The Jennings Organ Company was founded by Tom Jennings after World War II and made the Univox, an electronic organ. In 1956 Jennings was shown a prototype guitar amplifier made by Dick Denney, an old workmate from a wartime munitions factory. The company was renamed Jennings Musical Instruments, and in 1958 the 15-watt Vox AC15 was launched. It was taken up by the Shadows and other British rock 'n' roll musicians.
In 1959, with sales under pressure from the more powerful Fender Twin, Vox produced the 30-watt AC30. The AC30, fitted with Celestion "blue" loudspeakers and Vox's special "Top Boost" circuitry helped to produce the distinctive sound of the British Invasion, being used by The Beatles, The Who and the Yardbirds, among others. AC30s were later used by Brian May of Queen and Paul Weller of The Jam.
In 1962 Vox introduced the pentagonal Phantom guitar made by EKO of Italy. It was followed a year later by the teardrop-shaped Phantom Mk. III, the prototype of which was used by Brian Jones of The Rolling Stones.
The Vox brand was also applied to electronic organs, notably the Vox Continental of 1962, and guitar effects pedals, including an early version of the wah-wah.
In 1964 Jennings sold a share in JMI to the Royston Group, and sold American rights to the Thomas Organ Company. He left the company in 1967, at about the time that Marshall overtook Vox as the dominant force in the British guitar amp market. Royston went bust in 1969, and the company went through a series of names and owners. Costs were cut, especially in the production of the AC30: cheaper loudspeakers with inferior magnets were used, as were printed circuit boards, while particleboard replaced plywood and at one point a solid-state version was introduced.
Vox Amplification Ltd has been owned by Korg since 1992, and has released the most faithful version of the AC30 for many years and a new range of digital-modelling amps. Some products are now made in the far east.