Why do old tubes sound better than current tubes?

IMHO the blanket pronouncement "NOS tubes always sound better than new production" is the mantra of salesmen and the deaf. That they can be, for sure. But as often only have that potential if they actually are any good, as in not used up and/or noisy.

More importantly it is ALL about utilization and tone. Their use is not needed if they don't actually improve anything or give you the tone you're looking for.

FWIW, I use a lot of tubes and I get good mileage out of new production tubes as well as NOS and often actually prefer them, especially on a cost/benefit ratio.

FWIW

Tvad, Forgive me for not writing a book about my stuff and tube experience. No one would be interested, even you. Talk about a cost/benefit ratio! :-)

However if I see a post where I can knowledgably recommend a specific new production tube to get a specific result I will do so without regard to whether its old or new. And that is likely the only time I'll ever get into a discussion on the internet about what tubes I like (or not).

I was really doing nothing more than advocating that those who would come here seeking advise take less than very specific advise in response to very specific request with lots of cynicism. A poster should keep a mind open to all possibilities, including that in many applications new (or recent) production tubes can be, or are, as good as he needs in that specific application. IMHO, 'general' rules, broad observations, and general recommendations suck. Now for someone who can't do better than ask for 'What's Best' I'm sure that generic responses would be fine.

BTW, I realize that you have posted that you have not improved on NOS tubes in the applications you have changed tubes in. I take you at your word. But, consider for a moment that this statement really means little beyond the needs of your applications and the number of new (or recent production) tubes you tried as an alternative. Not so many I think IF you have been predisposed to a conclusion based on the age/expense/rarity/ of the tube or the hyper critical application you were using when you reached your conclusion.

Ciao

Tvad, You are right. I did read too much into it I think.

New production (or recent productions) I have found a place for:

SED 6550, SED EL34, SED 6L6GC, and SED KT88's (I really like SED's)

Re-Issue Tung-sol 6550 (in one amp)

JJ and NOS Tesla 6922's and JJ and NOS Tesla 12AX & 12AU7's. I like the NOS tesla's better, but not that much and they are hard to get and can be spendy.

EH6922's (one application so far - not universal by a mile).

Re-Issue Mullard 12AX7's (one application so far)

EI 12AX7E (long grey plate) - my go to NP 12ax7 as a starting point/reference. I really like this particular EI though I guess it is out of production. I've had no QC problems with this one either.
EI 6DJ8 but it is not as quiet or rugged as I like. Again it is no longer in production.
EI 6CG7 - the only new one in production. So far so good but I'm just starting an inquiry into this tube type for a specific amp but so far so good.

And, FWIW, I've got a few others that are still trying to find a good home. Curiosity may have killed the cat - so far I'm only limping! :-)