Why Purchase used tubes?

Warren,

No guarantee, thus buy from reputable sellers. NOS can test new but can be used. Also, tubes I believe don't have a linear curve when it comes to life span. More like dropping off a table.

I buy used to try out tubes to see how they sound in my system. The ones I like, then I buy NOS. It makes no sense to pay hundreds on NOS tubes that end up not sounding good in your system.

Matty

Hey Photon46, I use the same tubes (Amperex Orange Globes) and agree with you that they are a good bang for the buck tube. I bought a quad for my Lamm's and since I only use 2 at a time, I figure I am set for life. They sound more refined than the stock Sovteks.
(I have heard the legendary pinched waist PQ's, in my system, and they did sound great, but not much better than the Orange Globes, IMHO. And at one tenth the cost, I'll stick with the Orange Globes.)

My tube mentor happens to agree with Tvad on the Siemens Cca. Tvad, what type of tubes did you use in your Exemplar Denon 3910?

I only like used tubes to play with. If used ones make a "difference" in my system, then I'll go buy NOS ones. However, some of the best dealers will computer match the used tubes. These will be virtually identical and should sound and wear that way. Try upscaleaudio.com

After reading Joe's Tube Lore on AA, the Amperex 6922 PQ, US (shield, gold pins) sound excellent. The Holy Grail Amperex (same with the pinched waist) are out of my league. Joe says the sonic qualities are very close, however. Also, another interesting thing is going for the 5751 as a substitute for the 12AX7 Telefunkens and Seimens. Anybody with listening experience comparing the two? He absolutely, resolutely says the best of the 5751 kills the Seimens.