I use a Headbone to switch between a Marshall 6100 and a 5150, going to an attenuator, then speakers. Sometimes one sometimes two 4x12. Works like a charm and I've been running mine for about a year. It does not affect my tone, and incidentally I run it through the normal input. The buffered input DID change my tone and I did not like it. I use the buffer in the RJM Rack Gizmo anyway which sounds really good. I suggest the attenuator as it allows me to leave the masters for my (3) amps set relative to each other. I can also run the heads in their sweet spots, which is loud, but still have the ability to turn down when necessary.