All the vendors that I use double test their tubes before shipment and offer some meaningful DOA warranty. Of course, I also test all my own tubes prior to use as well.
I'm sure there are examples of when it's worth paying for and worthwhile in general but I think the basic idea is that unless the vendor is working closely with the buyer and the buyer is also knowledgeable that more often than not it's wasted $$.
It's funny you'd say that, I've had more than one tube vendor tell me not to bother matching tubes because of the inherent non-linear behavior and the fact that they would be matching them at vastly different operating points compared to my application.
It's my understanding that it's highly unlikely that a tube tester is testing the tubes at the same voltage levels experienced while the tube is in use.
Try this link if you want to read the article that Reks linked to.
http://www.nytimes.com/2008/05/30/nyregion/30bodies.html?scp=9&sq=bodies&st=cse
and if that doesn't work try logging into the Times site with:
username: mrfixit5
password: mrfixit
And Reks, that does make me feel quite a bit different about the exhibit as well.
Yes, I can understand that there are some folks who don't use it for valid reasons. But all I can say is that if you don't you'd better be prepared to offer some assurances to prospective buyers. I mean all the guy had to do was say, "Here's a link to my Ebay profile. Please feel free to send me an email through their system to prove my identity so you can feel more comfortable sending me an MO for $XXX."
I can't believe that he made the amp so that it's possible to connect the power cords that way. With the Menace, although it uses the same connectors for all of the power connections, it's impossible to hook it up wrong due to the sex of the connections used at each end. It wasn't hard to do and was a definite design consideration along with making sure that the HV was never exposed on male pins to limit the chances of cooking myself.
Tubes can certainly make noises as the metal inside expands as it heats. I have one set of tubes (outputs) that take a good 30 minutes to heat up to operating temperature and stop making noise.
Agreed, it's one thing if the person is a known quantity but in this case the seller made no mention of payment terms until we were well into discussions about purchasing. All of a sudden it was like, "Hey, how about adding $10 for shipping and sending me a MO? How about no.
Not sure why it'd happen with an input or output tube but it's not all that uncommon with rectifiers, especially if you're running them near the max plate current. The Menace has been known to have a little lightning show in its rectifiers at startup.