Be sure to check out the July 2015 issue of Vintage Guitar Magazine. On page 38, George Gruhn and Sarah Rose Jones contribute a great article on the Epiphone Professional guitar and amp. The combo, attached by a multi-pin connector/cable, was produced from 1962 through 1966 and featured amplifier effects (Tonexpressor, Reverb, Tremolo) that were controllable by several switches and knobs mounted on the semi-hollow guitar's pickguard. Less than 400 of these combos were ever produced and today the Epiphone Professional Combo serves as a fine example of the innovative spirit at the root of Epiphone's history.
Wondering how it sounds? Check out the Epiphone Professional combo in action below, courtesy of Chicago Music Exchange.