What does this mean? If anyone could shed some light on this, I want to know if there is any point in spending extra money on whatever this is. (I am referring to the menu that I have open in the picture)
It is what it says. They test and find tubes that match the options you select. If you want hi gain tubes, they test for them, if you want them matched, (which preamps usually don't need) then they'll test out tubes until they get a matched pair, and so on.