[druthafoo]

It doesn't necessarily sound louder but much cleaner. The increased power allows you to run a much cleaner signal to the speakers. When you amp speakers you allow a cleaner signal to come through. When people try to crank their speakers without an amp it sounds distorted because the signal is clipping due to a limited range. The amp increases that range. Crap this makes no sense but imma leave it up so someone can correct me.

That clicking noises and such could occur because of a ground loop.