Someone above mentioned the Fender Vibroverb. The vintage ones from the 60's cost boat-loads, and some find the reissues lacking the great Fender tones. Solution? There are a fair amount of Vibroverb clones out there. I lucked into a home-built one that's wonderful. Loaded with a JBL D-130, which is a terrific speaker in that amp. Do a search for Vibroverb clones and see what you find. Good stuff to be had.