AC100 Head  4xEL34s for guitar/bass + Box1x15"

The AC50

Between 1963 and 1965, JMI enjoyed an incredible combination of success and creative freedom, and the Beatles played a huge role in enhancing Vox’s fortunes. The Beatles started their 1964 world tour using the new AC50 heads for guitar, and the AC100 for bass (both powered by EL34 tubes), but they soon found that playing to ever-larger crowds of screaming fans at the height of Beatlemania demanded even more amplification.

Meanwhile, the requirements by groups for more powerful amps than the AC30 still had to be met. The demand was for more volume and less ìn the way of effects and multiple channellìng. J.M.I 's desìgn team was already fully committed in 1962 with the Continental organ and the various solid-state amp ventures, so Triumph Electronìcs, one of the AC30 chassis contractors, offered a 50-watt design based on cathode-biased EL34 valves. This featured two channels, each wìth its own tone circuít derived from the Top Boost circuit, and seemed to Jennings to answer the pressing need for a high-powered amplifier for all instruments. A cabinet with two higher powered Celestion speakers rated at 25 watts and a Goodmans mid-range horn (worked at treble frequencies for better power handling) could be fitted with a stand and the separate amp unit (Vox model no. AC50) stored underneath. The T.60 cabinet (although slightly mìsmatched) would do for bass instruments. This was the array of Vox amplifiers which powered The Beatles during theìr 1963 and 1964 U.K. and U.S. tours and represented the pinnacle of British music equipment technology at this time.

The AC-100, the first 100-watt amplifier, used four EL34 valves and was originally designed for John Lennon and George Harrison of the Beatles, who began using them on stage in mid-1964. The amps, though rated at 100 watts, were not well suited to the Who’s volume, and reliability — with heads catching on fire — was questionable.

Andy, Jane and Reggy Tielman (Germany 1966)

Led Zeppelin September 7th 1968

Pete in Ca. 1965, with Vox AC100

The Who in 1965, with four AC-100 amps.

http://www.thewho.net/whotabs/index.html

  SCHEMATIC VOX:  http://www.drtube.com/guitamp.htm#Vox