Distortion (music)

Distortion furnishings actualize "warm", "dirty" and "fuzzy" sounds by burden the peaks of a agreeable instrument's complete beachcomber and abacus overtones. The three arch types of baloney furnishings are overdrive, baloney and fuzz. Baloney furnishings are sometimes alleged “gain” effects, as adulterated guitar sounds were aboriginal accomplished by over-driving tube amplifiers.123 Baloney has continued been basic to the complete of bedrock and cycle music, and is important to added music genres such as electric dejection and jazz.45

The agreement “distortion”, “overdrive” and “fuzz” are generally acclimated interchangeably, but they accept attenuate differences in meaning. Overdrive furnishings are the mildest of the three, bearing "warm" overtones at quieter volumes and harsher baloney as accretion is increased. A "distortion" aftereffect produces about the aforementioned bulk of baloney at any volume, and its complete alterations are abundant added arresting and intense.67 A fuzzbox (or “fuzz box”) alters an audio arresting until it is about a aboveboard beachcomber and adds circuitous overtones by way of a abundance multiplier.8

Distortion can be produced by furnishings pedals and rackmounts, pre-amplifiers, ability amplifiers, speakers and added recently, agenda amplifier clay accessories and software.23

History

The aboriginal amplifiers congenital for electric guitar were almost low-fidelity, and would generally aftermath baloney if their aggregate (gain) was added above their architecture absolute or if they abiding accessory damage.9 One of the ancient recorded examples of baloney in bedrock music is the 1951 Ike Turner and the Kings of Rhythm song "Rocket 88", on which guitarist Willie Kizart acclimated an amplifier that had been hardly damaged in transport.10 In the aboriginal 1950s, beat bedrock guitarist Willie Johnson of Howlin' Wolf began advisedly accretion accretion above its advised levels to aftermath "warm" adulterated sounds.9 Chuck Berry's 1955 archetypal "Maybellene" appearance a guitar abandoned with balmy overtones created by his baby valve amplifier.11

By the mid 1950s bedrock guitarists began carefully "doctoring" amplifiers and speakers in adjustment to actualize even harsher distortion.12 In 1956 guitarist Paul Burlison of the Johnny Burnette Trio advisedly dislodged a exhaustion tube in his amplifier to almanac "The Train Kept A-Rollin” afterwards a analyst raved about the complete Burlison’s damaged amplifier produced during a reside performance.13 Guitarist Link Wray began carefully manipulating his amplifiers' exhaustion tubes to actualize a “noisy" and “dirty” complete for his solos afterwards a analogously adventitious discovery. Wray aswell poked holes in his apostle cones with pencils to added alter his tone. The resultant complete can be heard on his awful affecting 1958 instrumental, "Rumble".14

In 1961, the American active bedrock bandage The Ventures asked their acquaintance affair artist and electronics enthusiast Orville "Red" Rhodes for advice recreating the “fuzz” complete acquired by a adulterated preamplifier on Grady Martin’s guitar clue for the Marty Robbins song "Don't Worry".15 Rhodes offered The Ventures a fuzzbox he had made, which they acclimated to almanac "2000 Pound Bee" in 1962.16 The aboriginal purpose-designed bartering baloney ambit was the Maestro "Fuzz Tone" Model FZ-1, appear in 1962.17

In 1962 the American active bedrock bandage The Ventures recorded "2000 Pound Bee" application the aboriginal fuzzbox.

Distortion acquired boundless acceptance afterwards guitarist Dave Davies of The Kinks acclimated a razor brand to carve his apostle cones for their 1964 individual "You Really Got Me".18 In 1966, Jim Marshall of the British aggregation Marshall Amplification began modifying the cyberbanking chip of his amplifiers so as to accomplish a "brighter, louder" complete and fuller baloney capabilities.1920

In May 1965 Keith Richards acclimated a Gibson Maestro Fuzz-Tone to almanac "(I Can't Get No) Satisfaction".21 The song's success abundantly additional sales of the device, and all accessible banal awash out by the end of 1965.22 Aboriginal fuzzboxes cover the Mosrite FuzzRITE and Arbiter Group Fuzz Face acclimated by Jimi Hendrix,23 the Electro-Harmonix Big Muff Pi acclimated by Hendrix and Carlos Santana,24 and the Vox Accent Bender acclimated by Paul McCartney on "Think for Yourself" and added Beatles recordings.25

In the backward 1960s and aboriginal 1970s harder bedrock bands such as Deep Purple, Led Zeppelin and Black Sabbath artificial what would eventually become the abundant metal complete through a accumulated use of top volumes and abundant distortion.26

Theory and circuits

The chat baloney in fact refers to any modification or accession to the beachcomber anatomy of a arresting by any affectionate of equipment.27 In the ambience of music addition baloney is equated with clipping.28

Clipping is a non-linear action that produces frequencies not originally present in the audio signal. These frequencies can either be "harmonic", acceptation they are accomplished amount multiples of the signal's aboriginal frequencies, or "inharmonic", acceptation anomalous odd-order overtones.2930 Harmonic baloney produces harmonically accompanying overtones while intermodulation baloney produces cacophonic overtones.31

"Soft clipping" gradually flattens the peaks of a arresting and de-emphasizes college odd harmonics. "Hard clipping" flattens peaks abruptly, consistent in harsh-sounding, top amplitude odd harmonics.32

Distortion circuits alter a arresting afore it alcove the capital amplifier. Overdrive circuits do not actualize baloney themselves but rather addition signals to levels that could cause baloney to action at the capital amplifier's foreground end stage.33

edit Valve overdrive

Triode valve

Vacuum tube or “valve” baloney is accomplished by “overdriving” the valves in an amplifier.34Valve amplifiers--particularly those application triodes--tend to aftermath agee bendable abridgement that creates "warm"-sounding even-order harmonics.3235

A basal triode valve contains a cathode, a bowl and a grid. If a absolute voltage is activated to the plate, a accepted of abnormally answerable electrons flows to it from the acrimonious cathode through the grid. This increases the voltage of the audio signal, amplifying its volume. The filigree regulates the admeasurement to which bowl voltage is increased. A baby abrogating voltage activated to the filigree causes a ample abatement in bowl voltage.36

Valve addition is added or beneath linear--meaning the ambit (amplitude, frequency, phase) of the amplified arresting are proportional to the ascribe signal--so continued as the voltage of the ascribe arresting does not beat the valve's "linear arena of operation". The beeline arena avalanche amid 1. the assimilation region: the voltages at which bowl accepted stops responding to absolute increases in filigree voltage and 2. the blow region: the voltages at which the allegation of the filigree is too abrogating for electrons to breeze to the plate. If a valve is biased aural the beeline arena and the ascribe signal's voltage exceeds this region, overdrive and non-linear abridgement will occur.3734

Multiple stages of valve gain/clipping can be "cascaded" to aftermath a thicker and added circuitous baloney sound. In some avant-garde valve effects, the "dirty" or "gritty" accent is in fact accomplished not by top voltage, but by active the ambit at voltages that are too low for the ambit components, consistent in greater non-linearity and distortion. These designs are referred to as "starved plate" configurations, and aftereffect in an "amp death" sound.citation needed

edit Solid-state distortion

Solid-state amplifiers absorb detached transistors and/or op amps and are decumbent to aftermath harder abridgement and balanced baloney if overdriven. This adds added high-amplitude odd harmonics, creating a "dirty" or "gritty" tone.32 Electronically, this is usually accomplished by either amplifying the arresting to a point area it have to be abrupt to the accumulation rails, or by abridgement the arresting beyond diodes.citation needed Many solid-state baloney accessories attack to challenge the complete of overdriven exhaustion valves application added solid-state circuitry. Some amplifiers (notably the Marshall JCM 900) advance amalgam designs that apply both valve and solid-state components.citation needed

Guitar distortion approaches

Guitar baloney can be produced by abounding apparatus of the guitar's arresting path, including furnishings pedals, the pre-amplifier, ability amplifier, and speakers. Abounding players use a aggregate of these to access their "signature" tone.

edit Overdrive/distortion pedals

About this complete Demo of a Big Muff (help·info)

The Ibanez TS9 Tube Screamer, a accepted overdrive pedal

Because they are generally advised to accomplish with low voltages (such as 9 volt batteries), overdrive and baloney pedals about use transistors to accomplish distortion. Classic examples cover the Ibanez Tube Screamer and the Electro-Harmonix Big Muff.

To abate exceptionable dissonance, individual addendum and simple ability chords (root, fifth, and octave) are generally acclimated if application fuzzboxes, rather than triads (root, third, and fifth) or four-note chords (root, third, fifth, and seventh).

edit Pre-amplifier distortion

The pre-amplifier area of a guitar amplifier serves to amplify a anemic apparatus arresting to a akin that can drive the ability amplifier. It generally aswell contains chip to appearance the accent of the instrument, including equalization and accretion controls. Generally assorted bottomward gain/clipping stages are active to accomplish distortion. Because the aboriginal basic in a valve amplifier is a valve accretion stage, the achievement akin of the above-mentioned elements of the arresting alternation has a able access on the baloney created by that stage. The achievement akin of the guitar's pickups, the ambience of the guitar's aggregate knob, how harder the strings are plucked, and the use of volume-boosting furnishings pedals can drive this date harder and actualize added distortion.

During the 1980s and 1990s, abounding amps featured a "master volume" control, an adjustable attenuator amid the preamp area and the ability amp. If the preamp is set up to accomplish top baloney levels the adept aggregate can be acclimated to alter a lot of of the consistent arresting abroad from the ability valves, befitting the achievement aggregate at acquiescent levels.

edit Ability amplifier distortion

A brace of 6L6GC ability valves, generally acclimated in American-made amplifiers

Power valves can be overdriven in the aforementioned way that pre-amplifier valves can, but because these valves are advised to achievement added power, the baloney and appearance they add to the guitar's accent is unique. During the 1960s to aboriginal 1970s, baloney was primarily created by overdriving the ability valves. Because they accept become acclimatized to this sound, abounding guitar players favour this blazon of distortion, and appropriately set their amps to best levels in adjustment to drive the ability area hard. Abounding valve-based amplifiers in accepted use accept a push-pull achievement agreement in their ability section, with akin pairs of tubes active the achievement transformer. Ability amplifier baloney is absolutely symmetric, breeding predominantly odd-order harmonics.

Because active the ability valves this harder aswell agency best volume, which can be difficult to administer in a baby recording or call space, abounding solutions accept emerged that in some way alter some of this ability valve achievement from the speakers, acquiesce the amateur to accomplish ability valve baloney after boundless volume. These cover congenital or abstracted ability attenuators and power-supply-based ability attenuation.specify Lower-power valve amps (such as a quarter-watt or less), apostle abreast cabinets, and low-efficiency guitar speakers are aswell acclimated to acclimatized the volume.

Power-valve baloney can aswell be produced in a committed rackmount valve ability amp. A modular rackmount bureaucracy generally involves a rackmount preamp, a rackmount valve ability amp, and a rackmount copy amount to abate the achievement to adapted aggregate levels. Some furnishings pedals internally aftermath power-valve distortion, including an alternative copy amount for use as a power-valve baloney pedal. Such furnishings units can use a preamp valve such as the 12AX7 in a power-valve ambit agreement (as in the Stephenson's Date Hog), or use a accepted ability valve, such as the EL84 (as in the H&K Crunch Adept bunched tabletop unit). However, because these are usually placed afore the pre-amplifier in the arresting chain, they accord to the all-embracing accent in a altered way.

A Absolute Inject arresting can abduction the power-tube baloney complete after the absolute blush of a guitar apostle and microphone. This DI arresting can be attenuated with a miked guitar speaker, with the DI accouterment a added present, immediate, ablaze sound, and the miked guitar apostle accouterment a colored, remote, darker sound. The DI arresting can be acquired from a DI jack on the guitar amp, or from the Line Out jack of a ability attenuator.

Output transformer distortion

The achievement agent sits amid the ability valves and the speaker, confined to bout impedance. When a transformer's ferromagnetic amount becomes electromagnetically saturated, it will blow symmetrically. This adds added odd-order baloney to the arresting delivered to the speakers.

edit Ability accumulation "sag"

Early valve amplifiers acclimated able ability supplies. This was due to the top amount associated with high-quality high-voltage ability supplies. The archetypal anode accumulation was artlessly a rectifier, an inductor and a capacitor. When the valve amplifier was operated at top volume, the ability accumulation voltage would dip, abbreviation ability achievement and causing arresting abrasion and compression. This dipping aftereffect is accepted as "sag", and is approved by some electric guitarists.38 Sag alone occurs in Class AB amplifiers. This is because, technically, sag after-effects from added accepted getting fatigued from the ability supply, causing a greater voltage bead over the rectifier valve. In a Class A amplifier, accepted draw is constant, so sag does not occur.

As this aftereffect is added arresting with college ascribe signals, the harder "attack" of a agenda will be aeroembolism added heavily than the lower-voltage "decay", authoritative the closing assume louder and thereby convalescent sustain. Additionally, because the akin of compression is afflicted by ascribe volume, the amateur can ascendancy it via their arena intensity: arena harder after-effects in added compression or "sag". In contrast, avant-garde amplifiers generally use high-quality, adapted ability supplies.

edit Apostle distortion

Guitar loudspeakers are advised abnormally from top allegiance stereo speakers or PA arrangement speakers. While hi-fi and PA speakers are advised to carbon the complete with as little baloney as possible, guitar speakers are usually advised so that they will appearance or colour the accent of the guitar, either by acceptable some frequencies or attenuating exceptionable frequencies.citation needed

When the ability delivered to a guitar apostle approaches its best rated power, the speaker's achievement degrades, causing the apostle to "break up", abacus added baloney and colouration to the signal. Some speakers are advised to accept lots of apple-pie headroom, while others are advised to breach up aboriginal to bear dust and growl.

Amp modeling for distortion emulation

Guitar amp clay accessories and software can carbon assorted guitar-specific baloney qualities that are associated with a ambit of accepted "stomp box" pedals and amplifiers. Amp clay accessories about use agenda arresting processing to charm the complete of active into alternation pedals and overdriven valve amplifiers. The a lot of adult accessories acquiesce the user to adapt the apish after-effects of application altered preamp, power-tube, apostle distortion, apostle cabinet, and microphone adjustment combinations. For example, a guitarist application a baby amp clay pedal could simulate the complete of active their electric guitar into a abundant best valve amplifier and a assemblage of 8 X 10" apostle

Voicing with equalization

Guitar baloney is acquired and shaped at assorted credibility in the arresting processing chain, including assorted stages of preamp distortion, ability valve distortion, achievement and ability agent distortion, and guitar apostle distortion. Much of the baloney appearance or delivery is controlled by the abundance acknowledgment afore and afterwards anniversary baloney stage. This annex of baloney delivery on abundance acknowledgment can be heard in the aftereffect that a wah pedal has on the consecutive baloney stage, or by application accent controls congenital in to the guitar, the preamp or an EQ pedal to favor the bass or acute apparatus of the guitar auto arresting above-mentioned to the aboriginal baloney stage. Some guitarists abode an blaster pedal afterwards the baloney effect, to accent or de-emphasize altered frequencies in the adulterated signal.

Increasing the bass and acute while abbreviation or eliminating the centre midrange (750 Hz) after-effects in what is bargain accepted as a "scooped" complete (since the midrange frequencies are "scooped" out). Conversely, abbreviating the bass while accretion the midrange and acute creates a punchy, harsher sound.