The sound of the Vox AC30 isn’t just permanently etched in the minds of rock ’n’ roll fans everywhere. Its diamond-pattern grille cloth, seen as backdrop in innumerable photos of the Beatles and countless bands from the British Invasion up to the present, is permanently etched on our retinas. It’s a ubiquitous design used by such notable players as the Kinks’ Dave Davies, Rory Gallagher, U2’s the Edge, Peter Buck of R.E.M., and Queen’s Brian May.
The AC30 got its start in the 1950s. Tom Jennings founded Jennings Organ Company, which produced the Univox—a “piano accordion” that incorporated a three-octave keyboard with a built-in amplifier. Its one-note-at-a-time sound became popular in pubs in post-World War II England. (Check out the Tornadoes’ 1962 recording of “Telstar” to get an idea of what it sounded like.)
But it was the up-and-coming popularity of rock ’n’ roll in the latter half of the ’50s that prompted Jennings to reunite with his wartime buddy Dick Denney to produce an amplifier designed specifically for guitarists.
Fender amps were available in England, but at a hefty cost. Not only did shipping make them prohibitively expensive, they also required a step-up transformer to run on the U.K.’s 220V grid. The AC30’s pint-sized progenitor, the AC15, was born in 1958. Manufactured in Sussex, the “Amplifier Combination 15 Watt” was the affordable answer to Fullerton imports.
It quickly became the 6-string voice of Hank Marvin, guitarist in the popular instrumental group the Shadows, as well as with popular Merseybeat group the Big Three, Lonnie Donegan, and other guitarists—and, yes, accordionists—in the U.K. Its instantly recognizable sound—glassy, chimey, and sweetly compressed when driven—defined early British rock. The AC15’s tube complement—a pair of Mullard EL84 power tubes (or “valves” in British parlance) and a high-gain EF86 pentode in the preamp—were a key difference between the Vox and Fender sound.
But the increasing popularity of rock ’n’ roll soon led to bands being booked in larger venues (never mind the fact that rock drummers were also getting louder). To keep up, guitarists were looking for more volume. Enter the AC30, which doubled the AC15’s power section with four EL84s producing 30 watts of class AB power.
According to Jim Elyea, author of Vox Amplifiers: The JMI Years, Dick Denney’s original single-speaker AC30 built in 1959 featured two EL34 power tubes. In order to work in conjunction with two speakers, however, the EL34s would have required a taller cabinet than what we’re accustomed to today. So four EL84s enabled use of a smaller, more manageable chassis. According to David Petersen and Dick Denney’s book, The Vox Story, the Shadows took possession of the first three AC30s in late 1959. Interestingly, for a short time three versions of the AC30 were simultaneously on the market: the one-speaker EL34-powered AC30, the AC30/4—which had four input jacks, an EF86 preamp tube, four EL84s, and two speakers—and the AC30/6, which had six inputs, a 12AX7 in place of the EF86, four EL84s, and two speakers.
What about the AC34?
Vox fanatics who deep-dive into the company’s history are sometimes vexed by the mention of a mysterious “AC34” design—including on an April 1960 Jennings Musical Instruments schematic. Author Jim Elyea demystifies the moniker for us: “If you say ‘AC30/4’ to someone, it sounds identical to ‘AC34.’” In other words, there’s not some ultra-rare model out there. The “AC30/4” and “AC34” are the same amp. The confusion—apparently even at JMI in 1960—arises from the failure to verbalize the slash mark in the model designation.