How do you test different tubes?


I hear people recommending different brand of tubes for amps, preamps, etc. My question is how are people doing this? Are there dealers who loan tubes like other gear? I would hate to have to purchase different sets of tubes, try them, find the one I like best, and then trying to sell the set I don't like.
bryans
I concur that there are legitimate vendors as named above along with the Tubedepot & Tubemonger that you can get quality new in box NOS tubes, and at reasonable prices which normally to my ears sound a lot better than the new production.
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NOS tubes are definitely available. Here on Audiogon I regularly see people selling off NOS tubes from their collections that they realize they will never use.

There are crooks out there so you have to be careful. It's best to have a tube tester if you are going to buy NOS or used tubes and buy from someone who will allow returns.

If you don't want the hassle of learning about tubes and tube testers, the tube sellers noted above can get you top quality tubes for a price.

IMO, NOS tubes can make a difference in the sound of your system that is worth the price.
Viridian: Please let us know how your "giant" Sylvania works out. I'm really curious to know how you came by it and at what cost!
NOS last longer, and NOS sound much much better than currently manufactured tubes; they cost more for a reason. Read other threads on this subject and you'll discover why we buy NOS tubes as opposed to current manufactured tubes.

NOS stands for New Old Stock, and when I buy from a reputable tube dealer, I assume that is what it means. I've bought tubes from the same dealer for years, and considering the short life span of current tubes as opposed to the long life of NOS, I've gotten my money's worth.