Father Time, what tubes are in it already? You are moving hastily on the tubes without even hearing them. Just because they're old doesn't mean they don't sound good.

My HF-85 was produced in the 50's/60's. I bought it with the original Mullards, which sound better than most modern production tubes. They have alot of life left, and tested quite strong. Infact, if I were to sell it without the Mullards, and put a typical modern equivelant in, I would get LESS money for it.

There are some great tubes out there, currently being produced, but generally they cost quite a bit.