A friend of mine has unearthed a Sound City 50 Plus valve amp that has been in his loft for at least 10 years. It's a non-master volume amp with normal and bright channels. I'm interested in it, but he's scared of powering it up as he can never remember it being used. It was his partner's son's amp (he moved out 10 years ago), and he knows that the son never had a cab for it, so he may never have used it.
He's had a look inside and there are no signs of leaky or damaged caps. He's vacuumed it out but there wasn't a lot of dust in there.
I've told him to take the valves out first, check the fuses are OK, then fire it up with no valves in and make sure no fuses pop or smoke appears. Then stick the pre-amp valves in and run it again. If still OK, put the power valves in. (All done with the volume off and a cab connected).
I know some people recommend using a variac to increase the voltage slowly, but there is none handy.
Is my start-up suggestion OK? Anything else to consider.