Even if you know hardly anything about the frenzied years of Beatlemania, you probably have at least a vague image in your head of tens of thousands of screaming fans – overwhelming the sound of the Fab Four's live performances.
Technology, in every facet of life, has obviously advanced light years in the six decades since, and the world of onstage guitar amplification is no exception.
There was no such thing as an arena or stadium touring circuit when the Beatles took over America in the mid-'60s, and the band's onstage guitar amp rig was laughably inadequate in the face of the sheer volume of the hysteria that greeted them wherever they played.
In a 1997 interview with Guitar World, George Harrison reflected wryly on the band's live situation, remarking, “We used 30-watt [Vox] amps until we got those really big 100-watt amps at Shea Stadium. And nothing was even mic'd up through the P.A. – they just had to listen to our amps and the two vocal mics. Sometimes we'd just play rubbish.
Source: Guitar World