Kalamazoo is a budget-brand (house-brand) name Gibson used between the 1930s and late 1960s. Gibson produced several budget-brands over the years, but Kalamazoo is considered one of the more collectible ones, because of the adjustable truss rods used in guitars after WWII.
When the economy was feeling the effects of the depression in the early 1930s, Guy Hart knew that lower priced instruments were going to sell better than the higher priced counterparts. Gibson started to introduced some budget lines that were Gibson-made guitars with a different label on the headstock. These guitars were nearly as good as authentic Gibsons except they didn't have the truss rod (or price tag). Like most Gibson guitars, Kalamazoo was not produced during WWII. In the late 1940s, Kalamazoo was introduced again and was reaffirmed as Gibson's in-house budget brand. The Kalamazoo name went away again in the 1950's as Gibson went through the roof in sales, and didn't need a budget line to get by. Kalamazoo was introduced again one more time in the mid-1960s with a line of electric guitars and amplifiers. By 1967, Kalamazoo amplifiers were phased out as all Gibson amplifier production moved out of house. It is possible some models were produced into the late 1960s at other factories as a 1968 catalog offers the entire line. However shipping totals only indicate amps shipped between 1965 and 1967. Kalamazoo was discontinued for good as Epiphone became the budget brand for Gibson in 1970. Sources: Walter Carter, Gibson Guitars 100 Years of an American Icon, George Gruhn and Walter Carter, Gruhn's Guide to Vintage Guitars, and Gibson Shipment Totals, and Wallace Marx Jr., Gibson Amplifiers 1933-2008 – 75 Years of the Gold Tone.
Amplifiers previously produced in Kalamazoo, MI between 1965 and 1967. Kalamazoo was a house brand of Gibson.

KALAMAZOO Guitar Amplifiers Models

KALAMAZOO BASS 30 Image

KALAMAZOO BASS 30

- 30W, 2-10 in. speakers, bass combo, four tube chassis, preamp: unknown, power: 2 X 7591, solid-state rectifier, single channel, flip-out gray control panel, two inputs, three knobs (v, t, b), black covering, gray grille, 25.5 in. wide, 20...

KALAMAZOO MODEL 3 Image

KALAMAZOO MODEL 3

- ~5W, 1-10 in. speaker, guitar combo, solid-state chassis, single channel, front silver control panel, two inputs, two knobs (v, tone), gray covering, gray grille cloth, 760 shipped, 13 in. wide, 16.125 in. tall, mfg. 1967 only.

KALAMAZOO BASS 50 Image

KALAMAZOO BASS 50

- 50W, 2-10 in. speakers, bass combo, tube chassis, tubes unknown, solid-state rectifier, single channel, flip-out gray control panel, two inputs, three knobs (v, t, b), black covering, gray grille, 25.5 in. wide, 20 in. tall, mfg. 1965-67.

KALAMAZOO MODEL 4 Image

KALAMAZOO MODEL 4

- ~5W, 1-10 in. speaker, guitar combo, solid-state chassis, single channel, tremolo, front silver control panel, two inputs, three knobs (v, i, tone), gray covering, gray grille cloth, 2,528 shipped, 13 in. wide, 16.125 in. tall, mfg. 1967...

KALAMAZOO MODEL 1 Image

KALAMAZOO MODEL 1

- ~5W, 1-10 in. speaker, guitar combo, three tube chassis, preamp: 12AX7, power: 6BQ5/EL84, rectifier: 6X4, single channel, front gray control panel, two inputs, two knobs (v, tone), gray covering, gray grille cloth, 21,387 shipped, 14 in....

KALAMAZOO MODEL 2 Image

KALAMAZOO MODEL 2

- ~5W, 1-10 in. speaker, guitar combo, four tube chassis, preamp: 2 X 12AX7, power: 1 X 6BQ5/EL84, rectifier: 6X4, single channel, tremolo, front gray control panel, two inputs, three knobs (v, i, tone), gray covering, gray grille cloth, 32...

KALAMAZOO REVERB 12 Image

KALAMAZOO REVERB 12

- 12W, 1-10 in. speaker, guitar combo, five-tube chassis, preamp: 3 X 12AX7, power: 2 X EL84, solid-state rectifier, single channel, reverb, tremolo, front black control panel, two inputs, six black with silver face control knobs (loudness,...