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Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. | Tube sound (or valve sound) is the characteristic sound traditionally associated with a tube-based audio amplifier. All practical amplifiers distort to some degree; some audiophiles prefer the sound that is produced by the distortion characteristics of tube-based amplifiers. The audible significance of measurable effects on signals is a continuing debate among audiophiles. Image File history File links Emblem-important. ...
A valve amplifier (British English), also known as a tube amplifier or vacuum tube amplifier (in American English), is a device for electrically increasing the power of an electrical signal, typically sound. ...
A valve amplifier (UK and Aus. ...
Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ...
Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ...
Mission Cyrus 1 Hi Fi integrated audio amplifier An audio amplifier is an electronic amplifier that amplifies low-power audio signals (signals composed primarily of frequencies between 20 hertz to 20,000 hertz, the human range of hearing) to a level suitable for driving loudspeakers and is the final stage...
An audiophile, from Latin audire[1] to hear and Greek philos[2] loving, can be generally defined as a person dedicated to achieving high fidelity in the recording and playback of music . ...
History
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Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. | Before the commercial introduction of transistors in the 1950s, electronic amplifiers used vacuum tubes (a.k.a. "valves"). By the 1960s, solid state (transistorized) amplification has became more common because of its smaller size, lighter weight, lower heat production, and improved reliability. Tube amplifiers have retained a loyal following amongst some audiophiles and musicians. Some tube designs command very high prices. Image File history File links Question_book-3. ...
For the British rock band of the same name, see Amplifier (band). ...
In electronics, solid state circuits are those that do not contain vacuum tubes. ...
An audiophile, from Latin audire[1] to hear and Greek philos[2] loving, can be generally defined as a person dedicated to achieving high fidelity in the recording and playback of music . ...
Tube-amplifiers have been going through a revival since the opening up of Chinese and Russian markets where the production of tubes has never stopped.
Some musicians performing on electric guitar, electric bass, and keyboards in a range of popular and jazz genres continue to use tube instrument amplifiers or preamplifiers. An instrument amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ...
Explanation Tube sound is present in two distinct fields:
Sound reproduction Some audiophiles[attribution needed] state that the sound produced with tube amplifiers is more natural than the sound from typical transistor amplifiers, and for this reason more satisfying. Typically, in sound reproduction systems, accurate reproduction of the sound of the original recording is the goal; gross distortion is something designers do not deliberately seek to introduce. At the upper end of audio systems ("high end" or "audiophile" systems) it is debated whether "accuracy" can best be described by measuring a "wide frequency response" and "low measured distortion levels" or whether highest quality reproduction is subjectively determined by listening alone. An audiophile, most generally, is a lover of sound or music, but the word is more commonly used about someone who cares about hi-fi playback of sound recordings, rather than live performances. ...
Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. ...
Sound reproduction is the electrical or mechanical re-creation and/or amplification of sound, often as music. ...
Designing is the art of making compromises. All designs distort to some degree. Some designers[attribution needed] seek a compromise in the nature of "benign" distortion, others in a design that measures well in standard bench tests. In the high end world where sales pressure relative to perceived performance is high, "how it sounds" can have greater importance than how it measures.
Musical instrument amplification Some musicians[attribution needed] also prefer the distortion characteristics of tubes over transistors for electric guitar, bass, and other instrument amplifiers. In this case, generating deliberate (and sometimes considerable, in the case of electric guitars) audible distortion is usually a specific goal. A musician is a person who plays or composes music. ...
In the world of guitar music and guitar amplification, distortion is actively sought, evaluated, and appreciatively discussed in its endless flavors. ...
Photo of transistor types (tape measure marked in centimeters) Transistor in the SMD form factor The transistor is a solid state semiconductor device used for amplification and switching. ...
An electric guitar An electric guitar is a type of guitar that uses pickups to convert the vibration of its steel-cored strings into electrical current, which is then amplified. ...
A sunburst-colored Precision Bass The electric bass guitar (or electric bass; pronounced , as in base) is a bass stringed instrument played with the fingers (either by plucking, slapping, popping, or tapping) or using a pick. ...
An instrument amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ...
- See also: Guitar effects and Power chord
Guitar effects are electronic devices that modify the tone, pitch, or sound of an electric guitar. ...
In music, a power chord is a bare fifth, or a similar chord, usually played on electric guitar with distortion. ...
Solid-state emulation The term can also be used to describe the sound created by specially-designed transistor amplifiers or digital modelling devices that try to closely emulate the characteristics of the tube sound.
Probable causes The "warmth" and "richness" typically associated with "tube sound" is said to be composed of higher levels of 2nd order harmonic distortion, common in single-ended designs resulting from the characteristics of the tube interacting with the inductance of the output transformer.
Some tube fans[attribution needed] attribute the "naturalness" of the perceived sound to the reduced number of components used by tube-amplifiers. This is especially so for single-ended triode amplifiers (SET). These are said to reduce the "smearing" of the sound; reducing the imperfections invariably introduced by each electronic component. Much emphasis is placed on phase linearity. This minimalism is not solely the domain of tube amplifiers; there are some transistor amplifiers producing results that are not dissimilar. The JFET, for example, behaves much like a triode in it's "ohmic" region.
Another advantage of most tube amplifier designs is the high input impedance, typically 100 killo-ohms in modern designs and as much one mega-ohm in classic designs. By contrast, transistor amplifiers for home use may have much lower input impedances, some as low as 20k-ohms. This implies that it requires more energy to excite the input of a typical transistor amplifier to any given voltage than it does a typical tube-amp. If sensitivity to small signals is a significant goal, then tube designs will typically out-perform transistor designs.
Negative feedback Commodity transistor amplifiers, especially from the 1980s, typically used large amounts of negative feedback. This allowed for a very low measure of total harmonic distortion. Typical tube amplifiers have little or no negative feedback applied, and in recent years there has been a tendency in transistor amplifiers to use less feedback and design more linear stages[citation needed]; a process which has again narrowed the sonic differences between tube and transistor designs.
Audible differences Some audiophiles[attribution needed] prefer the sound of tubes over transistors. This is partly a function of the circuit topologies typically used with tubes vs the circuit topologies typically used with transistors, as much as the gain devices themselves. Beyond circuit design, there are other differences such as the electronic characteristics of a triode and mosfet, or a tetrode and a bipolar transistor.
Some sonic qualities are easy to explain objectively based on an analysis of the distortion characteristics of the gain device and/or the circuit topology. For example, the triode SE gain stage produces a stereotypical monotonically decaying harmonic distortion spectrum[clarify] that is dominated by significant second order harmonics making the sound seem rich or even "fat".
However, other audible differences in sound have proven difficult to define or measure, and it is difficult to explain these sound differences in words as the vocabulary available to describe sound is rather limited -even though the underlying sonic effects may be real. Audiophiles often use words like 'warm', 'liquid', 'smooth' and 'midrange magic' to describe the sound from tube amplifiers.
Some[attribution needed] claim that the midrange reproduction is more extended and smoother with tube amplifiers, but that high frequencies are somewhat rolled off. Historically this was often the case due to limitations in capacitor performance. Modern audiophile grade tube amplifiers however, using modern and/or premium quality (and cost) capacitors can have frequency response that are essentially flat to octaves beyond the audio range, -3dB above 65kHz would be normal, above 85kHz is quite common
Similarly, some[attribution needed] would characterise "tube sound" as bass response with less power and/or less definition (perhaps even "sloppy" bass or a bass boom with some speakers.) This again can be explained by many tube amplifiers having relatively high output impedance (Z out) compared to transistor designs, due to the combination of both higher device impedance itself and typically reduced feedback margins (more feedback results in a lower Z out).
So for example a hypothetical design in two otherwise equal variants with just different amounts of feedback, might result in the higher feedback version having a "drier" midrange (due to reduced 2nd order harmonics due to greater reduction of distortion) but a "tighter" bass due lower output impedance. The speaker impedance divided by the Z out is sometimes referred to as the "damping factor" - the amplifier's ability to control the mechanical movement of the speaker.
In general terms the sound from a tube amplifier will typically have a softer attack and the bass frequencies will be more prominent giving a warmer and "less harsh" sound. Instrumentation such as pianos and vocals sound softer and "fatter" than with transistor amplifiers. But as noted the reasons for these effects are not simply and unavoidably related to the gain device type, today a good designer using either technology has to make synergistic design compromise choices. And the sonic differences are less stereotyped than they used to be as a result.
Harmonic content and distortion Triodes (and Mosfets) produce a monotonically decaying harmonic distortion spectrum.
Psychoacoustic effects include that the stronger, lower harmonic products tend to dominate and mask the sound of the weaker, higher harmonic products
Even order harmonics sound as musical chords (notably octaves), which subjectively makes the sound "richer". Odd order harmonics sound less pleasant. Aharmonic distortion is discordant and is often implicated in designs that sound "brash", "harsh", "brittle", etc.
Another factor is that the distortion content of class A circuits (SE or PP) typically monotonically reduces as the signal level is reduced, asymptotic to zero during quiet passages of music. For this reason class A amplifiers are especially desired for classical and acoustic music etc. cf. class B and AB amplifiers, for which the amplitude of the crossover distortion is more or less constant, and thus the distortion relative to signal in fact increases as the music gets quieter. Class A amplifiers measure best at low power, class AB and B amplifiers measure best just below max rated power.
Loudspeakers present a reactive load to an amplifier (capacitance, inductance and resistance). This impedance may vary in value with signal frequency and amplitude. This variable loading affects the amplifiers performance both because the amplifier has finite output impedance (it cannot keep its output voltage perfectly constant when the speaker load varies) and because the phase of the speaker load can change the stability margin of the amplifier. The influence of the speaker impedance is different between valve amplifers and transistor amplifiers, principally because valve amplifiers normally use output transformers and they tend to use relatively low feedback.
The design of speaker crossover networks and other electro-mechanical properties may result in a speaker with a very un-even impedance curve, for a nominal 8 ohm speaker, being as low as 6 ohms at some places and as high as 30-50 ohms elsewhere in the curve. An amplifier with little or no feedback will always perform poorly when faced with a speaker where little attention was paid to the impedance curve.
Tube and transistor amplifier designs compared There has been considerable debate over the characteristics of tubes versus bipolar junction transistors. Some audiophiles[attribution needed] have argued that the quadratic transconductance of tubes compared with the exponential transconductance of transistors is an important factor. This has not been proven. A bipolar junction transistor (BJT) is a type of transistor. ...
f(x) = x2 - x - 2 A quadratic function, in mathematics, is a polynomial function of the form , where are real numbers and . ...
Transconductance, also known as mutual conductance, is a property of certain electronic components. ...
The term exponential may refer to any of several topics in mathematics: Exponential distribution Exponential function Exponential growth, exponential decay Exponential time Matrix exponential Exponential map (in differential geometry) All relate in some fashion to exponents. ...
Some audiophiles[attribution needed] argue that devices are not as important as circuit topology. Triodes and MOSFETs have certain similarities in their transfer characteristics, whereas later forms of the tube, the tetrode and pentode, have quite different characteristics that are in some ways similar to the bipolar transistor. Despite this, eg MOSFET amplifier circuits typically do not reproduce tube sound any more than typical bipolar designs, due to the circuit topology differences between a typical tube design and a typical mosfet design. But there always exceptions: for example some very interesting designs such as the Zen series by Nelson Pass which can be found on the web. Look up circuit in Wiktionary, the free dictionary. ...
A Möbius strip, an object with only one surface and one edge; such shapes are an object of study in topology. ...
Simplified diagram of a triode. ...
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is by far the most common field-effect transistor in both digital and analog circuits. ...
This article does not cite any references or sources. ...
This article does not cite any references or sources. ...
Neslon Pass is a noted and widely respected designer of audio amplifiers. ...
Soft clipping Soft clipping is a very important aspect of tube sound especially for guitar amplifiers, although a HiFi amplifier should not normally ever be driven into clipping. A guitar combo amplifier A guitar amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ...
A tube amplifier will reproduce a wave relatively linearly to a point, and as the signal moves beyond the linear range of the tube (into overload), it distorts the signal with a smooth curve instead of a sudden, sharp-edged cutoff (or even ringing and/or lockup) as occurs with transistors. The harmonics added to the signal are of lower energy with soft clipping than hard clipping. However, soft clipping is not exclusive to tubes, it can be simulated in transistor circuits (below the point that real hard clipping would occur); see section "Intentional creation of distortion" below. Note also that tube circuits often have huge headroom (overload) margins due to the high voltages they run from, so hard clipping is in reality very rare in a tube stage itself. However core saturation in the output transformer may be "designed in" to some guitar amplifiers when driven hard, and/or the tube biasing may be designed so that the tube passes from class AB1 to class AB2 and starts to draw grid current etc. (these effects are perhaps beyond the scope of this article) Surface waves in water This article is about waves in the most general scientific sense. ...
For other uses, see Linear (disambiguation). ...
Overload can refer to: Electrical overload, a situation where an electrical machine or system is subjected to a greater load than it was designed for. ...
In everyday speech, to distort something is to force it out of its natural shape. ...
In acoustics and telecommunication, the harmonic of a wave is a component frequency of the signal that is an integral multiple of the fundamental frequency. ...
Valve sound is the sound either from a valve amplifier or a specially designed transistor amplifier. ...
Circuit design may also play an important role in the tube sound; tube circuits are often less complex and laid out differently. It is argued that simplicity is usually best, as the length and complexity can change the inductance and capacitance of a circuit. An electric current i flowing around a circuit produces a magnetic field and hence a magnetic flux Φ through the circuit. ...
Capacitance is a measure of the amount of electric charge stored (or separated) for a given electric potential. ...
A more complex circuit will have a more complex sonic / distortion characteristic. Minimalist DH-SEs for example typically have a dominant very simple harmonic distortion spectrum. Complex modern transistor designs often have low level but extremely complex harmonic distortion spectra.
Bandwidth Early tube amplifiers often had only limited bandwidth, in part due to the passive component technology available on a budget at the time, notably resistors. However modern / premium components make it easy to produce amplifiers that are essentially flat over the audio band, with -3db points at order of 6Hz to 70kHz, several octaves beyond the musical / audio range. Bandwidth is the difference between the upper and lower cutoff frequencies of, for example, a filter, a communication channel, or a signal spectrum, and is typically measured in hertz. ...
Resistor symbols (non-European) Resistor symbols (Europe, IEC) Axial-lead resistors on tape. ...
Negative feedback Tube amplifiers could not, and did not need to, use as much negative feedback (NFB) as transistor amplifiers due to the large phase shifts caused by the output transformers and their lower stage gains. While the absence of NFB slightly increases harmonic distortion, it avoids instability, as well as slew rate and bandwidth limitations imposed by dominant-pole compensation in transistor amplifiers. This article does not cite any references or sources. ...
Power supplies Early tube amplifiers usually used unregulated power supplies. This was due to the high cost associated with high-quality high-voltage power supplies. The typical anode supply was simply a rectifier, an inductor and a filter capacitor. When the tube amplifier was operated at high volume, the power supply voltage would dip, reducing power output and causing signal modulation. This dipping effect is known as "sag", which may be preferable to some electric guitarists (almost invariably using a class AB1 amplifier). Note that for a class A stage the average current does NOT sag, it is constant. For other uses, see High voltage (disambiguation). ...
Diagram of a zinc anode in a galvanic cell. ...
AC, half-wave and full wave rectified signals A rectifier is an electrical device, comprising one or more semiconductive devices (such as diodes) or vacuum tubes arranged for converting alternating current to direct current. ...
Television signal splitter consisting of a hi-pass filter (left) and a low-pass filter (right). ...
For other uses, see Volume (disambiguation). ...
A wall wart style variable DC power supply with its cover removed. ...
International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ...
In contrast, modern amplifiers often use high-quality, well-regulated power supplies. In theory, the output voltage remains constant, but in reality it never does - not least due to resistive losses in the cabling from the power supply to the gain stage. This problem is proportionately much worse in transistor amplifiers because they operate at low voltage and high current, whereas tube voltage amplification stages operate at low currents and high voltages. Ohmic losses are a function of current through resistance.
Push-pull amplifiers A Class A push-pull amplifier produces exceptionally low distortion for any given level of applied feedback, and also cancels the flux in the transformer cores, so this topology is seen by some[attribution needed] as the ultimate "engineering" approach to the tube hi-fi amplifier for use with normal speakers. Output power of as high as 15 watts can be achieved even with classic tubes such as the 2A3, see RCA data sheet, Oct 15, 1947. or 18 watts from the type 45. Classic pentodes such as the EL34 and KT88 can output as much as 60 and 100 watts respectively. Special types such as the V1505 can be used in designs rated at up to 1100 watts. See "An Approach to Audio Frequency Design", a collection of reference designs originally published by G.E.C. This topic has already been covered in electronic amplifier. ...
A single GWR autocoach capable of push-pull operation. ...
For other uses, see Distortion (disambiguation). ...
For the superhero, see Feedback (Dark Horse Comics). ...
flux in science and mathematics. ...
For other uses, see Transformer (disambiguation). ...
A loudspeaker is a device which converts an electrical signal into sound. ...
The majority of commercial HiFi amplifier designs are Class AB, in order to deliver greater power and efficiency, typically 12 - 25 watts upwards. Such designs will invariably use at least some NFB. High Fidelity is also the title of a book by Nick Hornby and a film directed by Stephen Frears, based upon Hornbys book. ...
Class A amplifiers tend to have very low distortion when used with small signals, and are very inefficient Class B amplifiers tend to be efficient but suffer from high distortion when used with small signals. ...
For delivered electrical power, see Electrical power industry. ...
The efficiency of an entity (a device, component, or system) in electronics and electrical engineering is defined as useful power output divided by the total electrical power consumed (a fractional expression). ...
Class AB push-pull topology is nearly universally used in tube amps for electric guitar applications. Whereas audiophile amps are primarily concerned with avoiding distortion, a guitar amp embraces it. When driven to their respective limits, tubes and transistors distort quite differently. Tubes clip more softly than transistors, allowing higher levels of distortion (which is sometimes desired by the guitarist) whilst still being able to distinguish the harmonies of a chord. This is because the soft profile of the tube amplifier's distortion means that the intermodulation products of the distortion are generally more closely related to the harmonies of the chord. An intermodulation product is the product of two signals mixed in a nonlinear device, such as a nonlinear amplifier It is usually f1+f2, f1-f2, 2f1-f2, 2f2-f1, 3f1-2f2, 3f2-2f1, and more sums and differences of the two frequencies and their harmonics. ...
Single-Ended Triode (SET) amplifiers SET amplifiers typically show poor measurements for distortion with a resistive load, have low output power, are inefficient, have poor damping factors and high measured harmonic distortion. But they perform very well in dynamic and impulse response. Also, SET-amplifiers allready sound very well at low powerlevels without the perceived need for higher soundlevels like transistor amplifiers often do. In audio system terminology the damping factor gives the ratio of the rated impedance of the loudspeaker to the source impedance. ...
The triode, despite being the oldest signal amplification device, also has the most linear transfer characteristic, and thus requires little or no negative feedback for acceptable distortion performance. NFB is used in most post 1950s amplifiers and although it usually reduces the measured distortion level, it results in an unpleasant combination of harmonics to some ears. Simplified diagram of a triode. ...
This article does not cite any references or sources. ...
The 1950s decade refers to the years 1950 to 1959 inclusive. ...
Audiophiles who prefer SET-amplifiers state that measured sound performance is a poor indicator of real world sound performance and distortionlevels are not the only criterium for good sound reproduction. There are measurements not using resistive load but actual loudspeakers to back this up. In the 1970s, designers started producing transistor amps with higher open loop gain to support a greater value of negative feedback. These amps produced near perfect measured results but some listeners[attribution needed] felt that these amplifiers sounded "cold" or "dull". In the following years, amplifiers were built with modest gain but good open loop linearity, deployed with only minimal levels of NFB. An open-loop controller does not use feedback to control states or outputs of a dynamic system. ...
This article does not cite any references or sources. ...
All amplifiers do distort, so do SET's. This for the most part harmonic distortion is a distortion with a unique pattern of simple and monotonically decaying series of harmonics, dominated by modest levels of second harmonic. The result is like adding the same tone one octave higher. The added harmonic tone is lower, at about 1-5% or less in a no feedback amp at full power and rapidly decresing at lower levels. Some[attribution needed] argue that this "distortion" can actually enhance the music, just like the body of a musical instrument does, making it sound somewhat richer. This article is about the components of sound. ...
This article is about the components of sound. ...
For other uses, see Octave (disambiguation). ...
SETs usually only produce about 2 watts for a 2A3 tube amp to 8W for a 300B upto the practical maximum of 40W for a 805 tube amp. The most expensive amp in existence, the Wavac SH-833 monoblock SETs (which cost about US$350,000) produces about 150 watts using an 833A tube. Large amounts of power are not necessary in amplifiers, as only a few watts are required to drive most audiophile speakers to a SPL of about 100 dB at listening position (2-3 m). This depends on the sensitivity of the loudspeaker and the size and acoustics of the room. Their low power also makes them ideal for use as preamps. Watts may refer to: Watt, the SI derived unit of power Watts and Co. ...
An RCA Radiotron 833A with heat sink connectors The 833A is a vacuum tube constructed for high power radio frequency transmitter applications. ...
A preamplifier (preamp), as its name suggests, is an amplifier which precedes another amplifier. ...
SET amps have a power consumption of a minimal of 8 times the stated stereo power. For example a 10W stereo SET uses a minimal of 80W, typically 100W.
Intentional creation of distortion
Tube sound from transistor amplifiers Some individual characteristics of the tube sound, such as the waveshaping on overdrive, are straightforward to produce in a transistor circuit or digital filter. For more complete simulations, engineers have been successful in developing transistor amplifiers that produce a sound quality very similar to the tube sound. Usually this involves using a circuit topology similar to that used in tube amplifiers. The term Distortion synthesis refers to a group of sound synthesis techniques which modify existing sounds to produce more complex sounds (or timbres), usually by using non-linear circuits or mathematics. ...
An FIR filter In electronics,nirali a digital filter is any electronic filter that works by performing digital mathematical operations on an intermediate form of a signal. ...
In 1982, Tom Scholz, a graduate of MIT and a member of Boston, introduced the Rockman, which used bipolar transistors, but achieved a distorted sound adopted by many well known musicians. Advanced digital signal processing offers the possibility to simulate tube sound. Computer algorithms are currently available that transform digital sound from a CD or other digital source into a distorted digital sound signal. Donald Thomas Tom Scholz (born March 10, 1947), is an American rock musician, songwriter, guitarist, inventor, and electronics engineer. ...
Mapúa Institute of Technology (MIT, MapúaTech or simply Mapúa) is a private, non-sectarian, Filipino tertiary institute located in Intramuros, Manila. ...
Boston is an American rock band that achieved its most notable successes during the 1970s and 1980s. ...
The Rockman is a headphone guitar amplifier. ...
Digital signal processing (DSP) is the study of signals in a digital representation and the processing methods of these signals. ...
This article is about the machine. ...
Flowcharts are often used to represent algorithms. ...
CD may stand for: Compact Disc Canadian Forces Decoration Cash Dispenser (at least used in Japan) CD LPMud Driver Centrum-Demokraterne (Centre Democrats of Denmark) Certificate of Deposit České Dráhy (Czech Railways) Chad (NATO country code) Chalmers Datorförening (computer club of the Chalmers University of Technology) a 1960s...
For other uses, see Digital (disambiguation). ...
Using modern passive components, and modern sources, whether digital or analogue, and wide band loudspeakers, it is possible to have tube amplifiers with the characteristic wide bandwidth and "fast" sound of modern transistor amplifiers, including using push-pull circuits, class AB, and feedback. Some enthusiasts have built amplifiers using transistors and MOSFETs that operate in class A, including single ended, and these often have the "tube sound" [citation needed]. A passive component is an electronic component that does not require a source of energy to perform its intended function. ...
For other uses, see Digital (disambiguation). ...
For the Marty Friedman album, see Loudspeaker (album) An inexpensive low fidelity 3. ...
Tube/transistor "HYBRID" amplifiers Tubes are often used to impart characteristics that many people find audibly pleasant to solid state amplifiers, such as Musical Fidelity's use of Nuvistors, tiny triode tubes, to control large bi-polar transistors in their NuVista 300 power amp. In America, Moscode and Studio Electric use this method, but use MOSFET transistors for power, rather than bi-polar. Pathos, an Italian company, has developed an entire line of hybrid amplifiers. Musical Fidelity is a low volume producer of high-end audio) equipment. ...
The nuvistor is a type of vacuum tube announced by RCA in 1959. ...
To demonstrate one aspect of this effect, one may use a light bulb in the feedback loop of an infinite gain multiple feedback (IGMF) circuit. The slow response of the light bulb's resistance (which varies according to temperature) can thus be used to moderate the sound and attain a tube-like "soft limiting" of the output, though other aspects of "the tube sound" would not be duplicated in this exercise. The light bulb is one of the most significant inventions in the history of the human race, illuminating the darkness of the evening and bringing light indoors at all times in order focus on the task at hand. ...
Conductance can refer to: Electrical conductance, the reciprocal of electrical resistance. ...
For other uses, see Temperature (disambiguation). ...
Tube sound enthusiasts Some enthusiasts[attribution needed] consider that "pure" tube amplifiers should not use anything except tubes as active devices. Others, in contrast, will use tubes for the audio circuit, but will accept the use of semiconductor gain devices in the power supply or as constant current sources. Other schisms concern the use of triodes vs. tetrodes and pentodes, and the use of directly heated tubes vs. indirectly heated tubes. An ideal current source, I, driving a resistor, R, and creating a voltage V A current source is an electrical or electronic device that delivers or absorbs electric current. ...
Simplified diagram of a triode. ...
This article does not cite any references or sources. ...
This article does not cite any references or sources. ...
Many of the explanations relate to the circuit topologies pioneered using tubes, and traditionally associated with them ever since, regardless of whether they are built using tubes today, notably the directly heated single-ended triode amplifier circuit, which operates in class A and often has no external negative feedback; this topology is a classic source of the tube sound. Triodes always have a property called Miller Capacitance which couples the output plate to the input grid, effectively acting as a negative feedback path. Because this feedback path is extremely short, it performs very well. Feedback paths coupled through the secondary of the output transformer, on the other hand, may introduce distortion due to the time lag caused by the transformer. A SET tube audio amplifier. ...
This topic has already been covered in electronic amplifier. ...
This article does not cite any references or sources. ...
See also It has been suggested that Audio quality measurement be merged into this article or section. ...
This article does not cite any references or sources. ...
Since 2000 each year the European Triode Festival (ETF) has been held in various venues in Europe (the first three events were called Aarhus Triode Festival aka ATF. The ETF focuses on do-it-yourself audio valve amplifiers using triode vacuum tubes, and brings together some 100 high end vacuum...
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