Watkins was[1] the first to build PA systems with multiple slaved solid state amplifiers driving various loudspeaker stacks, beginning with the Windsor Festival in 1967.
Realizing the increasing need for guitarists to be able to amplify their instrument for live performances, Watkins experimented with building amplification systems for acoustic guitars.
[2] In 1958, inspired by the Marino Marini Quartet's song "Come prima", Watkins had the idea for a simple, affordable, portable tape echo unit.
[7][8] The PA system was so loud that local residents complained to the authorities, who leveled charges against Watkins and attempted to regulate the volume of the festival.
Watkins also provided the PA system for Janis Joplin's performance at the Royal Albert Hall in April 1969, with the singer announcing to the audience how pleased she was with the sound of her voice that night.
[3] Watkins established friendships with many of the musicians who used his equipment, including Jimi Hendrix, David Bowie, and Marc Bolan.