An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the power of a signal. It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is a circuit that has a power gain greater than one.
An audio power amplifier is an electronic amplifier that amplifies low-power electronic audio signals such as the signal from radio receiver or electric guitar pickup to a level that is high enough for driving loudspeakers or headphones. 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. It is the final electronic stage in a typical audio playback chain before the signal is sent to the loudspeakers.
Audio power is the electrical power transferred from an audio amplifier to a loudspeaker, measured in watts. The electrical power delivered to the loudspeaker, together with its efficiency, determines the sound power generated.
Nakamichi Corp., Ltd. is a Japanese consumer electronics brand that originated in Japan and gained a name from the 1970s onwards for innovative and high quality audio cassette decks. Nakamichi is a subsidiary of Chinese holding company Nimble Holdings.
A guitar amplifier 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. A guitar amplifier may be a standalone wood or metal cabinet that contains only the power amplifier 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. There is a wide range of sizes and power ratings for guitar amplifiers, from small, lightweight "practice amplifiers" with a single 6" speaker and a 10 watt amp to heavy combo amps with four 10” or four 12" speakers and a powerful 100 watt amplifier, which are loud enough to use in a nightclub or bar performance.
A public address system is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment. It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound source or recorded sound or music. PA systems are used in any public venue that requires that an announcer, performer, etc. be sufficiently audible at a distance or over a large area. Typical applications include sports stadiums, public transportation vehicles and facilities, and live or recorded music venues and events. A PA system may include multiple microphones or other sound sources, a mixing console to combine and modify multiple sources, and multiple amplifiers and loudspeakers for louder volume or wider distribution.
Mark Levinson is an American high-end audio equipment brand established in 1972 by eponymous founder Mark Levinson, and based in Stamford, Connecticut. It is owned by Harman International Industries, a subsidiary of South Korean company Samsung Electronics.
Klipsch Audio Technologies is an American loudspeaker company based in Indianapolis, Indiana. Founded in Hope, Arkansas, in 1946 as 'Klipsch and Associates' by Paul W. Klipsch, the company produces loudspeaker drivers and enclosures, as well as complete loudspeakers for high end, high fidelity sound systems, public address applications, and personal computers.
PS Audio is an American company specializing in high-fidelity audio components equipment for audiophiles and the sound recording industry. It currently produces audio amplifiers, preamplifiers, power related products, digital-to-analog converters, streaming audio, music management software and cables.
Mesa/Boogie is an American company in Petaluma, California, that manufactures amplifiers for guitars and basses. It has been in operation since 1969.
Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, Dynaco was an American hi-fi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components.. Its best known product was the ST-70 tube stereo amplifier. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd.
A class-D amplifier or switching amplifier is an electronic amplifier in which the amplifying devices operate as electronic switches, and not as linear gain devices as in other amplifiers. They operate by rapidly switching back and forth between the supply rails, being fed by a modulator using pulse width, pulse density, or related techniques to encode the audio input into a pulse train. The audio escapes through a simple low-pass filter into the loudspeaker. The high-frequency pulses are blocked. Since the pairs of output transistors are never conducting at the same time, there is no other path for current flow apart from the low-pass filter/loudspeaker. For this reason, efficiency can exceed 90%.
A single-ended triode (SET) is a vacuum tube electronic amplifier that uses a single triode to produce an output, in contrast to a push-pull amplifier which uses a pair of devices with antiphase inputs to generate an output with the wanted signals added and the distortion components subtracted. Single-ended amplifiers normally operate in Class A; push-pull amplifiers can also operate in Classes AB or B without excessive net distortion, due to cancellation.
Gainclone or chipamp is a type of audio amplifier made by do-it-yourselfers, or individuals interested in DIY audio. It is a design based on high-power integrated circuits, particularly the National Semiconductor Overture series. The Gainclone is probably the most commonly built and well-known amplifier project amongst hobbyists. It is simple to build and involves only a few readily accessible, inexpensive parts. As an amplifier it is highly regarded by many in the DIY community.
Nelson Pass is a designer of audio amplifiers. Pass is vocal that listening tests remain valuable and that electrical measurements alone do not fully characterize the sound of an amplifier. Pass holds at least seven U.S. patents related to audio circuits.
Virtue Audio is a manufacturer of integrated amplifiers based on the Tripath microprocessor chip, also known as a, class-T, class D or switching amplifier. The company produces unusually small, brightly colored, value-priced amplifiers that produce higher wattage than normally found at their price. Design consultants include Roger Sheker, chief engineer for high-end audio company Audience, maker of the Auricap capacitor.
Phonocar is an Italian Company, founded in Reggio Emilia, Italy, in 1972. Phonocar started with the production of wooden car-radio consoles and gradually specialized in car hi-fi speakers, amplifiers, audio-video equipment, security systems and related accessories. Phonocar products are distributed under her trademarks Phonocar, Sec, Mlife and Galileo.
Tube sound is the characteristic sound associated with a vacuum tube amplifier, a vacuum tube-based audio amplifier. At first, the concept of tube sound did not exist, because practically all electronic amplification of audio signals was done with vacuum tubes and other comparable methods were not known or used. After introduction of solid state amplifiers, tube sound appeared as the logical complement of transistor sound, which had some negative connotations due to crossover distortion in early transistor amplifiers. The audible significance of tube amplification on audio signals is a subject of continuing debate among audio enthusiasts.
Threshold Audio is a high-end audio equipment manufacturer originally established in California in 1974 by audio engineer Nelson Pass and graphic designer Rene Besne. The company, today based in Houston Texas, manufactures mono-block and stereo power amplifiers, multi-channel power amplifiers and stereo control amplifiers.
In electronics, power amplifier classes are letter symbols applied to different power amplifier types. The class gives a broad indication of an amplifier's characteristics and performance. The classes are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a signal waveform applied to the input. A class A amplifier is conducting through all the period of the signal; Class B only for one-half the input period, class C for much less than half the input period. A Class D amplifier operates its output device in a switching manner; the fraction of the time that the device is conducting is adjusted so a pulse width modulation output is obtained from the stage.
