Tube vendors.

@invalid 

The only reason not to call Andy at vintage tube services would be if you can't wait 2-3 weeks for your tubes.

I can wait 2-3 weeks for someone who is so far beyond all the others mentioned on this thread. For someone with far better equipment, testing, and knowledge -- absolutely. 

the best tube supplier is andy's tubes he is on the internet you should check him out.

Vote for Viva tubes. All new tube set for my MAC 240. Very pleased, quick shipping as well. 

the viva shop in mass is good, they ship quickly, communicate very well (sometimes a problem with andy at vts as he is older and essentially a one man show, as is jim m), viva is also very responsive when issues arise with tubes they sell

that said, i don’t believe viva does extra testing in house or burn in on their tubes, which can be quite important and valuable with some tubes for some amps... for new stock tubes i believe viva relies on the factory testing and matching, which for some makes and tubes may not be so great

I purchase new tubes from The Tube Store and NOS from Uncle Kevvy at Upscale Audio. Extremely satisfied with both dealers and shipping is about the same.