Yes, the term means trying different tubes in your equipment. It's a really nice way of tuning your gear, but it can get expensive. That's why as with any other upgrades have an idea of what you're hoping to gain from the tube switch and read the discussion forums. There is a lot of good tube info here. Good luck!
What Ellery likes to roll ain't tubes, heheh.
What Ellery likes to roll ain't tubes, heheh.