Park P50B Super Bass (1968)

The Super Bass was built to handle bass and then adopted almost immediately by guitar players, Billy Gibbons among them. It was Jim Marshall's first amp to use a solid state rectifier, and it carries slightly heavier filtering than the standard P50. Both changes push in the same direction: no rectifier sag, a stiffer power supply, and a more immediate, tighter feel under the pick than a valve-rectified plexi gives you.

Circuits in this family varied constantly, so which amp you copy matters. Park's reproduction is based on a JMP Bass (Model 1986) built around 1968 - specifically the one owned and played by the late Dan Achen of JunkHouse, which was the go-to house amp at Catherine North Studios in Hamilton. Four inputs into two channels can be run separately or jumped for more range and saturation, PPIMV lets you drive the power section at a volume you can work at, and Mitch Colby's two push-pull pots add an upper mid boost across both channels and separate bright cap values.