Chicago Musical Instruments (CMI) purchased Gibson in 1944 and owned the company until 1969. In 1967, Gibson stopped producing amplifiers in Kalamazoo and production of all amps was moved to Chicago. CMI, Norlin, and Gibson all marketed amplifiers after 1967, but they were never produced by Gibson in Kalamazoo. Not much is known about individual CMI models, but they are generally budget model solid-state amps. Any information can be submitted directly to Blue Book Publications. Source: Walter Carter, Gibson Guitars, 100 Years of an American Icon, and George Gruhn and Walter Carter, Gruhn's Guide to Vintage Guitars.
Chicago Musical Instruments. Amplifiers produced in Chicago, IL between the late 1960s and early 1970s.