Kind of a weird question, yes. I know these amps are commodity fare, and no one expects much from them, but are there any basic changes that can make them sound a lot better than they do out of the box? Specifically I had heard that they could be changed from 6L6'es to 6V6'es but I don't know much about that. Is that just a tube swap? What has to be done to make that happen? I also wondered if putting better speakers would make a difference, or getting speakers that have had pre-rola doping done to them and putting those in. Anyone done this? Thoughts?