@Clive Harris -- Re: If it's not full of valves...
Presented for your approval (or not; I really don't care): The (original) acoustic 360/370 bass amp [Emphasis definitely added!]. Not a tube or valve to be found anywhere near it, but it is the only amp, living or dead, that has approached my ultimate of standing roughly 10 feet in front of it, hitting the low 'E' string, and having it knock one's feet out from underneath one.