Introduced in 1964, the AC50 amplifier emerged in response to the increasing demand for louder amplifiers, a trend driven by the British Invasion era of rock and roll live performances. Among the most prominent users of the AC50 were The Beatles, along with several other British pop-rock bands active in the mid to late 1960s.

The development of the AC50 began in the summer of 1963, reaching an advanced stage, if not completion, by autumn of the same year. This timeline is evidenced by an advertisement in a 1963 issue of "Beat Monthly." The AC50's introduction in 1964 marked it as a key amplifier of choice for many iconic groups during a pivotal era in rock and roll history.