I had read on a number of audio forums that swapping the factory vacuum tube in the PreSonus TubePre with a vintage USA made tube would improve the sound quality, more specifically making it much warmer. So I did the research to find out how to dismantle my TubePre, and looked at the specs to find out the exact size and type of vacuum tube that it uses (12AX7), and then set out on eBay to find a new-old-stock vintage GE tube.
Changing the tube is a very easy and quick process and will no doubt come in handy at some point, as vacuum tubes eventually degrade and die. Was this mod worth it? Did the vintage tube magically give me the Voice Of God? Would my singing now sound like a choir of angels? Did I even notice a difference? Meh… Not so much.