Charlie Watkins is a British audio engineer and musical instrument maker, and is notable for pioneering loud PA systems for outdoor rock festivals. His company Watkins Electric Music was founded in 1949, but it was in the 1960s and 1970s that "WEM" PA systems in the kilowatt range became standard for British festivals, such as the Isle of Wight Festival (with Dylan in 1969 and Hendrix in 1970) and Glastonbury.
Watkins claims[1] to have been the first to build PA systems with multiple slaved solid state amplifiers driving various loudspeaker stacks, beginning with the Windsor Festival in 1967.
Watkins is also the inventor of the Copicat tape echo machine.