Are NOS tubes Overrated ?

Arj schrieb:

interesting discussion i was pointed out to at another forum http://www.audioasylum.com/cgi/t.mpl?f=tubes&m=15185 any experience our forum members have on it ?

Arj,
I have not read that discussion on AA as yet (but intend to later) however from my limited experience in indulging in NOS tubes the experience *could* cut like a knife.
I've bought NOS Telefunken 6922 & NOS Telefunken 12AX7 (small signal) tubes. I've also bought NOS Tesla 6922 tubes, NOS Amperex 7308 tubes & NOS NIB 12BZ7 tubes. So far I've resisted buying NOS power output tubes.
As far as the Telefunken tubes are concerned - this brand was VERY popular & anybody selling NOS Telefunken tubes has to be viewed with great suspicion 'cuz such an animal rarley exists. However, if you know something about the history of this tube & which factories it was made & which test parameters signify good working tubes then go for them! They are simply excellent sounding tubes - both 6922 & 12AX7 (ribbed plate & smooth plate).
I bought a 7308 pair from a trusted friend but that tube was microphonic from the get-go! Bummer! To save my friendship I bit my tongue.
I bought the GE NOS new-in-box (NIB) 12BZ7 for my AES Sixpac & those turned out to be genuine & simply fantastic as they elevated the sonics of the Sixpac to something I could not imagine.

So, the concl is is that NOS tubes are very good sounding & often worth having. However, some output tubes (Like Golden Lion KT66, NOS RCA 845s, etc) are simply exorbidant & unafforable. Here one has to question one's own application for them, look into one's pocketbook & prioritize before attempting to buy.
So, the lesson here is KNOW YOUR NOS TUBES BEFORE YOU SHELL OUT CASH FOR THEM; otherwise you're likely to get burned.

Tried swapping NEC 6SN7 tubes with 1945 vintage Sylvanias in Siva's new Pre which Abhi had at his place on demo. The difference was so dramatic, it wasn't funny at all. I'd let Abhi tell more about it.

I have plenty of NOS tunes...NEC, Brimar, Mullard, Philips, Telefunken, etc., Anyone willing to pay the premium are most welcome ... will be happy to give it away.

Hey siva

6sn7 in your pre ? I thought you used the 12ax7 and you didint like the 6sn7 at all.

What made you flip ?

Manek

Arj

My experience with NOS has been very good with 6sn7. my new tubes were from electroharmonix and sovtek and they don't hold a candle to my NOS. Gave the sovteks away.

Those guys in the 50's sure knew how to make them tubes.we may have all the specs and all the technology to make em better but there is obviously something missing in the formula. is it materials ? Workers who had that craft ? Tighter tolerances ? Quality checks ? It is said that once transistors and ss electronics upstaged the tubes around the 70's the quality and quantity of the tubes did go down as tubes were hardly used in new prod and were more used as spares for older devices.so there will be a few tubes from the 70's being sold as NOS at a premium.

There are very good re-issues like the tung sol's.As far as tubes are concerned old is still gold if found electrically sound in its specs.In india I don't know of anyone selling tested tubes so its definately a bit of a gamble buying NOS. Most good tube resellers also test new prod tubes before selling them so buying new prod ones may not be that safe either.

Power tubes made today are pretty decent comparatively though.EH, JJ, svetlana do make good power tubes but a mullard is a mullard ! Btw mullards are to be manufactured again.

And yes there are very good mordern prod tubes like there are good yet cheap nos ones. Got to lookout for those bargains. For eg: japs are not known to make great sounding tubes at all but my hitachi 6sn7 is a very good tube. I laughed when my brother told me he had hitachi 6sn7 tubes and liked them over every one he hadbut the tung sols(he had plenty, enough to open a small store). I bought a set only cause I trust his ears immensely and if it turned out to be a dud then I would have something to pull his leg with for years to come(we brothers do enjoy a bit of this). You know what ? They do sound very good. Very even across freq's, detailed....they are NOS but cheaper than the other fabled ones and yet as good or better.

Manek

Manek schrieb:

Hey siva 6sn7 in your pre ? I thought you used the 12ax7 and you didint like the 6sn7 at all. What made you flip ? Manek

It was a one-of-pre...as part of an experiment. That's all.

My own main investment is still on 12AX7. I do not think one tube is better than the other...like many tend to argue. They are at best...different.

:-) would like to hear ur views on both the designs...but I guess you have made your point clear.

Manek

hmm maybe quality control is better now and the newer materials for the filament and the glass used while effective for electrical characteristics are not really musical ?

dont know..the jury seems to be still out on this one. maybe rather than NOS vs Non-NOS the differences might be more on well manufactured Vs not so well manufactured !

Arj schrieb:

hmm maybe quality control is better now and the newer materials for the filament and the glass used while effective for electrical characteristics are not really musical ? dont know..the jury seems to be still out on this one. maybe rather than NOS vs Non-NOS the differences might be more on well manufactured Vs not so well manufactured !

Not really. Many of the NOS you get in the market (I would say ... around 90% of available NOS) are all tubes thrown out after thier useful life in some electronic equipment. It is really not NOS ... but "Used and Thrown Out" (UTO !!)

Regards
Siva.

maybe we call also call them "fully burnt in" tubes

More like fully burnt out !
:-)

Like everything else, must have reliable sources.

Manek

sivat schrieb:

Arj schrieb: hmm maybe quality control is better now and the newer materials for the filament and the glass used while effective for electrical characteristics are not really musical ? dont know..the jury seems to be still out on this one. maybe rather than NOS vs Non-NOS the differences might be more on well manufactured Vs not so well manufactured ! Not really. Many of the NOS you get in the market (I would say ... around 90% of available NOS) are all tubes thrown out after thier useful life in some electronic equipment. It is really not NOS ... but "Used and Thrown Out" (UTO !!) Regards Siva.

I beg to differ, Siva!
Yes, there are a lot of "NOS" tubes parading as "New" old stock when they are actually UOS (used old stock)! For example, almost all of the Telefunken tubes as they were so popular during their heydays. (I noted this in my original post).
However, there are a lot of NOS tubes that are actually NOS tubes. One can tell this by the test parameters. These test parameters do *not* tell you whether the tube is noisy or not OR whether it is microphonic. All it tells you is how much life is left in the tube. Most of the ones I've seen pedalled in the usual tube places have 90-95% of their useful life remaining. To me, that qualifies as a NOS tube. All of the NOS tubes I bought from unknown sellers (i.e. sellers who are not my friends) turned out to be genuine products & I'm still using them in my electronics.

So, like I wrote in my original post, one MUST know one's NOS tube before buying.
There IS genuine NOS product out there. YOU have to do the leg-work & ferret it out.

hi siva,

are you referring to the tubes one sees on online stores with testing offered as used and thrown out? that's a scary thought! or are you referring to tubes one might find at a local electronics store?

regards