Jim McShane says basically the same thing but it doesn't apply to most consumer audio components including Manley. Jim references the Vox AC-30 and AC-30 clones; guitar amps that run the output tubes beyond dissipation specs. I know this to be true as I own an early 1966 Vox AC-30; bad ventilation to make matters worse. Guitar players call this design the "easy bake oven".