and Phillips 12AU7s.

Thanks to all for all the interesting posts.

It seems that matched is the way to go, but as I don’t want to spend top money on NOS tubes I will to manage with NEW production tubes.

What are your favorite 12au7 type NEW production?

What are your favorite 12au7 type NEW production?

What amp? What purpose? What circuit? What music? What room? What system?

ALL sound different in different places. The validity of most opinions is ZERO.

And after how many hours as they change from first turn on...

people posting seem to be getting confused, referring to 6dj8 tube variants and such, when the op is specifically asking about 12au7 tubes and their equivalents

12au7’s in usa or european old stock form are plentiful and relatively inexpensive, even for well matched sets - no need to play with the relatively grim and unreliable chinese and russian current production when so many nice old stock ones are around

having said this, the 6dj8 types -- especially higher end dutch or uk cca ecc188 variants, what have you, that is a different universe, an entirely different discussion about value, availabilty and affordability

I’ve got a good assortment of these nos premium 12au7’s and 12ax7’s so I match them up as accurately as I can with my Hickok tester and use them that way. I really hear the difference in brand and era but not positive the matching is so critical but most experts would probably do what I do given the choice that I’ve accumulated