Not quite the era we're talking about, but I'm sure you've had occasion to play through one of this British gent's amps or echo effects at one time or other in the past...

Charlie´s company, Watkins Electric Music (WEM), starting in the early 1950s, eventually manufactured and ran P.A. for the Beatles, Dylan, the Rolling Stones, the Who, Fleetwood Mac, Cream, Pink Floyd, Led Zeppelin and countless others.
His equipment and sound is captured on rock movies such as Pink Floyd's Live in Pompeii, the Stones in Hyde Park and Live at the Isle of Wight where Jimi Hendrix played one of his last big shows.
His Dominator amps and Copicat tape echo units were standard fare in the 60´s and 70´s, and initially, he was the only one either side of the Atlantic (with the possible exception of Bob Heil of Heil Sound here in Illinois) who knew how to bring sound to the massive crowds of the time.
The only other alternative was the primitive "foghorn style" public address systems prevalent in the stadiums of the time in the USA and Europe which were obviously not designed for the reproduction of live music.
These days Charlie is involved in accordion tuning and midi.
I speak to him occasionally (he's a Peterson customer), and his stories are fascinating. You can read about his achievements on his website http://www.wemwatkins.co.uk/history.htm
Another unsung hero who never quite got his due...
Rupert Neve & Joe Meek likewise in the recording industry.
To quote Charlie; "The rest is everybody else's history."
John N.