My H combo just came today. Had about half an hour to play it and it sounds awesome! It should only sound better as it gets broken in I'd think. Great cleans and the perfect gain channel for my tastes.

How does the effects send and return volume knobs work? Where is a good setting? Half way? Full bore? Does it lessen the gain as you turn it down, or is it strictly volume? And what are they for? I've never had an amp with them. They don't seem to just change effects plugged into the send and return, so what do they do?