The Sunn Musical Equipment Company was formed by Conrad and Norm Sundholm (bass player with the Kingsmen) in 1965, in Tualatin, Oregon, USA. Effectively Norm Sundholm was unable to find a bass amplifier loud enough for his early sixties performances, leading him to create a bass amplifier more suitable for the ever-loudening bands of the time. These early Sunn tube amps are very well regarded indeed.
The company soon sold to Bill Hartzell, who started producing solid state amplifiers, but, as was the case for UK amp producer Vox, the move to solid state technology was seen as a retrograde step amongst potential customers.
Sunn was finally purchased by Fender in 1985.
Vintage Sunn adverts - Sunn had some really high profile musicians endorsing their amps, including Jimi Hendrix, Buffalo Springfield and John Entwistle of the Who