Electric guitar

posted on 19 Jan 2009 22:21 by bbaaaall

An electric guitar is a type of guitar that uses pickups to convert the vibration of its steel-cored strings (sometimes nickel) into an electrical current, which is made louder with an instrument amplifier and a speaker. The signal that comes from the guitar is sometimes electronically altered with guitar effects such as reverb or distortion. While most electric guitars have six strings, seven-string instruments are used by some jazz guitarists and metal guitarists (especially in nu metal), and 12-string electric guitars (with six pairs of strings, four of which are tuned in octaves) are used in genres such as jangle pop and rock.

The electric guitar was first used by jazz guitarists, who used amplified hollow-bodied instruments to get a louder sound in Swing-era big bands. The earliest electric guitars were hollow bodied acoustic instruments with tungsten steel pickups made by the "Rickenbacker" company in 1931. While one of the first solid-body guitars was invented by Les Paul, the first commercially successful solid-body electric guitar was the Fender Esquire (1950). The electric guitar was a key instrument in the development of many musical styles that emerged since the late 1940s, such as Chicago blues, early rock and roll and rockabilly, and 1960s blues rock. It is also used in a range of other genres, including country music, Ambient (or New Age), and in some contemporary classical music.

History

The need for an amplified guitar became apparent during the big band era, as jazz orchestras of the 1930s and 1940s increased in size, with larger brass sections. Initially, electric guitars used in jazz consisted primarily of hollow archtop acoustic guitar bodies to which electromagnetic transducers had been attached.

Early years                    
                                
Sketch of Rickenbacker "frying pan" lap steel from 1934 patent application.

 

Electric guitars were originally designed by an assortment of luthiers, guitar makers, electronics enthusiasts, and instrument manufacturers. Guitar innovator Les Paul experimented with microphones attached to guitars. Some of the earliest electric guitars adapted hollow bodied acoustic instruments and used tungsten pickups. This type of guitar was manufactured beginning in 1932 by Electro String Instrument Corporation in Los Santos under the direction of Adolph Rickenbacher and George Beauchamp. Their first design was built by Harry Watson, a craftsman who worked for the Electro String Company. This new guitar which the company called "Rickenbacker" would be the first of its kind.

The earliest documented performance with an electrically amplified guitar was in 1932, by guitarist and bandleader Gage Brewer. The Wichita, Kansas-based musician had obtained two guitars, an Electric Hawaiian A-25 (Fry-pan, lap-steel) and a standard Electric Spanish from his friend George Beauchamp of Los Angeles, California. Brewer publicized his new instruments in an article in the Wichita Beacon, October 2, 1932 and through performances that month.

The first recordings using the electric guitar were made by Hawaiian Style players such as Andy Iona as early as 1933. Bob Dunn of Milton Brown's Musical Brownies introduced the electric Hawaiian guitar to Western Swing with his January 1935 Decca recordings, departing almost entirely from Hawaiian musical influence and heading towards Jazz and Blues. Alvino Rey was an artist who took this instrument to a wide audience in a large orchestral setting and later developed the pedal steel guitar for Gibson. An early proponent of the electric Spanish guitar was jazz guitarist George Barnes who used the instrument in two songs recorded in Chicago on March 1st, 1938, Sweetheart Land and It's a Low-Down Dirty Shame. Some historians incorrectly attribute the first recording to Eddie Durham, but his recording with the Kansas City Five was not until 15 days later. Durham introduced the instrument to a young Charlie Christian, who made the instrument famous in his brief life and is generally known as the first electric guitarist and a major influence on jazz guitarists for decades thereafter.

The first recording of an electric Spanish guitar, west of the Mississippi was in Dallas, in September 1935, during a session with Roy Newman and His Boys, an early Western swing dance band. Their guitarist, Jim Boyd, used his electrically amplified guitar during the recording of three songs, "Hot Dog Stomp" (DAL 178-Vo 03371), "Shine On, Harvest Moon" (DAL 180-Vo 03272), and "Corrine, Corrina" (DAL 181-Vo/OK 03117).An even earlier Chicago recording of an electrically amplified guitar—albeit an amplified lap steel guitar—was during a series of session by Milton Brown and His Brownies (another early Western swing band) that took place January 27-28, 1935, wherein Bob Dunn played his amplified Hawaiian guitar.

Early proponents of the electric guitar on record include: Jack Miller (Orville Knapp Orch.), Alvino Rey (Phil Spitalney Orch.), Les Paul (Fred Warring Orch.), Danny Stewart (Andy Iona Orchestra), George Barnes (under many alias), Floyd Smith, Bill Broonzy, T-Bone Walker, George Van Eps, Charlie Christian (Benny Goodman Orch.) Tampa Red, Memphis Minnie, and Arthur Cruddup.

Early electric guitar manufacturers include: Rickenbacker (first called Ro-Pat-In) in 1932, Dobro in 1933, National, AudioVox and Volu-tone in 1934,Vega, Epiphone (Electrophone and Electar), and Gibson in 1935 and many others by 1936.

The version of the instrument that is best known today is the solid body electric guitar, a guitar made of solid wood, without resonating airspaces within it. Rickenbacher, later spelled Rickenbacker, did, however, offer a cast aluminum electric steel guitar, nicknamed The Frying Pan or The Pancake Guitar, developed in 1931 with production beginning in the summer of 1932. This guitar sounds quite modern and aggressive as tested by vintage guitar researcher John Teagle. The company Audiovox built and may have offered an electric solid-body as early as the mid-1930s.

Another early solid body electric guitar was designed and built by musician and inventor Les Paul in the early 1940s, working after hours in the Epiphone Guitar factory. His log guitar (so called because it consisted of a simple 4x4 wood post with a neck attached to it and homemade pickups and hardware, with two detachable Swedish hollow body halves attached to the sides for appearance only) was patented and is often considered to be the first of its kind, although it shares nothing in design or hardware with the solid body "Les Paul" model sold by Gibson. In 1945, Richard D. Bourgerie made an electric guitar pickup and amplifier for professional guitar player George Barnes. Bourgerie worked through World War II at Howard Radio Company making electronic equipment for the American military. Mr. Barnes showed the result to Les Paul, who then arranged for Mr. Bourgerie to have one made for him.

Fender         

                 

                               
    Sketch of Fender lap steel guitar from 1944 patent application.

In 1946, radio repairman and instrument amplifier maker Clarence Leonidas Fender—better known as Leo Fender—through his eponymous company, designed the first commercially successful solid-body electric guitar with a single magnetic pickup, which was initially named the "Esquire". This was a departure from the typically hollow-bodied Jazz-oriented instruments of the time and immediately found favor with Country-Western artists in California. The two-pickup version of the Esquire was called the "Broadcaster". However, Gretsch had a drumset marketed with a similar name (Broadkaster), so Fender changed the name to "Telecaster".

Features of the Telecaster included: an ash body; a maple 25½" scale, 21-fret or 22-fret neck attached to the body with four-bolts reinforced by a steel neckplate; two single-coil, 6-pole pickups (bridge and neck positions) with tone and volume knobs, pickup selector switch; and an output jack mounted on the side of the body. A black bakelite pickguard concealed body routings for pickups and wiring. The bolt-on neck was consistent with Leo Fender's belief that the instrument design should be modular to allow cost-effective and consistent manufacture and assembly, as well as simple repair or replacement. Due to the earlier mentioned trademark issue, some of the first production Telecasters were delivered with headstock decals with the Fender logo but no model identification. These are today very much sought after, and commonly referred to by collectors as "Nocasters".

In 1954, Fender introduced the Fender Stratocaster, or "Strat." The Stratocaster was seen as a deluxe model and offered various product improvements and innovations over the Telecaster. These innovations included a well dried ash or alder double-cutaway body design for bridge assembly with an integrated spring vibrato mechanism (called a synchronized tremolo by Fender, thus beginning a confusion of the terms that still continues), three single-coil pickups, and body comfort contours. Leo Fender is also credited with developing the first commercially successful electric bass guitar called the Fender Precision Bass, introduced in 1951.

Vox

In 1962 Vox introduced the pentagonal Phantom guitar, originally made in England but soon after made by Alter EKO of Italy. It was followed a year later by the teardrop-shaped Mark VI, the prototype of which was used by Brian Jones of The Rolling Stones, and later Johnny Thunders of the New York Dolls. Vox guitars also experimented with onboard effects and electronics. In the mid 1960s, as the sound of electric 12-string guitars became popular, Vox introduced the Phantom XII and Mark XII electric 12-string guitars as well as the Tempest XII which employed a more conventional Fender style body and thus is often overlooked as a Vox classic from the Sixties. The few that were manufactured also came from Italy. Vox also produced other traditional styles of 6- and 12-string electric guitars in both England and Italy, The 12-string electric guitars had a much larger neck and body and averaged at the weight of 26.4 pounds(11.9kg), they were also played on tables such as a piano or other sit down instrument.

Construction                    

While guitar construction has many variations, in terms of the materials used for the body, the shape of the body, and the configuration of the neck, bridge, and pickups, there are features which are found in almost every guitar. The photo below shows the different parts of an electric guitar. The headstock(1) contains the metal machine heads, which are used for tuning ; the nut(2), a thin fret-like strip of metal or plastic which the strings pass over as they first go onto the fingerboard; the machine heads (3), which are worm gears which the player turns to change the string tension and thus adjust the tuning; the frets(4), which are thin metal strips which stop the string at the correct pitch when a string is pressed down against the fingerboard; the truss rod(5) , a metal cylinder used for adjusting the tension on the neck (not found on all instruments); decorative inlay (6), a feature not found on lower-cost instruments.

The neck and the fretboard (7) extend from the body; at the neck joint (8), the neck is either glued or bolted to the body; the body (9)- in this instrument, it is made of wood which is painted and lacquered, but some guitar bodies are also made of polycarbonate or other materials ; pickups (10), which are usually magnetic pickups, but which may also be piezoelectric transducer pickups; the control knobs (11) for the volume and tone potentiometers ; a fixed bridge(12)-on some guitars, a spring-loaded hinged bridge called a "tremolo system" is used instead, which allows players to "bend" notes or chords down in pitch or perform a vibrato embellishment; and a plastic pickguard(13), a feature not found on all guitars, which is used to protect the body from scratches.

The wood that the body (9) is made of largely determines the sonic qualities of the guitar. Typical woods include alder(brighter, but well rounded), swamp ash(similar to alder, but with more pronounced highs and lows), mahogany(dark, bassy, warm), poplar(similar to mahogany) and basswood(very neutral). Maple, a very bright tonewood, is also a popular body wood, but is very heavy. For this reason it is often placed as a 'cap' on a guitar made of primarily of another wood. Cheaper guitars are often made of cheap woods, such as plywood or agathis, and sound sterile and lifeless.

 Pickups

Compared with an acoustic guitar, which has a hollow body, electric guitars make comparatively little audible sound simply by having their strings plucked, and so electric guitars are normally plugged into a guitar amplifier, which makes the sound louder. When an electric guitar is strummed, the movement of the strings generates (i.e., "induces") a very small electrical current in the magnetic pickups, which are magnets wrapped with coils of very fine wire. That current is then sent through a cable to a guitar amplifier. The current induced is proportional to such factors as the density of the string or the amount of movement over these pickups. That vibration is, in turn, affected by several factors, such as the composition and shape of the body.

                                  

A close-up of the pickups on a Fender Squier "Stagemaster" guitar; on the left is a "humbucker" pickup and on the right are two single-coil pickups.

Some hybrid electric-acoustic guitars are equipped with additional microphones or piezoelectric pickups (transducers) that sense mechanical vibration from the body. Because in some cases it is desirable to isolate the pickups from the vibrations of the strings, a guitar's magnetic pickups will sometimes be embedded or "potted" in epoxy or wax to prevent the pickup from having a microphonic effect.

Because of their natural inductive qualities, all magnetic pickups tend to pick up ambient and usually unwanted electromagnetic noises. The resulting noise, the so-called "hum", is particularly strong with single-coil pickups, and aggravated by the fact that very few guitars are correctly shielded against electromagnetic interference. The most frequent cause is the strong 50 or 60 Hz component that is inherent in the frequency generation of current within the local power transmission system. As nearly all amplifiers and audio equipment associated with electrical guitars rely on this power, there is in theory little chance of completely eliminating the introduction of unwanted hum.

Double-coil or "humbucker" pickups were invented as a way to reduce or counter the unwanted ambient hum sounds. Humbuckers have two coils of opposite magnetic and electric polarity. This means that electromagnetic noise hitting both coils should cancel itself out. The two coils are wired in phase, so the signal picked up by each coil is added together. This creates the richer, "fatter" tone associated with humbucking pickups. Optical pickups  are a type of pickup which sense string and body vibrations using infrared LED light.

Sound and effects

While an acoustic guitar's sound is largely dependent on the vibration of the guitar's body and the air within it, the sound of an electric guitar is largely dependent on a magnetically induced electrical signal, generated by the vibration of metal strings near sensitive pickups. The signal is then "shaped" on its path to the amplifier by using a range of effect devices or circuits that modify the tone and characteristics of the signal. The most basic sound-shaping circuitry are the volume control (potentiometer), tone control (which "rolls off" the treble frequencies), and the pick-up selectors which are found on most electric guitars, and the gain and tone (usually consisting of at least bass and treble) controls on the guitar amplifier.

In the 1960s, some guitarists began exploring a wider range of tonal effects by distorting the sound of the instrument. To do this, they increased the gain, or volume, of the preamplifier, which produced a "fuzzy" sound. This effect is called "clipping" by sound engineers, because when viewed with an oscilloscope, the wave forms of a distorted signal appear to have had their peaks "clipped" off. This was not actually a new development in the instrument, but rather a shift of aesthetics. This sound was not generally recognized previously as desirable. In the 1960s, the tonal palette of the electric guitar was further modified by introducing an effects box in its signal path. Traditionally built in a small metal chassis with an on/off foot switch, such "stomp boxes" have become an important part of the electric guitar tone in many genres. Typical effects include stereo chorus, fuzz, wah-wah and flanging, compression/sustain, delay, reverb, and phase shift. Not all special effects are electronic; in 1967, guitarist Jimmy Page of The Yardbirds and Led Zeppelin created unusual, psychedelic sound effects by playing the electric guitar with a violin bow and smacking the strings with the bow.

                                

                               

A Boss "stomp-box"-style distortion pedal in use.

In the 1970s, as effects pedals proliferated, their sounds were combined with power-tube distortion at lower, more controlled volumes by using power attenuators such as Tom Scholz' Power Soak as well as re-amplified dummy loads such as Eddie Van Halen's use of a variac, power resistor, post-power-tube effects, and a final solid-state amp driving the guitar speakers. A variac is one approach to power-supply based power attenuation, to make the sound of power-tube distortion more practically available.

By the 1980s and 1990s, digital and software effects became capable of replicating the analog effects used in the past. These new digital effects attempted to model the sound produced by analog effects and tube amps, to varying degrees of quality. There are many free guitar effects computer programs for PCs that can be downloaded from the Internet. By the 2000s, PCs with specially designed sound cards could be used as digital guitar effects processors. Although digital and software effects offer many advantages, many guitarists still use analog effects.

In 2002, Gibson announced the first digital guitar, which performs analog-to-digital conversion internally. The resulting digital signal is delivered over a standard Ethernet cable, eliminating cable-induced line noise. The guitar also provides independent signal processing for each individual string. Also, in 2003 amp maker Line 6 released the Variax guitar. It differs in some fundamental ways from conventional solid-body electrics. For example it uses piezoelectric pickups instead of the conventional electromagnetic ones, and has an onboard computer capable of modifying the sound of the guitar to model the sound of many instruments.

 

edit @ 20 Jan 2009 21:38:46 by MyBalloon

edit @ 20 Jan 2009 21:40:50 by MyBalloon

edit @ 20 Jan 2009 22:53:55 by MyBalloon

edit @ 20 Jan 2009 23:04:22 by MyBalloon

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#1 By ReSiDeNt EvIl By NongZaSK128 on 2009-01-20 23:00