Guitar amplifier

A guitar amplifier (or amp) is an electronic device or system that strengthens the weak electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which are typically housed in a wooden cabinet. In confusion over nomenclature, Fender labeled early amplifier tremolo as "vibrato" and called the vibrato arm of the Stratocaster guitar a "tremolo bar" (see vibrato unit, electric guitar, and tremolo).

The pickup generally uses electromagnetic induction to create this signal, which being relatively weak is fed into a guitar amplifier before being sent to the speaker(s), which converts it into audible sound.

Guitar amplifiers can also modify the instrument's tone by emphasizing or de-emphasizing certain frequencies, using equalizer controls, which function the same way as the bass and treble knobs on a home hi-fi stereo, and by adding electronic effects; distortion (also called "overdrive") and reverb are commonly available as built-in features.

Guitarists playing electric blues originally obtained an overdriven sound by turning up their vacuum tube-powered guitar amplifiers to high volumes, which caused the signal to distort.

The input of modern guitar amplifiers is a 1/4" jack, which is fed a signal from an electro-magnetic pickup (from an electric guitar) or a piezoelectric pickup (usually from an acoustic guitar) using a patch cord, or a wireless transmitter. For electric guitar players, their choice of guitar amp and the settings they use on the amplifier are a key part of their signature tone or sound. Some guitar players are longtime users of a specific amp brand or model. Guitarists may also use external effects pedals to alter the sound of their tone before the signal reaches the amplifier.

It also finds everyday uses such as acting as the ignition source for cigarette lighters, push-start propane barbecues, used as the time reference source in quartz watches, as well as in amplification pickups for some guitars and triggers in most modern electronic drums.

When engineers developed the first AC mains-powered amplifiers, they were soon used to make musical instruments louder.

In certain applications, like guitar amplifiers, different waveforms are used, such as triangular or square waves.

Some later amplifier models included an onboard spring reverb effect, one of the first being the Ampeg Reverberocket amp. As such, in the 1950s, when Ampeg introduced bass amplifier and speaker systems, bass guitarists began to use them.

Although the company specializes in the production of bass amplifiers, it has previously manufactured guitar amplifiers, pickups and several instruments including, double basses, bass guitars, and electric guitars.

The first electric instrument amplifiers were not intended for electric guitars, but were portable PA systems.

Instrument amplifiers are available for specific instruments, including the electric guitar, electric bass, electric/electronic keyboards, and acoustic instruments such as the mandolin and banjo.

In confusion over nomenclature, Fender labeled early amplifier tremolo as "vibrato" and called the vibrato arm of the Stratocaster guitar a "tremolo bar" (see vibrato unit, electric guitar, and tremolo).

Vibrato units may be individual stomp boxes or built into multi-effects units, but are traditionally built into guitar amplifiers.

In confusion over nomenclature, Fender labeled early amplifier tremolo as "vibrato" and called the vibrato arm of the Stratocaster guitar a "tremolo bar" (see vibrato unit, electric guitar, and tremolo). Some models also provided effects such as an electronic tremolo unit.

Electronic tremolo effects were available on many early guitar amplifiers.

In the early 1960s, surf rock guitarist Dick Dale worked closely with Fender to produce custom made amplifiers, including the first 100-watt guitar amplifier.

Dale worked closely with the manufacturer Fender to produce custom-made amplifiers including the first-ever 100-watt guitar amplifier.

The combo amp had "two 8″ Lansing speakers and a five-tube chassis. Dobro made a two speaker combo amp that was on the market over 12 years before Fender launched its two-speaker "Dual Professional/Super" combo amp. In 1933, Audio-Vox was founded by Paul Tutmarc, the inventor of the first electric bass (Tutmarc's instrument did not achieve market success until Leo Fender's launched the Precision Bass). In 1933, Vega sold a pickup and amplifier set for musicians to use with existing guitars.

The 12AX7 is a dual "high mu" (high voltage gain ) triode in a miniature enclosure, and became widely used in audio signal amplifiers, instruments, and guitar amplifiers.

As such, in the 1950s, when Ampeg introduced bass amplifier and speaker systems, bass guitarists began to use them.

While bass amps share many features with the guitar amplifiers used for electric guitar, they are distinct from other types of amplification systems, due to the particular challenges associated with low-frequency sound reproduction.

Amplifiers may use vacuum tubes (called valves in Britain), solid-state (transistor) devices, or both.

Valve amplifiers can be used for applications such as guitar amplifiers, satellite transponders such as DirecTV and GPS, audiophile stereo amplifiers, military applications (such as radar) and very high power radio and UHF television transmitters.

Guitar amplifiers can also modify the instrument's tone by emphasizing or de-emphasizing certain frequencies, using equalizer controls, which function the same way as the bass and treble knobs on a home hi-fi stereo, and by adding electronic effects; distortion (also called "overdrive") and reverb are commonly available as built-in features.

Stereos and basic guitar amplifiers typically have adjustable equalizers which boost or cut bass or treble frequencies.

In confusion over nomenclature, Fender labeled early amplifier tremolo as "vibrato" and called the vibrato arm of the Stratocaster guitar a "tremolo bar" (see vibrato unit, electric guitar, and tremolo).

Dick Dale was a prominent Stratocaster player who also collaborated with Leo Fender in developing the Fender Showman amplifier.

Alternatively, a tube preamplifier can feed a solid-state output stage, as in models from Kustom, Hartke, SWR and Vox.

Kustom Amplification or Kustom Electronics is a manufacturer of guitar and bass amplifiers and PA equipment and accessories.

These included Goree Carter, Joe Hill Louis, Elmore James, Ike Turner, Willie Johnson, Pat Hare, Guitar Slim, Chuck Berry, Johnny Burnette, and Link Wray.

The music historian Robert Palmer regards "Rock Awhile" to be a more appropriate candidate for the "first rock and roll record" title, because it was recorded two years earlier, and because of Carter's guitar work bearing a striking resemblance to Chuck Berry's later guitar work, while making use of an over-driven amplifier, along with the backing of boogie-based rhythms, and the appropriate title and lyrical subject matter.

Besides instrument inputs and speaker outputs (typically via 1/4" jacks), an amp may have other inputs and outputs. These can include an auxiliary input jack (sometimes with its own level control, for a drum machine), "send" and "return" jacks to create an effects loop, a “line out” jack and an extension speaker jack. Practice amps sometimes have a 1/4" headphone jack, or stereo RCA or mini jacks for connecting a CD player, portable media player or other sound source.

In the early 1960s, a home organ manufacturer, Gulbransen (later acquired by Fender) cooperated with an automatic musical equipment manufacturer Seeburg Corporation, and released early compact rhythm machines Rhythm Prince (PRP), although, at that time, these size were still as large as small guitar amp head, due to the use of bulky electro-mechanical pattern generators.

A guitar amplifier (or amp) is an electronic device or system that strengthens the weak electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which are typically housed in a wooden cabinet.

Electric musical instruments invented in the 20th century, such as the electric guitar, electric bass and synthesizer, among others, are amplified using instrument amplifiers and speaker cabinets (e.g., guitar amplifier speaker cabinets).

The two common guitar amplifier configurations are: a combination ("combo") amplifier that includes an amplifier and one or more speakers in a single cabinet, and a standalone amplifier (often called a "head" or "amp head"), which passes the amplified signal via a speaker cable to one or more external speaker cabinets.

A guitar speaker is a loudspeaker – specifically the driver (transducer) part – designed for use in a combination guitar amplifier (in which a loudspeaker and an amplifier are installed in a wooden cabinet) of an electric guitar, or for use in a guitar speaker cabinet.

In 1934, Rickenbacker launched a similar combo amp that added metal corner protectors to keep the corners in good condition during transportation.

Using a modeling amp or a multi effects pedal used with line level output, a guitarist can plug in the guitar into a flat response mic input or into a keyboard amplifier.

Keyboard amplifiers are distinct from other types of amplification systems such as guitar amplifiers due to the particular challenges associated with making keyboards sound louder on stage; namely, to provide solid low-frequency sound reproduction for the deep basslines which keyboards can play and crisp high-frequency sound for the high-register notes.

A guitar amplifier may be a standalone wood or metal cabinet that contains only the power amplifier (and preamplifier) circuits, requiring the use of a separate speaker cabinet–or it may be a "combo" amplifier, which contains both the amplifier and one or more speakers in a wooden cabinet.

Audio power amplifiers are found in all manner of sound systems including sound reinforcement, public address and home audio systems and musical instrument amplifiers like guitar amplifiers.

These are known as modeling amplifiers, and can be programmed with simulated characteristic tones of different existing amplifier models (and speaker cabinets—even microphone type or placement), or dialed in to the user's taste.

Amplifier modeling (also known as amp modeling or amp emulation) is the process of emulating a physical amplifier such as a guitar amplifier.

These included Goree Carter, Joe Hill Louis, Elmore James, Ike Turner, Willie Johnson, Pat Hare, Guitar Slim, Chuck Berry, Johnny Burnette, and Link Wray.

According to Allmusic, "what is now easily attainable by 16-year-old kids on modern-day effects pedals just by stomping on a switch, Hare was accomplishing with his fingers and turning the volume knob on his Sears & Roebuck cereal-box-sized amp all the way to the right until the speaker was screaming."

Alternatively, a tube preamplifier can feed a solid-state output stage, as in models from Kustom, Hartke, SWR and Vox.

SWR Sound Corporation is a specialist manufacturer of bass guitar amplifiers, preamps, speaker cabinets, and acoustic guitar amplifiers.