Kalamazoo Amplifiers
At the same time Gibson introduced the Kalamazoo guitar, they also began production of a line of Kalamazoo amplifiers. They were marketed primarily as budget model practice amps to supplement the marquis. The first amp introduced, the Model One, began production in 1965 along with the guitars. It was followed in 1966 by the Model Two. Both used vacuum tubes for power, rectification, and output. Both had roughly a 5W output and a 10" Alnico speaker manufactured by Chicago Telephone Systems (CTS). The differences between the two were few, with one major exception. The Model 2 was equipped with a tremolo circuit tube to accompany the volume and tone controls shared with the Model 1. The Model 2 proved more popular with this extra feature. The last of the Model 2's produced were given a brown, wooden finished face in place of the usual black panel. By present day standards, these models are not as desirable for use with guitars. However, they are fairly sought after by blues harmonica players for use in amplifying their sound with microphones due to their natural distortion and harmonics. However, the relatively small output and the naturally higher frequencies of the EL84 power tubes usually lead the Model One and Model Two to be used for practice or performance in a smaller setting.
Around 1969, solid state versions of the Models One and Two were issued in very limited numbers. They were succeeded thereafter by the Model 3 and Model 4 respectively. All of these amps used semiconductors in place of the vacuum tubes. These models, while novel in their day, ultimately proved unpopular.
The Kalamazoo Reverb 12 was introduced as a larger, more powerful amplifier, boasting a 12W tube driven output through a 10" speaker. The Reverb 12 featured a tremolo circuit like the Model 2, but with depth control along with frequency. The tone was managed by individual bass and treble controls as opposed to the single tone control on earlier models, and boasted a spring reverb, a feature not offered on other Kalamazoo amps. It also differed from the previous Model One and Model Two in the respect that it used solid state diodes for rectification instead of a vacuum tube. The Reverb 12 has often been favorably compared to the Fender Princeton Reverb amplifier, despite the differences of solid state versus tube rectification, and using EL84 power tubes rather than 6V6 tubes.
Gibson also produced Kalamazoo bass amplifiers. The tube-driven Bass 30 and Bass 50 were both equipped with a pair of 10" Jensen speakers, a flip-out control panel that became flush with the back of the cabinet when not in use. The later models of the Bass 30 were configured in an upright cabinet as opposed to the typical horizontal cabinet, and the flip-out panel was dropped in favor of controls on the top face of the amp to better match the later Model One and Model Two appearances. The Kalamazoo Bass (with no number attached) was usually made in a solid state form, although some specimens have been found to be equipped with tubes.
Read more about this topic: Gibson Kalamazoo Electric Guitar