Tubes for my Mac's 275....NOS or just used?

I am getting close to getting some telefunken tubes for my Mac 275's. I will need 12AX7's and 12AT7's.
What is the difference between NOS and just used? I know there is a saving to buy used but has anyone purchased used with success??


Rick (RWD)
Used are used and NOS is Old stock but un used....There are plenty of good NOS tubes around..You just need to know the House sound of each type you need..Each one sounds just a bit different so you should buy from an expert tube supplier...Don't buy Ebay junk,you may be sorry if you do.......
Agree w/Thorman -- if you do not have a tube tester -- stay away from those who sell vintage plates and dolls in addition to tubes (just using an example & have nothing against vintage plates nor dolls).
NOS is supposed to mean New Old Stock, new meaning zero hours (brand new).

There are tubes that fit this description but not as many as advertised. Many sold as NOS are in fact used tubes. That being said, used tubes that test new are typically low hours, test equipment pulls or test spares. Many of my tubes are used and bought at great prices.

If you want NOS and willing to pay top dollar, Andy Bauman at Vintage can supply them, just be prepared for a long wait. He is meticulous.

As for Ebay, a good many of my hundreds of tubes came from Ebay and generally I've been treated well. Unfortunately you have to know tubes before you can shop Ebay successfully as there are about 20 levels of quality there every day.
I've purchased the majority of my NOS tubes on eBay, or from eBay contacts over the last 5 years. All the purchases(probably 40+) were excellent, but for one(if you e-mail me, I'll let you know his user name). I got four counterfeit Telefunkens from him. Anyway- The majority of tube sellers on the 'Bay are upright and knowledgable(especially the German ones). You just have to know the right questions to ask to find them. Don't buy anything from those sellers in Asia. they are expert counterfeiters. If you visit here, you'll find a comparison chart that indicates what kind of sound to expect from various 12AX7s: ( The flavor of the 12AT7s manufactured by the same companys will be similar. If you like transparency, lack of colorations/microphonics, no phoney mid-range warmth: try the Siemens and Telefunkens(from the 60's).
Rick, I thought you'd already retubed your 275's. Still running those OEM time bombs? The correct term for used vintage tubes is ANOS (almost new old stock) NOS should be reserved for brand new tubes that at most have only been powered up for testing (but nost sellers are just a little sloppy about that.)

OTOH, really unused, but old tubes, can be uncertain performers. They can have developed leaks, or become gassy (which only shows up after they've be run for awhile) or have internal damage (that causes shorts to happen but maybe not right away.) So sometimes (slightly) used is better -- like with used cables that have already had some break-in. Most of the vintage tubes I've bought have been used, but tested new both for transconductance and remaining life, so I'm not concerned about their performance. Let me put it this way: I've had bad tubes test 'good', but never a good tube test 'bad' ;-)

You don't trust eBay thorman? OK, so what's your point? You either take the time to educate yourself, with or without a mentor's help, so you can buy/bid with confidence or resign yourself to paying at least 3 times more (and up) for the same thing from a tube seller. And you stand a better chance of finding what you want faster on eBay.
Nsgarch: It probably wasn't a fair statement about Ebay junk..I have done many good tube deals on Ebay..My point was for a newby or Someone that might seem new to the NOS scene,I think it would be the smart thing to buy first from a relaible ( but more expensive ) tube dealer,thus having a better chance of getting exactly what he might think he is getting..I just think there is a higher percentage of satisfaction that way ..As you did mention.The best thing any potential tube guy can do is " his or her Homework " ...I know we all have put our time in and it does pay off down the road.........
I have purchased tubes before (from Andy) etc. and I do understand the meaning of NOS. However, a big thank you from me for your help.
I would like try to keep the cost down so I though going to e-bay may be good.
If I do, sightly used is OK? I would also think so...right?
Any of you have success with anyone in particular on e-bay? In other words...are there any regular tube dealers on e-bay.

P.S. Neil, I am getting there...(slowly).
I just bought 4 new Telefunken 12AX7's at Ebay for $164.00. That's $41.00 apiece. I've seen current production 12AX7's for that much.

I've had very good luck with Ebay, look closely at product description and seller feedback.
Thanks particular what should I be looking for in a used (or even NOS) tube Telefunken?

Please, all respond if you can offer advice.


Rick (RWD)
My advice is seek out a seller that has a reputation for selling tubes with lots of positive feedback.

Be sure specifications are included in seller description such as test results and remaining life and maybe a money back guarantee offer?

Photo's should be in ad, showing general condition, markings, condition of pins and the embossed "Diamond" on the base, surrounded by the 9 pins.

Small signal genuine Telefunken tubes will have this embossed diamond. If not, it was built by another (NOS) producer and sold to Telefunken (rare but possible) or counterfeit.

Counterfeit is unlikely with the best tube sellers, these guys know the difference between tubes, some even read the manufacturer codes and include date and location of construction in the description.

I have almost zero problems with buying tubes like this, the only exception is VERY sensitive locations such as the first gain stage of a phono. This is an especially vulnerable spot as signal from this point on is magnified thousands of times by the time it reaches the speakers.