This single word can be used to define two different products. First off, the term “head” is most often used to describe the amplifier in a 2-piece amp/speaker combination. Typically, the head sits “piggyback” (for lack of a better word) on top of a matched 1×12, 2×12, 4×10, or 4×12 cabinet. The first known example is very likely a tan Vox AC30 built in 1960, but by 1961, Fender had taken a number of its best-selling combo amps and turned them into piggybacks. These included the Bassman, Bandmaster, Tremolux, and the Showman. By the end of 1965, another British manufacturer, Marshall, began offering 2-piece head/cabinet combinations, which would eventually become known as “stacks” because most players ran a 100-watt amp into two 4×12 cabinets, one sitting on top of the other.
The term “head” may also refer to the Gretsch Filter’Tron and HiLo’Tron humbuckers first introduced in 1957 at the summer NAMM Show. According to Gretsch literature, the “Electronic Guitar Head” filters out hum, neon noises, crackle, and electrical disturbance.” By 1958, Gretsch had dropped the Dynasonic line of pickups and began using its own designs.