Buying tubes 2nd Hand

I have purchased both NOS and used (test good) signal tubes from the following Ebay sellers. 1. K1dft and 2. Valves31. All tubes were of high quality (sound wise). If you are looking for tubes for a special application, I will suggest trying to contact them directly with your needs (at least they both made me this offer and I assume that they are open to this). It may take them a while to locate, sort and test the tubes, but everything worthwhile takes time. I have also purchased driver tubes for my amp on two occasions from Longplate @ this site which were VERY reasonably priced and which also sound excellent. He also has tubes that he does not get around to listing. The tubes that I generally buy (Amperex, Mullard & Philips MiniWatt 6922 types and Sylvania Gold Brand 5687's) are fairly easy to ID by the construction, labeling and etched codes (I prefer not the earliest, but the slightly later Amperex white labels with the "O" getter). If I were purchasing other types of tubes however, I would be lost as to dating them. I have seen some Amperex 6922 types on Ebay that do not look right to me, either the tube, the packaging or both (usually the packaging though), so caution is advised. Overall, I find used (test good) tubes to be by far the best bang for the buck, especially if you are experimenting with tube rolling. If I find a good deal on NOS that I am familiar with though, I don't pass them up.

Justlisten: What are you using them in and do you use matched pairs/quads or singles?

Boy, that's a slew of 6922's. I just use one at a time for the input tube on my amp and one 5687 for the driver (the amp has a volume pot). Because of this I can buy singles and the only matched tubes that I have picked up in quantity are Amperex White label 7308's (for a rainy day and a pair of Audion mono blocks if I can ever get around to them).