The Vox T-60/AC-100 bass amplifier uses two 15-inch cabinets and thirty-to-forty watts of solid-state power using "germanium transistors" [REF].The Sunn Model T was used by The Moody Blues, Kiss, Queen, The Who's John Entwistle and Rush's Geddy Lee [REF].
When the Fender company invented the first widely produced electric bass guitar (the Fender Precision Bass) they also developed a bass amplifier, the Fender Bassman, first produced in 1952.