Steuspeed,
However, in twenty years, if I am alive I will be 75, and I'm not sure how good my hearing will be then...
You can't change amps, cables or tubes. Many in this hobby enjoy the challenge of upgrading and tweaking their system to their taste.I suspect once I get a really great system that I will be happy to just keep it for a couple decades. I don't see myself tweaking it or swapping gear. I would imagine that in a couple decades there will be something significantly better which I will consider.
However, in twenty years, if I am alive I will be 75, and I'm not sure how good my hearing will be then...