[Freo-1]

"Used up" NOS tubes, and NOS tubes that have seen better days are not New Old Stock tubes in my opinion. They are just somebody else's used tubes. I believe this is the real trouble with "NOS" 12AX7s,,,, there just aren't any left. 400 bucks can buy you the hopes and dreams of days gone by and the wonderful stories told, but probably not a real pair of good ol' day Telefunken unobtainium.

I prefer the Gold Lions. They sound good, they seem to last, and they are real. What more do you want? Buy them and support the factory that makes them so they can stay in business. Or would you rather Paypal some dude on e-Bay to get his used up tubes?

Not quite accurate.  However, I do get your point.   

You can get real NOS tubes from some reputable dealers, such as Radio Electric Supply.  Or, you can get real 7058 tubes for less than the Sovtek made, British branded reissues, and get better performance to boot.  All 7058's were made by RCA back in the day.  I just bought a boatload of 7058's, and trust me, they are truly NOS.  Best of all, they were very inexpensive, and they DO sound good!  Very clear and quiet.

Sadly, once the word gets out on these, they will also become scarce and expensive, so get them while you can.

[underdawg]

I would need to check but I think the 7058 is a little different drawing current and maybe different voltage. I am not sure 20 a pop is cheap, so maybe the word is out.

[Freo-1]

I would need to check but I think the 7058 is a little different drawing current and maybe different voltage. I am not sure 20 a pop is cheap, so maybe the word is out.

Where do you get 20.00?  I see them from 6.00 to 15.00, depending on where you look.   They are a 12AX7, all made by RCA, designed for use in car radios.  The spec sheet states they work from 12 to 15 volt filament, the only issue is they do not have a center tap.  So, as long as you are using a 12 V source (preferably DC), they work great.  Unlike the 5751, they actually are a 12AX7.
Still cheaper than the Russian knock offs.

[JakeJ]

Well put, Quiet Earth.  I would also add my .02 to the clarification of "NOS".  It is, in fact, an acronym for New Old Stock.  Next we have ANOS and it means Almost New Old Stock.  Then there's UOS for Used Old Stock.  You can find these terms used on some tube vendor websites.  True NOS tubes in original boxes (preferably sealed) are rare and expensive.  I think there are NOS Telefunken and others out there it just depends on how deep your pockets are.

Mine aren't so it's good to know that there are some current production tubes that do perform well for those of us that need 'em.

Hey, SET Man, so what brand are these "cheap Chinese 12AX7A tubes"?  What vendor did you get them from?  And most important, what did you have to pay for each one?  TIA

[Freo-1]

 The points about NOS, ANOS, and UOS are quite valid and should be explained to those not aware. 
Now, having said that, took a quick look at 12AX7 prices, and here is what was found:
1)      The Russian 12AX7 tubes with the British name are 172.00 a quad at a reputable tube dealer. Not exactly cheap. 
2)      NOS Telefunken are 75.00 at another reputable dealer.  Also not cheap, but at least it’s the real deal.
3)      NOS 7058’s are 8.00 to 15.00 dollars at reputable dealers.  If your application supports them, then it’s a no brainer compared to current tubes.
4)      The going price for used/tested Telefunkens via auction is 35.00 to 40.00 a tube.
If you own equipment that is current, then I would agree that using current tubes makes some sense.  If you own vintage gear or went DIY, it may make more sense to seek out NOS/ANOS tubes.