For the Who's first tour of the USA in 1967, instead of their usual Marshall stacks, John Entwistle and Pete Townshend used Thomas Organ "Super Beatle" solid-state amplifiers. The Super Beatle was the made-for-U.S. solid-state version of Vox's AC-100, which Pete had used in 1965. Even though Thomas Organ owned the rights to distribute Vox in the U.S., they began designing and building their own "VOX" amplifiers, albeit of inferior quality. The amp line was coined the "Beatle" to purely to take advantage of Beatlemania, though the Beatles reportedly used the Super Beatle on their last U.S. tours.
The reason for the difference in gear in the 1967 North American shows was because the group could not afford the cost of importing their full gea , because of their financial constraints, Chris Stamp, the Who's manager, signed the group to an exclusive agreement with Vox to use their gear in the States. The first use of the amps saw John and Pete each playing through two Super Beatles during the Murray the K shows in March/April 1967. They also used them at the Monterey Pop festival; Pete recalls "Kit didn't want to pay for us to bring our own equipment over. We used Vox equipment and sounded dire. Then after we'd smashed it up, Jimi Hendrix came on with big Marshall stacks, set fire to his guitar and completely upstaged us."