Personally I can't stand their music, but just last week I saw him on tv discussing his tones and his current setup to change them live...there's some kinda monster controller doodad that routes the signal in different ways to multiple amps/effects that are essential for certain sounds of the studio. It's like a whole bleacher (sports park benches) full of amps and racks all tied with patch cords and I think it stays offstage as well.