Call it what you will - overdrive, fuzz, growl, dirt, snot (yes, this really is a term) - the magnificent noise of electric guitar signals being intentionally distorted through amplifiers has been a fact of life since at least the 1940s.
Overdriven/distorted guitars react VERY differently when played - the increase of sustain and addition of harmonic/inharmonic overtones gained has defined the signature instrumental tone of guitar rock since basically forever, appearing in various levels of extremity and modes of production that differ wildly both between and within more sub-genres of music than we’ve got time to list here today. And we’re willing to bet that at least 50% of people reading this article were first inspired to plug an electric guitar into an amplifier purely to see what would happen when they cranked the entire rig up beyond the limits of its clean tonal ability. Trust me, I’m one of them!
But where did the use of distortion originally come from? Why does it have so many names? And how the hell does it work? As always, we’re here to help you with the basics!
The Science (sort of…)
Disregarding the more modern methods of upsetting the clean signal produced by an electric guitar (pedals, digital effects etc), the three main original methods of obtaining a distorted tone were….
Yes, this is where the term ‘Overdrive’ comes from. Amplifier circuitry, whether tube or solid-state, generally has a threshold of just how much input signal it can ‘gain’ from the source (i.e. your guitar). Breaching this threshold will take a valve amplifiers tubes beyond their normal rated maximum limit, and a transistor amplifier beyond its DC voltage power supply rail limitation. In either case, the result is ‘clipping’ - a waveform distortion occurring where the output voltage/current exceeds the amplifiers design capability. Easy to understand - right?
This one is far more straightforward to explain! Speakers, like amplifiers, are designed to operate up to a maximum rated power. Any attempt to push more power through a speaker than it is intended to handle will, unsurprisingly, result in degraded performance. The output of audio breaks up, producing a distorted sound.
Damaged amplification equipment
The simple and classic method. Slightly suspect power supply? Loose or faulty valves? Or just a damaged speaker cone? These factors, whether accidentally or intentionally inflicted upon amplification equipment, have all been used to great effect by guitar players seeking a distorted sound throughout the years.
All techniques listed above were instrumental in the fairly diverse development of how guitarists adopted distorted sounds, in an enormous range of genres from the outset.
Intentionally powerful pickups were run through small, low-fidelity amplifiers for a ‘dirtier’ sound by the likes of early bluesman Buddy Guy. Later players like Chuck Berry and Willie Johnson were early experimentalists with deliberate gain increase, and Paul Burlinson intentionally dislodged one of his amp tubes prior to laying down The Train Kept A-Rollin with the Johnny Burnette Trio. Link Wray was poking holes in his speaker cones in the late ’50s, whereas Dave Davies took a razor blade to his for the recording of You Really Got Me. And amplifier legend Jim Marshall started modifying the circuitry in his company's famous products for better distortion possibilities in 1966, largely as a result of witnessing Jimi Hendrix maxing all the controls on his own Marshall (infamously referred to as “the Hendrix setting”).
How Do I Get This Sound?
In this day and age? Through a wonderful variety of methods! For example…
Amp overdrive: We’re talking about good, old-fashioned overloading of your basic rig here, produced without any additional equipment. Achieved either by upping the input gain to achieve your required level of dirt (and then keeping it on a leash with the output volume control), or simply maxing out any amplifier until it screams. Either way, the sound produced can best be described as ‘traditional’ overdrive.
Overdrive/Distortion effects: These are most commonly provided by stomp boxes or multi effects pedals, and more recently through built-in digital effects actually built into many amplifiers. The original audio signal is manipulated, either thorough analogue or digital circuitry digitally, to produce a very controllable amount of growl that will work at any volume level. This is also where you’ll find the clearest distinction between the terms ‘overdrive’ and ‘distortion’, particularly on any unit that allows both options; distortion effects generally allow a fantastically unsubtle increase in the level of overall sonic filth compared with what you’d usually be able to achieve through amp overdrive alone.
Fuzz effects: Exclusively achieved through using stomp boxes, multi effects, or built in amplifier effects units, but subtly different to anything termed ‘overdrive’ or ‘distortion’. Fuzz attempts to recreate the sound originally achieved through damaging amp equipment, with an unsurprisingly huge sonic palette usually available to roam through (anything from a mild buzz to noises that go beyond even extreme distortion!)
So What Should I Use? Overdrive? Distortion? Fuzz?
Depends entirely on what you’re playing….
Blues and Rock’n’Roll: The majority of blues AND most earlier styles of rock’n’roll were actually pretty clean-sounding, right up through much of the early ’60s (the Beatles weren’t exactly Metallica remember…). But Elmore James, Chuck Berry, Gene Vincent and many others were more than happy to take their amps just to the edge of their clean abilities, and sometimes a reasonable way beyond. So we’d suggest sticking with the merest hint of simple amp overdrive here.
Straight Rock: Amp overdrive is king here, particularly if you’re maxing out a single channel Marshall for true authenticity! A fine balance between input gain and output volume should satisfy most aspiring rockers, and there’s plenty of pedal options for those wishing to explore the possibilities beyond what your own rig can offer. Fuzz effects also come into play for this genre, especially for the Kinks or Cream fans…
Metal: Extreme distortion all the way, without question. Which will probably need something beyond what a mere amplifier can achieve. Fortunately, a smorgasbord of utterly insane distortion options awaits you at your nearest good guitar shop.
Jazz: Why are you even reading this article?
Wrapping It Up
And there you have it – a simple overview of what distortion is all about, where it came from, how it’s made, and when to use it. We’ve said it before in “Guitar Amplifier Using Your First Amp”, and we’ll say it again; experimenting with overdrive is perhaps the most fun a rookie guitarist can have with their rig – so go and play right now! Until next time...
... Peace out!