How electronic engineers helped create rock and roll

The problem was easy to state, but damnably difficult to solve: how to make guitars louder?

It was the 1930s, and musicians struggled to be heard when playing onstage with louder instrumentalists like drummers and horn players. The very shape of the acoustic guitar, including its soundboard and hollow body, had evolved over time to provide natural amplification to the notes struck by the player. But new forms of popular music in the 1930s—particularly big band and swing—thrilled audiences by featuring powerful brass sections. Guitarists struggled to be heard when playing onstage with brass players.


This guy had it rough

Playing in front of a microphone presented its own challenges, because it often gave rise to painful feedback loops. Starting in the late 1920s, manufacturers like the Stromberg-Voisinet company began to produce amplifiers for electrified string instruments. Magnetic coils placed beneath the strings captured their pitch when struck, converted it into an electronic signal, and conveyed it to an external amp to increase the volume of their instrument. These early amps used electrolytic capacitors and glass rectifier tubes, and solved the volume issue for many musicians.


Vintage Vega amplifier, circa 1930


But wait, I hear you protest. Isn’t this supposed to be about music effects pedals? Why are we talking about amps?

To understand the evolution of pedals, it helps to begin with amps, because when musicians discovered the accidental qualities amplification imparted to their sound, they began to seek these effects as an end in itself. Initially, guitarists were told to match the signal of their instruments with that of their amps to provide a clean increase of volume without adding much coloration or distortion to the instrument’s sound. But by the 1940s guitarists were beginning to experiment with the magnetic coils (or “pickups”) on their instruments to alter the sound being sent from their instruments. Buddy Guy and Elmore James were among those who sought to match the rawness of blues singers such as Howlin’ Wolf and Muddy Waters by modifying the pickups on their instruments.


Elmore James soundhole pickup

By the 1950s, a new wave of experimentation had began. Guitarists were deliberately overdriving their amps to produce new kinds of tones—tones impossible to produce in a non-electrified setting. Willie Johnson, Joe Hill Louis, and Chuck Berry all recorded songs using overdriven, distorted sounds. Describing the origins of his 1950s guitar sound, Pat Hare explained that he turned the volume knob on his amp “all the way to the right until the speaker was screaming.”


Guitar pioneer Pat Hare

This was not what these devices had been built for. From the moment new technologies were introduced to help guitarists, they began hacking them to produce strange new sounds to take their playing to unimaginable places.

A defining moment arrived in the 1960s when Dave Davies, guitarist for The Kinks, produced a new type of distortion by hooking the already-distorted output of one amp into the input of another amp. This daisy-chaining produced a hitherto-unknown level of distortion which heralded the birth of hard rock in the 1960s.


Contemporary daisy-chaining. The instrument is directly connected to the Fender amp on the left, and this amp feeds directly into the Gibson amp on the right.

Then, in 1966, a frustrated guitarist left New York for London. His scant belongings testified to just how hard his life had been in America: a small bag of clothes, plastic hair curlers, acne medicine, and $40 were all he had to his name.

That, and his prized Fender Stratocaster electric guitar.

His name was James Marshall Hendrix, and within a few months he would change the face of music forever.


Jimi Hendrix’s passport photo, 1966