Overdrive, Distortion, and Fuzz Guitar effects all result from the waveform of your electric guitar's signal being "clipped." Clipping occurs when the tops and bottoms of a waveform are cut off, or diminished in varying degrees. Clipping effects are considered desirable by many guitarists, and used frequently in many genres of music. This article will give you a general understanding of the mechanics and history of clipping as it pertains to electric guitar sound.
Definition of Clipping
A signal without clipping gives a “clean” guitar sound, while harsh clipping results in a “fuzz” sound. Varying degrees of smooth clipping, in which waveforms are rounded off (instead of chopped off like in fuzz) results in a range of effects from light, amp-like overdrive, to heavy, metallic, distortion. Asymmetrical clipping occurs when the tops and bottoms of a waveform are clipped in different ways.
How can clipping alone result in so many unique overdrive, distortion, and fuzz tones?
Your guitar signal does not contain just one waveform. The complex sound produced by an electric guitar is the result of many fundamental and harmonic waves. Each wave can be clipped in many different ways, resulting in a virtually infinite amount of possible guitar tones!
Where in the Signal Chain Does Clipping Occur?
Clipping can occur in preamp tubes, power amp tubes, speakers (drivers), and in any pedals in the chain. Clipping associated with speakers and tubes is more likely to occur at high volumes that push these components to their limits.
History and Origins of Electric Guitar Distortion
Distortion in electric guitar sound was initially seen as a negative, and many early amplifier manufacturers prided themselves on their low-distortion amplifiers. Soon, however, many guitarists began to appreciate the overdriven sounds that their cranked up vacuum tube amps could deliver. The overdriven sound that was once discouraged became sought after, and designers began intentionally incorporating overdrive into their amplifiers.
Additionally, guitarists and guitar companies began finding other ways to create the pleasing overdriven sounds that they desired. Some players slashed the cones of their speakers to create a fuzzy sound. The first guitar pedals, all of which were simple fuzz effects, began to emerge. One early example of this is Keith Richard’s famous use of the “Maestro FuzzTone” on the Rolling Stone’s 1965 hit, “Satisfaction.”
Towards the late 1960’s and early 1970’s, players such as Jimmy Page and Jimi Hendrix began to create more extreme, heavy, sounds with their cranked up stacks. This advancement was furthered by players such as Eddie Van Halen whose specially modified amplifiers allowed him to create extreme distortion effects, and defining what would become the standard “heavy metal” guitar sound.
Terminology Typically Used to Describe Clipping Effects
Germanium: A germanium fuzz uses germanium transistors or diodes to create a warmer, splattier fuzz sound. Examples include the Arbiter Fuzz Face and Vox Tonebender.
Silicon: A silicon fuzz uses silicon transistors to create a harsh, more metallic fuzz sound. Later fuzz faces used silicon transistors.
MOSFET: A pedal that uses MOSFET transistors to achieve, organic, amp like overdrive and feel. The Fulltone Fulldrive is a common example.
EL84: A type of poweramp tube commonly used and associated with vox AC30’s.
EL34: A type of poweramp tube commonly associated with the sought after crunch of classic Marshall Amplifiers.