Why Did Tube Amps Become Popular Again in the 1990s

This article is virtually amplifiers for musical instruments. For amplifiers for exam and measurement, see instrumentation amplifier.

An instrument amplifier is an electronic device that converts the often barely audible or purely electronic point of a musical musical instrument into a larger electronic point to feed to a loudspeaker. An instrument amplifier is used with musical instruments such as an electrical guitar, an electric bass, electrical organ, synthesizers and drum machine to convert the bespeak from the pickup (with guitars and other cord instruments and some keyboards) or other sound source (e.g, a synthesizer's betoken) into an electronic indicate that has enough power, due to existence routed through a power amplifier, capable of driving 1 or more than loudspeaker that can be heard by the performers and audience.

Combination ("combo") amplifiers include a preamplifier, a ability amplifier, tone controls, and i or more than speakers in a cabinet, a housing or box usually made of hardwood, plywood or particleboard (or, less commonly, moulded plastic). Instrument amplifiers for some instruments are as well available without an internal speaker; these amplifiers, called heads, must plug into one or more external speaker cabinets. Instrument amplifiers also accept features that let the performer alter the signal's tone, such as irresolute the equalization (adjusting bass and treble tone) or adding electronic effects such as intentional distortion/overdrive, reverb or chorus effect.

A Fender "combo" amplifier. The combination amplifier is a preamplifier, ability amplifier and tone controls and one or more loudspeakers or drivers mounted in a portable wooden chiffonier. This amp's audio is being picked up with a microphone in a recording studio.

Instrument amplifiers are available for specific instruments, including the electric guitar, electric bass, electric/electronic keyboards, and audio-visual instruments such every bit the mandolin and banjo. Some amplifiers are designed for specific styles of music, such as the "traditional"-style "tweed" guitar amplifiers, such equally the Fender Bassman used past blues and country music musicians, and the Marshall amplifiers used by difficult rock and heavy metal bands.

Different home "hi-fi" amplifiers or public accost systems, which are designed to accurately reproduce the source sound signals with as piddling harmonic distortion as possible and without changing the tone or equalization (at least not unless the hello-fi owner adjusts information technology themselves with a graphic equalizer), musical instrument amplifiers are often designed to add boosted tonal coloration to the original indicate, emphasize (or de-emphasize) certain frequencies (virtually electric guitar amps scroll off the very high frequencies), and, in the case of guitar amplifiers designed for electric guitar or Hammond organ, offer the adequacy to intentionally add some degree of "overdrive" or distortion to the tone. The 2 exceptions are keyboard amplifiers designed for apply with digital pianos and synthesizers and "acoustic" instrument amplifiers for apply with acoustic guitar or fiddle in a folk music setting, which typically aim for a relatively flat frequency response (i.east., no added colouration of the sound) and picayune or no distortion of the bespeak.

Types [edit]

Guitar amplifiers [edit]

A guitar amplifier amplifies the electrical signal of an electrical guitar (or, less commonly, with acoustic amplifiers, an audio-visual guitar) so that information technology can drive a loudspeaker at sufficient volume for the performer and audience to hear. Most guitar amplifiers can too modify the instrument'south with controls that emphasize or de-emphasize certain frequencies and add electronic furnishings. String vibrations are sensed by a suitable microphone or pickup, depending on the type of guitar. For electrical guitars, strings are almost ever made of metal, and the pickup works by electro-magnetic consecration (these are called magnetic pickups; they are the near widely used type of pickup on electric guitars). Audio-visual guitars practice not usually take a congenital-in pickup or microphone, at least with entry-level and beginner instruments. Some acoustic guitars have a minor condenser microphone mounted inside the body, which designed to convert acoustic vibrations into an electrical signal, just usually they do so from direct contact with the strings (replacing the guitar's bridge) or with the guitar's body, rather than having a membrane like general-purpose microphones. Acoustic guitars may too employ a piezoelectric pickup, which converts the vibrations of the musical instrument into an electronic bespeak. More than rarely, a magnetic pickup may be mounted in the sound pigsty of an audio-visual guitar; while magnetic pickups do non accept the aforementioned acoustic tone that microphones and piezo pickups tin produce, magnetic pickups are more resistant to audio-visual feedback.

A minor Gibson "combo" amplifier.

Standard amps [edit]

Standard amplifiers, such as the Fender "tweed"-mode amps (east.1000., the Fender Bassman) and Gibson amps, are often used by traditional rock, dejection, and land musicians who wish to create a "vintage" 1950s-style sound. They are used past electric guitarists, pedal steel guitar players, and dejection harmonica ("harp") players. Combo amplifiers such as the Fender Super Reverb have powerful, loud tube amplifiers, four 10" speakers, and they frequently have built-in reverb and "vibrato" effects units. Smaller guitar amps are likewise available, which have fewer speakers (some have only one speaker) and lighter, less powerful amplifier units. Smaller guitar amps are easier to transport to gigs and audio recording sessions. Smaller amps are widely used in small-scale venue shows (nightclubs) and in recordings, considering players can obtain the tone they want without having to take an excessively loud volume. One of the challenge with the big, powerful 4x10 Fender Bassman-blazon amps is that to get the tone a player wants, they take to turn upwardly the amp to a loud book.

These amps are designed to produce a variety of sounds ranging from a clean, warm sound (when used in country and soft rock) to a growling, natural overdrive, when the volume is gear up nigh its maximum, (when used for dejection, rockabilly, psychobilly, and roots rock). These amplifiers usually take a sharp treble roll-off at five kHz to reduce the farthermost high frequencies, and a bass roll-off at threescore–100 Hz to reduce unwanted boominess. The nickname "tweed" refers to the lacquered biscuit-light brownish fabric covering used on these amplifiers.

The smallest "combo" amplifiers, which are mainly used for individual practise and warm-upward purposes, may have only a single 8" or 10" speaker. Some harmonica players use these small combo amplifiers for concert performances, though, because it is easier to create natural overdrive with these lower-powered amplifiers. Larger combo amplifiers, with one 12 inch speaker or two or four ten or 12 inch speakers are used for society performances and larger venues. For large concert venues such as stadiums, performers may also use an amplifier "head" with several carve up speaker cabinets (which normally comprise two or four 12" speakers).

Hard stone and heavy metal [edit]

Electric guitar amplifiers designed for heavy metal are used to add an aggressive "drive", intensity, and "edge" to the guitar audio with distortion furnishings, preamplification boost controls (sometimes with multiple stages of preamps), and tone filters. While many of the most expensive, high-end models use 1950s-style tube amplifiers (even in the 2000s), there are as well many models that use transistor amplifiers, or a mixture of the two technologies (i.e., a tube preamplifier with a transistor power amplifier). Amplifiers of this type, such as Marshall amplifiers, are used in a range of the louder, heavier genres of rock, including hard rock, heavy metal, and hardcore punk. This blazon of amplifier is available in a range of formats, ranging from pocket-sized, cocky contained combo amplifiers for rehearsal and warm-ups to heavy "heads" that are used with separate speaker cabinets—colloquially referred to every bit a "stack."

In the late 1960s and early on 1970s, public address systems at stone concerts were used mainly for the vocals. Every bit a result, to become a loud electric guitar sound, early heavy metal and stone-dejection bands often used "stacks" of 4x12" Marshall speaker cabinets on the phase. In 1969, Jimi Hendrix used four stacks to create a powerful lead audio, and in the early 1970s by the ring Blue Öyster Cult used an entire wall of Marshall Amplifiers to create a roaring wall of sound that projected massive volume and sonic power. In the 1980s, metallic bands such every bit Slayer and Yngwie Malmsteen also used "walls" of over 20 Marshall cabinets. However, by the 1980s and 1990s, most of the sound at live concerts was produced by the sound reinforcement system rather than the onstage guitar amplifiers, and so nigh of these cabinets were not continued to an amplifier. Instead, walls of speaker cabinets were used for aesthetic reasons.

Amplifiers for harder, heavier genres often use valve amplifiers (known every bit "tube amplifiers" in Due north America) besides. Valve amplifiers are perceived by musicians and fans to have a "warmer" tone than those of transistor amps, specially when overdriven (turned up to the level that the amplifier starts to clip or shear off the wave forms). Instead of abruptly clipping off the signal at cut-off and saturation levels, the signal is rounded off more smoothly. Vacuum tubes also showroom dissimilar harmonic effects than transistors. In contrast to the "tweed"-fashion amplifiers, which use speakers in an open up-backed cabinet, companies such equally Marshall tend to use 12" speakers in a closed-dorsum cabinet. These amplifiers usually allow users to switch between "make clean" and distorted tones (or a rhythm guitar-style "crisis" tone and a sustained "lead" tone) with a foot-operated switch.

A 2 x 10" bass speaker cabinet stacked on peak of a xv" cabinet, with separate bass amplifier "head" unit

Bass [edit]

Bass amplifiers are designed for bass guitars or more rarely, for upright bass. They differ from amplifiers for the electric guitar in several respects, with extended low-frequency response, and tone controls optimised for the needs of bass players.

Higher-toll bass amplifiers may include born bass effects units, such as audio compressor or limiter features, to avoid unwanted distorting at high volume levels and potential damage to speakers; equalizers; and bass overdrive.

Bass amps may provide an XLR DI output for plugging the bass amp signal directly into a mixing board or PA system. Larger, more than powerful bass amplifiers (300 or more watts) are often provided with internal or external metal heat sinks and/or fans to help keep the components cool.

Speaker cabinets designed for bass usually utilize larger loudspeakers (or more loudspeakers, such as iv ten-inch speakers) than the cabinets used for other instruments, and then that they tin can motility the larger amounts of air needed to reproduce low frequencies. Bass players have to apply more powerful amplifiers than the electrical guitarists, because deep bass frequencies take more power to amplify^{[ commendation needed ]}. While the largest speakers commonly used for regular electrical guitar have twelve-inch cones, electric bass speaker cabinets often use 15" speakers. Bass players who play styles of music that crave an extended low-range response, such every bit expiry metal, sometimes use speaker cabinets with 18" speakers or add a large subwoofer cabinet to their rig.

Speakers for bass instrument amplification tend to exist heavier-duty than those for regular electric guitar, and the speaker cabinets are typically more rigidly constructed and heavily braced, to prevent unwanted buzzes and rattles. Bass cabinets ofttimes include bass reflex ports, vents or openings in the chiffonier, which improve the bass response and low-end, especially at high volumes.

A modest keyboard amplifier suitable for calm practice capable of mixing the inputs from two keyboards.

Keyboard [edit]

A keyboard amplifier, used for the stage pianoforte, synthesizer, clonewheel organs and like instruments, is distinct from other types of amplification systems due to the particular challenges associated with keyboards; namely, to provide solid low-frequency sound reproduction and well-baked high-frequency audio reproduction. It is typically a combination amplifier that contains a two, three, or four-channel mixer, a pre-amplifier for each channel, equalization controls, a power amplifier, a speaker, and a horn, all in a single chiffonier.

Notable exceptions include keyboard amplifiers for specific keyboard types. The vintage Leslie speaker cabinet and modern recreations, which are more often than not used for Hammond organs, utilise a tube amplifier that is often turned upwardly to add together a warm, "growling" overdrive. Some electric pianos have built-in amplifiers and speakers, in improver to outputs for external amplification.

Acoustic amplifiers [edit]

These amplifiers are intended for acoustic instruments such as violin ("dabble"), mandolin, harp, and acoustic guitar—particularly for the way musicians play these instruments in quieter genres such every bit folk and bluegrass. They are similar to keyboard amplifiers, in that they take a relatively apartment frequency response and avoid tonal coloration.

To produce this relatively "clean" sound, these amplifiers frequently take very powerful amplifiers (up to 800 watts RMS), to provide additional "headroom" and prevent unwanted baloney. Since an 800 watt amplifier built with standard Class AB engineering would be heavy, some audio-visual amplifier manufacturers utilize lightweight Class D, "switching amplifiers."

Audio-visual amplifier designs strive to produce a clean, transparent, "acoustic" sound that does non—except for reverb and other effects—alter the natural instrument sound, other than to brand information technology louder. Amplifiers often come with a unproblematic mixer to blend signals from a pickup and microphone. Since the early 2000s, it is increasingly mutual for acoustic amplifiers to provided digital effects, such as reverb and compression. Some besides incorporate feedback-suppressing devices, such as notch filters or parametric equalizers.^[1]

Roles [edit]

Instrument amplifiers have a unlike purpose than 'Howdy-Fi' (high fidelity) stereo amplifiers in radios and abode stereo systems. Hi-fi home stereo amplifiers strive to accurately reproduce signals from pre-recorded music, with equally footling harmonic baloney as possible. In contrast, musical instrument amplifiers are add additional tonal coloration to the original signal or emphasize certain frequencies. For electric instruments such every bit electric guitar, the amplifier helps to create the instrument's tone by boosting the input signal gain and distorting the point, and past emphasizing frequencies deemed desirable (e.thousand., low frequencies) and de-emphasizing frequencies deemed undesirable (due east.chiliad., very high frequencies).

Size and power rating [edit]

In the 1960s and 1970s, large, heavy, high output power amplifiers were preferred for instrument amplifiers, especially for large concerts, because public accost systems were generally simply used to amplify the vocals. Moreover, in the 1960s, PA systems typically did non utilise monitor speaker systems to amplify the music for the onstage musicians. Instead, the musicians were expected to have instrument amplifiers that were powerful plenty to provide distension for the stage and audience. In belatedly 1960s and early on 1970s stone concerts, bands ofttimes used large stacks of speaker cabinets powered by heavy tube amplifiers such equally the Super Valve Technology (SVT) amplifier, which was oft used with eight x" speakers.

All the same, over subsequent decades, PA systems essentially improved, and used dissimilar approaches, such equally horn-loaded "bass bins" (in the 1980s) and subwoofers (1990s and 2000s) to dilate bass frequencies. Also, in the 1980s and 1990s, monitor systems essentially improved, which helped sound engineers provide onstage musicians with a better reproduction of their instruments' audio.

Every bit a result of improvements to PA and monitor systems, musicians in the 2000s no longer need huge, powerful amplifier systems. A minor combo amplifier patched into the PA suffices. In the 2000s, near all sound reaching the audition in large venues comes from the PA system. Onstage instrument amplifiers are more likely to be at a low book, because high book levels onstage make information technology harder for the audio engineer to command the sound mix.

Equally a result, in many big venues much of the onstage sound reaching the musicians at present comes from in-ear monitors, not from the instrument amplifiers. While stacks of huge speaker cabinets and amplifiers are still used in concerts (specially in heavy metal), this is frequently mainly for aesthetics or to create a more authentic tone. The switch to smaller instrument amplifiers makes it easier for musicians to send their equipment to performances. Equally well, information technology makes concert stage direction easier at large clubs and festivals where several bands are performing in sequence, because the bands can exist moved on and off the stage more apace.

Amplifier engineering science [edit]

Instrument amplifiers may exist based on thermionic ("tube" or "valve") or solid state (transistor) technology.

Tube amplifiers [edit]

Vacuum tubes were the ascendant agile electronic components in amplifiers from the 1930s through the early 1970s, and tube amplifiers remain preferred by many musicians and producers. Some musicians feel that tube amplifiers produce a "warmer" or more than "natural" sound than solid state units, and a more pleasing overdrive sound when overdriven. Notwithstanding, these subjective assessments of the attributes of tube amplifiers' sound qualities are the field of study of ongoing contend. Tube amps are more fragile, require more than maintenance, and are usually more expensive than solid country amps.

Tube amplifiers produce more heat than solid state amplifiers, but few manufacturers of these units include cooling fans in the chassis. While tube amplifiers practice need to attain a proper operating temperature, if the temperature goes to a higher place this operating temperature, information technology may shorten the tubes' lifespan and lead to tonal inconsistencies.^[2]

A Trace Elliot "Bonneville" tube amplifier as seen from the rear view: note the vacuum tubes extending into the wooden chiffonier.

Solid-land amplifiers [edit]

By the 1960s and 1970s, semiconductor transistor-based amplifiers began to become more popular considering they are less expensive, more resistant to bumps during transportation, lighter-weight, and require less maintenance. In some cases, tube and solid-state technologies are used together in amplifiers. A common setup is the utilize of a tube preamplifier with a solid-state power amplifier. There are as well an increasing range of products that use digital bespeak processing and digital modeling technology to simulate many unlike combinations of amp and cabinets.

The output transistors of solid-land amplifiers tin can exist passively cooled past using metallic fins called heatsinks to radiate away the oestrus. For high-wattage amplifiers (over 800 watts), a fan is oftentimes used to movement air beyond internal heatsinks.^[3]

Hybrid [edit]

The most mutual hybrid amp design is to use a tube preamp with a solid state ability amplifier. This gives users the pleasing preamp and overdrive tone of a tube amp with the lowered cost, maintenance and weight of a solid state power amp.

Wikimedia Eatables has media related to Guitar.

See also [edit]

• Amplifier
• Electronic amplifier
• Guitar amplifier
• Guitar speaker
• Guitar speaker cabinet
• Isolation cabinet (guitar)
• Valve sound
• Bass instrument amplification
• Effects unit
• Distortion (guitar)
• Ability attenuator (guitar)
• Sound reinforcement system

References [edit]

1. ^ Note: Acoustic amplifiers should not exist confused with the amplifier brand proper name Acoustic, whose products are nonetheless bachelor in the used equipment market place.)
2. ^ Cool it, man; Michael "Mac" McCullough.
3. ^ Ability Amplifiers - General Information: Yorkville Audio Archived 2010-10-07 at the Wayback Automobile

External links [edit]

• Duncan's amp pages: data about valve (tube) guitar amplifiers
• List of books about guitar amplifiers and guitar amplifier tone
• Tons of Tones, a website for guitar amplifier modelling on digital multi-result units

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Source: https://en.wikipedia.org/wiki/Instrument_amplifier

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