It was introduced in 1964 to meet the growing demand for louder amplifiers during the British Invasion era of rock and roll live performances.
[1] Most notable performers that used the AC50 was The Beatles as well as several other British pop rock bands during the mid to late 60's.
The later MKII and MKIII models have 4 channels to meet the varied input needs of musicians.
[3] The AC50 many times accompanied the amplifier head with a speaker trolley cabinet loaded with Silver Alnico or Blue Alnico speakers and a Goodmans Midax Horn to push more bright clear sounds out into large crowds.
With the most popular models being produced by Jennings Musical Instruments, or otherwise known as JMI.