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67-488: The company was co-founded in 1949 by Frank H. McIntosh and Gordon Gow. McIntosh Labs designs and produces audio amplifiers , stereo tuners , loudspeakers , turntables , music streamers, processors, and various other audio products. Although solid state components are a large segment of the McIntosh line, audio enthusiasts most revere the warm sound of the company's tube amplifiers . Some of their tube amplifiers rank among

134-455: A transformer where one winding is used to control the saturation of a magnetic core and hence alter the impedance of the other winding. They have largely fallen out of use due to development in semiconductor amplifiers but are still useful in HVDC control, and in nuclear power control circuitry due to not being affected by radioactivity. Negative resistances can be used as amplifiers, such as

201-646: A transmission line at input and output, especially RF amplifiers , do not fit into this classification approach. Rather than dealing with voltage or current individually, they ideally couple with an input or output impedance matched to the transmission line impedance, that is, match ratios of voltage to current. Many real RF amplifiers come close to this ideal. Although, for a given appropriate source and load impedance, RF amplifiers can be characterized as amplifying voltage or current, they fundamentally are amplifying power. Amplifier properties are given by parameters that include: Amplifiers are described according to

268-406: A vacuum tube or transistor . Negative feedback is a technique used in most modern amplifiers to increase bandwidth, reduce distortion, and control gain. In a negative feedback amplifier part of the output is fed back and added to the input in the opposite phase, subtracting from the input. The main effect is to reduce the overall gain of the system. However, any unwanted signals introduced by

335-690: A bipolar junction transistor can realize common base , common collector or common emitter amplification; a MOSFET can realize common gate , common source or common drain amplification. Each configuration has different characteristics. Vacuum-tube amplifiers (also known as tube amplifiers or valve amplifiers) use a vacuum tube as the active device. While semiconductor amplifiers have largely displaced valve amplifiers for low-power applications, valve amplifiers can be much more cost effective in high power applications such as radar, countermeasures equipment, and communications equipment. Many microwave amplifiers are specially designed valve amplifiers, such as

402-795: A broad spectrum of frequencies; however, they are usually not as tunable as klystrons. Klystrons are specialized linear-beam vacuum-devices, designed to provide high power, widely tunable amplification of millimetre and sub-millimetre waves. Klystrons are designed for large scale operations and despite having a narrower bandwidth than TWTAs, they have the advantage of coherently amplifying a reference signal so its output may be precisely controlled in amplitude, frequency and phase. Solid-state devices such as silicon short channel MOSFETs like double-diffused metal–oxide–semiconductor (DMOS) FETs, GaAs FETs , SiGe and GaAs heterojunction bipolar transistors /HBTs, HEMTs , IMPATT diodes , and others, are used especially at lower microwave frequencies and power levels on

469-408: A higher bandwidth to be achieved than could otherwise be realised even with the same gain stage elements. These nonlinear amplifiers have much higher efficiencies than linear amps, and are used where the power saving justifies the extra complexity. Class-D amplifiers are the main example of this type of amplification. A negative resistance amplifier is a type of regenerative amplifier that can use

536-561: A large gain, and the output performance of the system (the "closed loop performance ") is defined entirely by the components in the feedback loop. This technique is used particularly with operational amplifiers (op-amps). Non-feedback amplifiers can achieve only about 1% distortion for audio-frequency signals. With negative feedback , distortion can typically be reduced to 0.001%. Noise, even crossover distortion, can be practically eliminated. Negative feedback also compensates for changing temperatures, and degrading or nonlinear components in

603-584: A long and illustrious history that saw them expand their business around the world, the company began to struggle and was ultimately acquired by Clarion , a large Japanese manufacturer of car stereo gear in 1990 for 28.6 million dollars. McIntosh components, particularly the early tube models, are highly regarded in Japan. In a speech shortly after the purchase, Clarion president Yutaka Oyamada told McIntosh employees that "we like McIntosh as it is, and we have no intention of changing what has made it so successful." After

670-648: A management buyout of the Fine Sounds Group from its Italian investment firm owner, Quadrivio Investment Group. Since then, Fine Sounds Group has renamed itself McIntosh Group and relocated from Milan to New York. McIntosh Group is a holding company for the brands McIntosh Laboratory, Sonus Faber , Sumiko Phono Cartridges, Fine Sounds Americas, Fine Sounds BeNelux, and Fine Sounds U.K. It has also partnered Sonus Faber with Maserati and partnered McIntosh Audio with Jeep . Jeff Poggi and Charlie Randall were named Co-CEO's in 2017 of McIntosh Group. Daniel Pidgeon

737-445: A signal chain (the output stage) and is the amplifier stage that requires attention to power efficiency. Efficiency considerations lead to the various classes of power amplifiers based on the biasing of the output transistors or tubes: see power amplifier classes below. Audio power amplifiers are typically used to drive loudspeakers . They will often have two output channels and deliver equal power to each. An RF power amplifier

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804-409: A single chip thereby creating higher scales of integration (such as small-scale, medium-scale and large-scale integration ) in integrated circuits . Many amplifiers commercially available today are based on integrated circuits. For special purposes, other active elements have been used. For example, in the early days of the satellite communication , parametric amplifiers were used. The core circuit

871-466: A total of 28,800 watts of continuous power to power a speaker system over 100 feet wide and three stories tall. In October 1977, Gordon Gow became president and CEO when Mr. McIntosh retired. Mr. McIntosh sold his stock shares to top management and a few dedicated McIntosh investors. He was retained with a salary on a consulting basis. He moved from his home in Endicott, NY to Scottsdale, Arizona After

938-1065: Is a trademark of McIntosh Laboratory, Inc. and is being used with express permission of its owner. Label on the back of the Macintosh Plus 1Mb computer 1949: Tubed Unity Coupled 50W1 Power Amplifier. 1955: C8 Audio Compensator preamplifier Late 1960s: MC 2505 First Transistor amp utilizing Autoformer technology. Late 1960s: MC 3500 Tube Power Amplifier, 350 WPC. Early 1970s: MC 2300 Power Amplifier , 300 WPC. Early 1980s: MC 2500 Power Amplifier, 500 WPC Power Guard and similar chassis to MC 2300. Around 1990: MC 2600 Power Amplifier, 600 WPC Power Guard final version on MC 2300 Chassis. Around 1990: MC 7300, 300 WPC and much smaller than MC 2300. Around 2006: MC2KW 2000WPC 3 Chassis Quad Balanced Amplifier. Around 2008: MT10 Precision Turntable. Around 2017: MC1.25KW, 1200 WPC Single Chassis Quad balanced Amp. Around 2019: MA352 Integrated Hybrid Amplifier Around 2019: MC3500 MkII 350 WPC Mono Vacuum Tube Amp inspired by

1005-428: Is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current ). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) 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

1072-446: Is by the frequency of the electronic signal being amplified. For example, audio amplifiers amplify signals in the audio (sound) range of less than 20 kHz, RF amplifiers amplify frequencies in the radio frequency range between 20 kHz and 300 GHz, and servo amplifiers and instrumentation amplifiers may work with very low frequencies down to direct current. Amplifiers can also be categorized by their physical placement in

1139-514: Is found in radio transmitter final stages. A servo motor controller amplifies a control voltage to adjust the speed of a motor, or the position of a motorized system. An operational amplifier is an amplifier circuit which typically has very high open loop gain and differential inputs. Op amps have become very widely used as standardized "gain blocks" in circuits due to their versatility; their gain, bandwidth and other characteristics can be controlled by feedback through an external circuit. Though

1206-457: Is measured by its gain : the ratio of output voltage, current, or power to input. An amplifier is defined as a circuit that has a power gain greater than one. An amplifier can be either a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categorized in different ways. One

1273-409: Is most often configured to provide amplification of a voltage applied between base and emitter, and the output signal taken between collector and emitter is inverted, relative to the input. The common collector arrangement applies the input voltage between base and collector, and to take the output voltage between emitter and collector. This causes negative feedback, and the output voltage tends to follow

1340-413: Is said to have a gain of 20 dB might have a voltage gain of 20 dB and an available power gain of much more than 20 dB (power ratio of 100)—yet actually deliver a much lower power gain if, for example, the input is from a 600 Ω microphone and the output connects to a 47  kΩ input socket for a power amplifier. In general, the power amplifier is the last 'amplifier' or actual circuit in

1407-620: Is the Pryma 0/1, which comes with six variations of headbands and seven variations of earcups. In 2016, they released the Pryma Aria, a wireless version of the 0/1. In 2019, Sonus faber announced the Palladio collection, a brand new range of custom in-wall and in-ceiling speakers for the audiophiles with a desire for a home theatre system. In 2020, Maserati announced the MC20 would include

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1474-505: Is the current CEO of McIntosh Group (since June 2022). Charlie Randall is the current President of McIntosh Laboratory (since 2001). A Dallas-based Private Investment firm, Highlander Partners, acquired McIntosh Group (which includes McIntosh Laboratory) as part of their equity portfolio in June 2022. McIntosh Laboratory's revenue was $ 25 million and $ 42 million in 2021 and 2022, respectively. On 19 November 2024, Highlander Partners announced

1541-402: Is the device that does the actual amplification. The active device can be a vacuum tube , discrete solid state component, such as a single transistor , or part of an integrated circuit , as in an op-amp . Transistor amplifiers (or solid state amplifiers) are the most common type of amplifier in use today. A transistor is used as the active element. The gain of the amplifier is determined by

1608-430: Is useful. Certain signal processing applications use exponential gain amplifiers. Amplifiers are usually designed to function well in a specific application, for example: radio and television transmitters and receivers , high-fidelity ("hi-fi") stereo equipment, microcomputers and other digital equipment, and guitar and other instrument amplifiers . Every amplifier includes at least one active device , such as

1675-480: The Class-D amplifier . In principle, an amplifier is an electrical two-port network that produces a signal at the output port that is a replica of the signal applied to the input port, but increased in magnitude. The input port can be idealized as either being a voltage input, which takes no current, with the output proportional to the voltage across the port; or a current input, with no voltage across it, in which

1742-533: The Woodstock Music Festival in 1969. A battery of twenty McIntosh MC3500 tube amplifiers were used to power the JBL speakers at Woodstock for the 400,000+ fans in attendance. Urban legend has it that these amps needed to be cooled by ice on the hot August days so they would not overheat but McIntosh Laboratory Inc President, Charlie Randall, dismissed the tale as folk lore saying "Any ice packed around

1809-475: The bipolar junction transistor (BJT) in 1948. They were followed by the invention of the metal–oxide–semiconductor field-effect transistor (MOSFET) by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959. Due to MOSFET scaling , the ability to scale down to increasingly small sizes, the MOSFET has since become the most widely used amplifier. The replacement of bulky electron tubes with transistors during

1876-412: The klystron , gyrotron , traveling wave tube , and crossed-field amplifier , and these microwave valves provide much greater single-device power output at microwave frequencies than solid-state devices. Vacuum tubes remain in use in some high end audio equipment, as well as in musical instrument amplifiers , due to a preference for " tube sound ". Magnetic amplifiers are devices somewhat similar to

1943-503: The signal chain ; a preamplifier may precede other signal processing stages, for example, while a power amplifier is usually used after other amplifier stages to provide enough output power for the final use of the signal. The first practical electrical device which could amplify was the triode vacuum tube , invented in 1906 by Lee De Forest , which led to the first amplifiers around 1912. Today most amplifiers use transistors . The first practical prominent device that could amplify

2010-514: The tunnel diode amplifier. A power amplifier is an amplifier designed primarily to increase the power available to a load . In practice, amplifier power gain depends on the source and load impedances , as well as the inherent voltage and current gain. A radio frequency (RF) amplifier design typically optimizes impedances for power transfer, while audio and instrumentation amplifier designs normally optimize input and output impedance for least loading and highest signal integrity. An amplifier that

2077-415: The 1960s and 1970s created a revolution in electronics, making possible a large class of portable electronic devices, such as the transistor radio developed in 1954. Today, use of vacuum tubes is limited to some high power applications, such as radio transmitters , as well as some musical instrument and high-end audiophile amplifiers. Beginning in the 1970s, more and more transistors were connected on

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2144-597: The 50th Anniversary of the MC3500 that powered Woodstock. Around 2020: MA12000, 350 WPC Hybrid Tube/SS Integrated Amp (most powerful tube/solid state integrated amp from Mcintosh to date) Around 2023: MC451, 150WPC/300 WPC Hybrid Tube/SS Integrated Amp Around 2023: PS2k Powered Subwoofer 09/03/2013 D100 Digital Preamp Receives AVforums.com "HIGHLY RECOMMENDED" Award. 04/02/2015 MA8000 Integrated Amplifier named "Best Amplifier" by Hi-Fi World. 06/05/2015 MA8000 Integrated Amplifier named "High End Stereo Amplifier of

2211-585: The Clarion purchase, McIntosh expanded into car audio and home theater. In May 2003, Clarion sold McIntosh Laboratory to D&M Holdings also of Japan. The company continued to operate independent engineering, design, and divisions. On October 8, 2012, Fine Sounds SpA of Milan, Italy, announced it had purchased McIntosh. In May 2014, the CEO of Fine Sounds Group, along with the President of McIntosh Labs, led

2278-810: The Year" by Absolute Sound. 12/15/2016 RS100 Wireless Speaker Wins "Diapason d'Or" Hi-Fi Award. 02/08/2017 MC275 Vacuum Tube Amplifier & C22 Vacuum Tube preamplifier win Absolute Sound's "Editor's Choice" award. 06/02/2017 MCD550 SACD/CD player wind "Outstanding Product Award" by Speaker Shack. 08/02/2017 MT5 Turntable wins "Top Quality" award from Fedelta del Suono. 11/15/2017 MC1.25KW Amplifier & MA9000 Integrated Amp win Stereo Sound's "Grand Prix" Awards. 11/17/2017 MA8900 Integrated Amplifier Wins "Diapason d'Or" award. Amplifiers An amplifier , electronic amplifier or (informally) amp

2345-505: The Year" by Lyd & Bilde. 11/25/2015 MA5200 Integrated Amplifier Wins "Diapason d'Or" Award. 12/09/2015 MC452 Amplifier and C2500 preamplifier win Sound+Image Award. 02/10/2016 C1100 Preamplifier Wins "Stereo Sound Grand Prix Award". 02/24/2016 MCD550 SACD/CD player named product of the year by HiFi Review. 03/03/2016 MC152 named "Best Amplifier" by HiFi World. 11/22/2016 C22 Vacuum Tube Preamplifier named "Product of

2412-451: The amplifier specifications and size requirements microwave amplifiers can be realised as monolithically integrated, integrated as modules or based on discrete parts or any combination of those. The maser is a non-electronic microwave amplifier. Instrument amplifiers are a range of audio power amplifiers used to increase the sound level of musical instruments, for example guitars, during performances. An amplifier's tone mainly comes from

2479-447: The amplifier, such as distortion are also fed back. Since they are not part of the original input, they are added to the input in opposite phase, subtracting them from the input. In this way, negative feedback also reduces nonlinearity, distortion and other errors introduced by the amplifier. Large amounts of negative feedback can reduce errors to the point that the response of the amplifier itself becomes almost irrelevant as long as it has

2546-622: The amps in the middle of August would have quickly melted and the resulting water would have caused massive issues with the electronics". On March 23, 1974, the Grateful Dead's "Wall of Sound" debuted at the Cow Palace in Daly City, CA (and then subsequently on other tour locations). It reportedly used forty-eight 300-watt per channel (600 wpc in a bridged monoblock configuration) McIntosh model MC2300 solid state amplifiers for

2613-669: The components in the feedback loop. Negative feedback can be applied at each stage of an amplifier to stabilize the operating point of active devices against minor changes in power-supply voltage or device characteristics. Some feedback, positive or negative, is unavoidable and often undesirable—introduced, for example, by parasitic elements , such as inherent capacitance between input and output of devices such as transistors, and capacitive coupling of external wiring. Excessive frequency-dependent positive feedback can produce parasitic oscillation and turn an amplifier into an oscillator . All amplifiers include some form of active device: this

2680-409: The distortion levels to be greatly reduced, at the cost of lower gain. Other advances in the theory of amplification were made by Harry Nyquist and Hendrik Wade Bode . The vacuum tube was virtually the only amplifying device, other than specialized power devices such as the magnetic amplifier and amplidyne , for 40 years. Power control circuitry used magnetic amplifiers until the latter half of

2747-562: The employees working at the Binghamton plant have been with the company for decades and number approximately 170+ as of June, 2022. McIntosh audio products can usually be recognized by their black glass front panels (circa 1960's to present), iconic blue VU meters (circa 1974 to present), and iconic gothic logo. The Mcintosh factory has a black facade with blue tinted windows to align with the company's trademark theme. Frank H. McIntosh and Gordon Gow co-founded McIntosh in 1949. The company

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2814-449: The feedback between the transistor's source and gate to transform a capacitive impedance on the transistor's source to a negative resistance on its gate. Compared to other types of amplifiers, a negative resistance amplifier will require only a tiny amount of power to achieve very high gain, maintaining a good noise figure at the same time. Video amplifiers are designed to process video signals and have varying bandwidths depending on whether

2881-425: The finest ever created for home audio and theater use. Their Unity Coupled Circuit, patented at the brand's inception, is still used today in products like their MC275 amplifier, whose vacuum tubes—used in many of the company's products—help to impart a lifelike warmth and soul to the sound. "McIntosh transformers are hand-wound in house as they've always been" according to McIntosh president, Charlie Randall. Many of

2948-525: The first computers . For 50 years virtually all consumer electronic devices used vacuum tubes. Early tube amplifiers often had positive feedback ( regeneration ), which could increase gain but also make the amplifier unstable and prone to oscillation. Much of the mathematical theory of amplifiers was developed at Bell Telephone Laboratories during the 1920s to 1940s. Distortion levels in early amplifiers were high, usually around 5%, until 1934, when Harold Black developed negative feedback ; this allowed

3015-469: The four types of dependent source used in linear analysis, as shown in the figure, namely: Each type of amplifier in its ideal form has an ideal input and output resistance that is the same as that of the corresponding dependent source: In real amplifiers the ideal impedances are not possible to achieve, but these ideal elements can be used to construct equivalent circuits of real amplifiers by adding impedances (resistance, capacitance and inductance) to

3082-446: The gain stage, but any change or nonlinearity in the components in the feedback loop will affect the output. Indeed, the ability of the feedback loop to define the output is used to make active filter circuits . Another advantage of negative feedback is that it extends the bandwidth of the amplifier. The concept of feedback is used in operational amplifiers to precisely define gain, bandwidth, and other parameters entirely based on

3149-427: The input and output. For any particular circuit, a small-signal analysis is often used to find the actual impedance. A small-signal AC test current I x is applied to the input or output node, all external sources are set to AC zero, and the corresponding alternating voltage V x across the test current source determines the impedance seen at that node as R = V x / I x . Amplifiers designed to attach to

3216-542: The input voltage. This arrangement is also used as the input presents a high impedance and does not load the signal source, though the voltage amplification is less than one. The common-collector circuit is, therefore, better known as an emitter follower, source follower, or cathode follower. Sonus Faber Sonus faber is an Italian manufacturer of handcrafted speakers, headphones, and other high-end audio equipment based in Arcugnano , Veneto , Italy . The company

3283-560: The need to increase the amplitude of electrical signals to extend the transmission of signals over increasingly long distances. In telegraphy , this problem had been solved with intermediate devices at stations that replenished the dissipated energy by operating a signal recorder and transmitter back-to-back, forming a relay , so that a local energy source at each intermediate station powered the next leg of transmission. For duplex transmission, i.e. sending and receiving in both directions, bi-directional relay repeaters were developed starting with

3350-554: The order and amount in which it applies EQ and distortion. One set of classifications for amplifiers is based on which device terminal is common to both the input and the output circuit. In the case of bipolar junction transistors , the three classes are common emitter, common base, and common collector. For field-effect transistors , the corresponding configurations are common source, common gate, and common drain; for vacuum tubes , common cathode, common grid, and common plate. The common emitter (or common source, common cathode, etc.)

3417-512: The order of watts specifically in applications like portable RF terminals/ cell phones and access points where size and efficiency are the drivers. New materials like gallium nitride ( GaN ) or GaN on silicon or on silicon carbide /SiC are emerging in HEMT transistors and applications where improved efficiency, wide bandwidth, operation roughly from few to few tens of GHz with output power of few watts to few hundred of watts are needed. Depending on

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3484-447: The output is proportional to the current through the port. The output port can be idealized as being either a dependent voltage source , with zero source resistance and its output voltage dependent on the input; or a dependent current source , with infinite source resistance and the output current dependent on the input. Combinations of these choices lead to four types of ideal amplifiers. In idealized form they are represented by each of

3551-414: The outputs of which are summed by the same transmission line. The transmission line is a balanced type with the input at one end and on one side only of the balanced transmission line and the output at the opposite end is also the opposite side of the balanced transmission line. The gain of each stage adds linearly to the output rather than multiplies one on the other as in a cascade configuration. This allows

3618-571: The properties of the transistor itself as well as the circuit it is contained within. Common active devices in transistor amplifiers include bipolar junction transistors (BJTs) and metal oxide semiconductor field-effect transistors (MOSFETs). Applications are numerous. Some common examples are audio amplifiers in a home stereo or public address system , RF high power generation for semiconductor equipment, to RF and microwave applications such as radio transmitters. Transistor-based amplification can be realized using various configurations: for example

3685-422: The properties of their inputs, their outputs, and how they relate. All amplifiers have gain, a multiplication factor that relates the magnitude of some property of the output signal to a property of the input signal. The gain may be specified as the ratio of output voltage to input voltage ( voltage gain ), output power to input power ( power gain ), or some combination of current, voltage, and power. In many cases

3752-410: The property of the output that varies is dependent on the same property of the input, making the gain unitless (though often expressed in decibels (dB)). Most amplifiers are designed to be linear. That is, they provide constant gain for any normal input level and output signal. If an amplifier's gain is not linear, the output signal can become distorted . There are, however, cases where variable gain

3819-577: The sale of McIntosh Group to Bose Corporation, headquartered in Framingham, Massachusetts. Bose Corporation did not disclose the dollar amount for the purchase in its press release but confirmed Bose had purchased Mcintosh and Sonus faber. Bose was founded in 1964 by Dr. Amar Bose and continues to design and manufacture home, portable, and automotive audio equipment. Apple and the Apple logo are registered trademarks of Apple Computer, Inc. Macintosh

3886-418: The term today commonly applies to integrated circuits, the original operational amplifier design used valves, and later designs used discrete transistor circuits. A fully differential amplifier is similar to the operational amplifier, but also has differential outputs. These are usually constructed using BJTs or FETs . These use balanced transmission lines to separate individual single stage amplifiers,

3953-508: The twentieth century when power semiconductor devices became more economical, with higher operating speeds. The old Shreeve electroacoustic carbon repeaters were used in adjustable amplifiers in telephone subscriber sets for the hearing impaired until the transistor provided smaller and higher quality amplifiers in the 1950s. The first working transistor was a point-contact transistor invented by John Bardeen and Walter Brattain in 1947 at Bell Labs , where William Shockley later invented

4020-462: The video signal is for SDTV, EDTV, HDTV 720p or 1080i/p etc. The specification of the bandwidth itself depends on what kind of filter is used—and at which point ( −1 dB or −3 dB for example) the bandwidth is measured. Certain requirements for step response and overshoot are necessary for an acceptable TV image. Traveling wave tube amplifiers (TWTAs) are used for high power amplification at low microwave frequencies. They typically can amplify across

4087-478: The work of C. F. Varley for telegraphic transmission. Duplex transmission was essential for telephony and the problem was not satisfactorily solved until 1904, when H. E. Shreeve of the American Telephone and Telegraph Company improved existing attempts at constructing a telephone repeater consisting of back-to-back carbon-granule transmitter and electrodynamic receiver pairs. The Shreeve repeater

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4154-461: Was a diode whose capacitance was changed by an RF signal created locally. Under certain conditions, this RF signal provided energy that was modulated by the extremely weak satellite signal received at the earth station. Advances in digital electronics since the late 20th century provided new alternatives to the conventional linear-gain amplifiers by using digital switching to vary the pulse-shape of fixed amplitude signals, resulting in devices such as

4221-447: Was first tested on a line between Boston and Amesbury, MA, and more refined devices remained in service for some time. After the turn of the century it was found that negative resistance mercury lamps could amplify, and were also tried in repeaters, with little success. The development of thermionic valves which began around 1902, provided an entirely electronic method of amplifying signals. The first practical version of such devices

4288-463: Was founded in 1983 by Franco Serblin . Sonus faber is one of several audio brands owned by McIntosh Group , which also owns McIntosh, Sumiko, and Fine Sounds . Sonus faber's products include Chameleon T floor-standing tower speakers, Venere floor speakers, Lumina bookshelf speakers, Aida tower speakers, and others. The Aida line of speakers sells for approximately $ 120,000. In 2015, Sonus faber introduced its portable headphone range Pryma. There

4355-585: Was originally located in Silver Spring MD. It moved to Binghamton NY in 1951. Dave O'Brien joined McIntosh in 1962. He led the McIntosh Amplifier Clinics for the next 29 years. Dave retired on June 11, 1999, after 38 years of service with McIntosh. In 1965, Mcintosh amps were used to power President Lyndon B. Johnson ’s inauguration speech. McIntosh created a Loudspeaker division in 1967. McIntosh amplifiers were used at

4422-851: Was the Audion triode , invented in 1906 by Lee De Forest , which led to the first amplifiers around 1912. Since the only previous device which was widely used to strengthen a signal was the relay used in telegraph systems, the amplifying vacuum tube was first called an electron relay . The terms amplifier and amplification , derived from the Latin amplificare , ( to enlarge or expand ), were first used for this new capability around 1915 when triodes became widespread. The amplifying vacuum tube revolutionized electrical technology. It made possible long-distance telephone lines, public address systems , radio broadcasting , talking motion pictures , practical audio recording , radar , television , and

4489-432: Was the triode vacuum tube , invented in 1906 by Lee De Forest , which led to the first amplifiers around 1912. Vacuum tubes were used in almost all amplifiers until the 1960s–1970s when transistors replaced them. Today, most amplifiers use transistors, but vacuum tubes continue to be used in some applications. The development of audio communication technology in form of the telephone , first patented in 1876, created

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