70's GBX Bass Driver (Bass Preamp)

Late 60's to mid 70's built GBX Bass Driver. Not a conventional amp head, it requires a power amp and can't drive a regular speaker by itself.  The original GBX speakers had the power amp portion inside of it. 

You can plug it into another bass amp and used it like a fuzz/overdrive effect or use it with a Cabinet with a power amp built in.  The range of tones you can get out of it are pretty impressive, and the five different response types you can select are all pretty different.

History:

Ahed Music Corporation, Ltd. established in 1969, was a Canadian company that produced guitar amplifiers, as well as guitars. Its main product line was the GBX amplifier, which could reach 180 watts with 4x10", 4x12" or 2x15" speakers. GBX was the acronym for "Guy Beresford Experiment". The GBX series was a concept created by Guy Beresford, (now with Yorkville Sound). He worked in the basement of his parents store Kalua Music on Kingston Road in Scarborough, Ontario.

The GBX amplifier had a pre-amplifier head that controlled the gain, brilliance, depth, contour and response of the output. The detailed history behind the GBX guitar amplifier began in 1968 and is in reality the original thought of musician Jim Garrett and engineer Adrian Ball. The objective was to make a solid state amplifier sound like the warm tube sound of Fender and Marshall amplifiers. The secret behind the GBX sound was a coupling transformer separating the frond end from the output transistors.