In the historical timeline of guitar effects, long before pedals of any kind were commonplace, the effects that guitarists utilised were mainly built into their amplifiers, namely tremolo and reverb.
Fender is the company most of us associate with those onboard effects. Tremolo – a cyclical change in amplitude manifesting as a rhythmic pulsing – debuted in a Fender amp, the Tremolux, in 1955, albeit wrongly labelled as ‘vibrato’, which is actually pitch modulation. Fender introduced spring reverb later on with the standalone 6G15 unit in 1961, and had it built into amps from 1963’s Vibroverb onwards.
