For this “small” AC/DC show (normally the band packs stadiums), Angus was using nine 100-watt Super Lead Marshall heads. About four or five years ago the amps were modded with a master volume control to get a bit more preamp gain. The band tours with Simon Murton, a full-time amp tech, who spends every day in his workshop swapping tubes and doing maintenance because they push the heads so hot that they generally only play three to five gigs before visiting his workbench.