I think that there is a confusion of semantics here. Carlos is, I think, talking about bridging a stereo amp to provide more power for a single channel. Some amps are delivered from the factory with a switch to allow "bridging". I am showing my ignorance, perhaps, but I do not think that that is the same think that Atmasphere is referring to. Take this with a grain of salt, because I know nothing about circuit design (but I do know that the tube amps he mentions sound great).
