This amp has another clever Rick grille cutout, in the shape of a capital “R.” A successor in design to the Pro 12 models featured above, the M-11 and M-12 designations continued to apply to both styles of amplifiers despite external design and other differences. This example features the “Rickenbacker” badge on the upper left front and the rare Permaflux 12” speaker, date code prefix 395; a metal screen protects the speaker front. According to one source, the speaker for this amplifier was designed by James B. Lansing, who later founded his own sound equipment company.