AudioBahn Amplifiers can be implemented using transistors of various types, or vacuum tubes (valves).
Transistor
A transistor is a semiconductor device that uses a small amount of voltage or electrical current to control a larger change in voltage or current. The transistor is the fundamental building block of the circuitry that governs the operation of computers, cellular phones, and all other modern electronics.
Because of its fast response and accuracy, the transistor may be used in a wide variety of digital and analog functions, including amplification, switching, voltage regulation, signal modulation, and oscillators. Transistors may be packaged individually or as part of an integrated circuit chip, which may hold thousands of transistors in a very small area.
Vacuum Tubes
In electronics, a vacuum tube or (outside North America) thermionic valve or just valve, is a device generally used to amplify, switch or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. For most purposes, the vacuum tube has been replaced by the much smaller and less expensive transistor, either as a discrete device or in an integrated circuit. However, tubes are still used in several applications such as in audio systems and high power RF transmitters. Cathode ray tubes are used as the display device in television sets and computer monitors, and magnetrons are the source of microwaves in microwave ovens.
The vacuum tube is a voltage-controlled device, which means that the relationship between the input and output circuits is determined by a transconductance function. The solid-state device most closely analogous to the vacuum tube is the JFET, although the vacuum tube typically operates at far higher voltage (and power) levels than the JFET.
Monday, January 8, 2007
AudioBahn Electronic Amplifier
AudioBahn Electronic Amplifier
An electronic amplifier is a device for increasing the power of a signal. It does this by taking power from a power supply and controlling the output to match the input signal shape but with a larger amplitude. An idealized amplifier can be said to be "a piece of wire with gain", as the output is an exact replica of the input, but larger.
Classification of amplifier stages and systems
Different designs of amplifiers are used for different types of applications and signals. We can broadly divide amplifiers into three categories:
Small signal amplifiers,
Low frequency power amplifiers and
Radio frequency RF power amplifiers.
Each of these calls for a slightly different design approach, mainly because of the physical limitations of the components used to implement the amplifier, and the efficiencies that can be realised.
There are many alternative classifications that address different aspects of amplifier designs, and they all have some effect on the design parameters and objectives of the circuit. Amplifier design is always a compromise of numerous factors, such as cost, amount of power consumed, devices that have real-world imperfections, and the need to match the amplifier to the input signal as well as the output load.
Classification of amplifier stages by common terminal
One set of these classifications include terms referring to “common terminal” connections, where the design is described by the terminal of the active device that is tied closest to ground. Examples include terms such as common emitter, common plate, or common drain, and these names also reflect the type of active device used to amplify the signal. For instance, common emitter refers to an amplifier with a bipolar transistor as the active device, while common plate would be for a vacuum tube amp, while a common drain amp would signify the use of MOSFET or JFET devices. Designs exist for almost any terminal of any active device to be held to ground in an amplifier, for different reasons that are reflected in each use. See also: common collector, common base.
Inverting or non-inverting
Another way to classify amps is the phase relationship of the input signal to the output signal. An inverting amplifier produces an output that is 180 degrees out of phase of the input signal, or a mirror image of it if viewed on an oscilloscope. A non-inverting amplifier maintains equal phase relationship between the input and output waveforms. An emitter follower is a type of this amplifier, indicating that the signal at the emitter of a transistor is following (matching phases) with the input signal.
This description can apply to a single stage or a complete system.
Function
Other amps may be classified by their function or output characteristics. These functional descriptions usually apply to complete amplifier systems or sub-systems and rarely to individual stages.
A servo amp indicates an integrated feedback loop to actively control the output at some desired level. A DC servo indicates use at frequencies down to DC levels, where the rapid fluctuations of an audio or RF signal do not occur. These are often used in mechanical actuators, or devices such as DC motors that must maintain a constant speed or torque. An AC servo amp can do this for some ac motors.
A linear amp denotes that it has a precise amplification factor over a wide range of frequencies, and is often used to boost signals for relay in communications systems. A non-linear amp is made to amplify only a specific narrow or tuned frequency, to the exclusion of all other frequencies.
A RF amp refers to an amp designed for use in the radio frequency range of the electromagnetic spectrum, and is often used to increase the sensitivity of a receiver or the output power of a transmitter.
An audio amp is designed for use in reproducing audio frequencies, with special considerations made for driving speakers. These often have multiple amps grouped together as separate or bridgeable channels to accommodate different audio reproduction requirements.
A special type of low power amp with almost ideal characteristics is used in instruments and for signal processing, among many other varied uses. These are known as operational amplifiers, or op-amps. This is because this type of amplifier is used in circuits that perform mathematical algorithmic functions, or "operations" on input signals to obtain specific types of output signals.
For More Information, Please Visit: http://en.wikipedia.org/wiki/Electronic_amplifier
An electronic amplifier is a device for increasing the power of a signal. It does this by taking power from a power supply and controlling the output to match the input signal shape but with a larger amplitude. An idealized amplifier can be said to be "a piece of wire with gain", as the output is an exact replica of the input, but larger.
Classification of amplifier stages and systems
Different designs of amplifiers are used for different types of applications and signals. We can broadly divide amplifiers into three categories:
Small signal amplifiers,
Low frequency power amplifiers and
Radio frequency RF power amplifiers.
Each of these calls for a slightly different design approach, mainly because of the physical limitations of the components used to implement the amplifier, and the efficiencies that can be realised.
There are many alternative classifications that address different aspects of amplifier designs, and they all have some effect on the design parameters and objectives of the circuit. Amplifier design is always a compromise of numerous factors, such as cost, amount of power consumed, devices that have real-world imperfections, and the need to match the amplifier to the input signal as well as the output load.
Classification of amplifier stages by common terminal
One set of these classifications include terms referring to “common terminal” connections, where the design is described by the terminal of the active device that is tied closest to ground. Examples include terms such as common emitter, common plate, or common drain, and these names also reflect the type of active device used to amplify the signal. For instance, common emitter refers to an amplifier with a bipolar transistor as the active device, while common plate would be for a vacuum tube amp, while a common drain amp would signify the use of MOSFET or JFET devices. Designs exist for almost any terminal of any active device to be held to ground in an amplifier, for different reasons that are reflected in each use. See also: common collector, common base.
Inverting or non-inverting
Another way to classify amps is the phase relationship of the input signal to the output signal. An inverting amplifier produces an output that is 180 degrees out of phase of the input signal, or a mirror image of it if viewed on an oscilloscope. A non-inverting amplifier maintains equal phase relationship between the input and output waveforms. An emitter follower is a type of this amplifier, indicating that the signal at the emitter of a transistor is following (matching phases) with the input signal.
This description can apply to a single stage or a complete system.
Function
Other amps may be classified by their function or output characteristics. These functional descriptions usually apply to complete amplifier systems or sub-systems and rarely to individual stages.
A servo amp indicates an integrated feedback loop to actively control the output at some desired level. A DC servo indicates use at frequencies down to DC levels, where the rapid fluctuations of an audio or RF signal do not occur. These are often used in mechanical actuators, or devices such as DC motors that must maintain a constant speed or torque. An AC servo amp can do this for some ac motors.
A linear amp denotes that it has a precise amplification factor over a wide range of frequencies, and is often used to boost signals for relay in communications systems. A non-linear amp is made to amplify only a specific narrow or tuned frequency, to the exclusion of all other frequencies.
A RF amp refers to an amp designed for use in the radio frequency range of the electromagnetic spectrum, and is often used to increase the sensitivity of a receiver or the output power of a transmitter.
An audio amp is designed for use in reproducing audio frequencies, with special considerations made for driving speakers. These often have multiple amps grouped together as separate or bridgeable channels to accommodate different audio reproduction requirements.
A special type of low power amp with almost ideal characteristics is used in instruments and for signal processing, among many other varied uses. These are known as operational amplifiers, or op-amps. This is because this type of amplifier is used in circuits that perform mathematical algorithmic functions, or "operations" on input signals to obtain specific types of output signals.
For More Information, Please Visit: http://en.wikipedia.org/wiki/Electronic_amplifier
AudioBahn Amplifiers
Amplifiers
Generally, an amplifier is any device that uses a small amount of energy to control a larger amount of energy. In popular use, the term today usually refers to an electronic amplifier, often as in audio applications. The relationship of the input to the output of an amplifier — usually expressed as a function of the input frequency — is called the transfer function of the amplifier, and the magnitude of the transfer function is termed the gain.
Amplifier Classes
Amplifier classes
Amplifiers are commonly classified by the conduction angle (sometimes known as 'angle of flow') of the input signal through the amplifying device; see electronic amplifier.
Class A
Where efficiency is not a consideration, most small signal linear amplifiers are designed as Class A, which means that the output devices are always in the conduction region. Class A amplifiers are typically more linear and less complex than other types, but are very inefficient. This type of amplifier is most commonly used in small-signal stages or for low-power applications (such as driving headphones).
Class B
In Class B, there are two output devices (or sets of output devices), each of which conducts alternately for exactly 180 deg (or half cycle) of the input signal.
Class AB
Class AB amplifiers are a compromise between Class A and B, which improves small signal output linearity; conduction angles vary from 180 degrees upwards, selected by the amplifier designer. Usually found in low frequency amplifiers (such as audio and hi-fi) owing to their relatively high efficiency, or other designs where both linearity and efficiency are important (cell phones, cell towers, TV transmitters).
Class C
Popular for high power RF amplifiers, Class C is defined by conduction for less than 180° of the input signal. Linearity is not good, but this is of no significance for single frequency power amplifiers. The signal is restored to near sinusoidal shape by a tuned circuit, and efficiency is much higher than A, AB, or B classes of amplification.
Class D
Class D amplifiers use switching to achieve a very high power efficiency (more than 90% in modern designs). By allowing each output device to be either fully on or off, losses are minimized. A simple approach such as pulse-width modulation is sometimes still used; however, high-performance switching amplifiers use digital techniques, such as sigma-delta modulation, to achieve superior performance. Formerly used only for subwoofers due to their limited bandwidth and relatively high distortion, the evolution of semiconductor devices has made possible the development of high fidelity, full audio range Class D amplifiers, with S/N and distortion levels similar to their linear counterparts.
Other classes
There are several other amplifier classes, although they are mainly variations of the previous classes. For example, Class H and Class I amplifiers are marked by variation of the supply rails (in discrete steps or in a continuous fashion, respectively) following the input signal. Wasted heat on the output devices can be reduced as excess voltage is kept to a minimum. The amplifier that is fed with these rails itself can be of any class. These kinds of amplifiers are more complex, and are mainly used for specialized applications, such as very high-power units. Also, Class E and Class F amplifiers are commonly described in literature for radio frequencies applications where efficiency of the traditional classes deviate substantially from their ideal values. These classes use harmonic tuning of their output networks to achieve higher efficiency and can be considered a subset of Class C due to their conduction angle characteristics.
For More Information, Please Visit: http://en.wikipedia.org/wiki/Amplifier
Generally, an amplifier is any device that uses a small amount of energy to control a larger amount of energy. In popular use, the term today usually refers to an electronic amplifier, often as in audio applications. The relationship of the input to the output of an amplifier — usually expressed as a function of the input frequency — is called the transfer function of the amplifier, and the magnitude of the transfer function is termed the gain.
Amplifier Classes
Amplifier classes
Amplifiers are commonly classified by the conduction angle (sometimes known as 'angle of flow') of the input signal through the amplifying device; see electronic amplifier.
Class A
Where efficiency is not a consideration, most small signal linear amplifiers are designed as Class A, which means that the output devices are always in the conduction region. Class A amplifiers are typically more linear and less complex than other types, but are very inefficient. This type of amplifier is most commonly used in small-signal stages or for low-power applications (such as driving headphones).
Class B
In Class B, there are two output devices (or sets of output devices), each of which conducts alternately for exactly 180 deg (or half cycle) of the input signal.
Class AB
Class AB amplifiers are a compromise between Class A and B, which improves small signal output linearity; conduction angles vary from 180 degrees upwards, selected by the amplifier designer. Usually found in low frequency amplifiers (such as audio and hi-fi) owing to their relatively high efficiency, or other designs where both linearity and efficiency are important (cell phones, cell towers, TV transmitters).
Class C
Popular for high power RF amplifiers, Class C is defined by conduction for less than 180° of the input signal. Linearity is not good, but this is of no significance for single frequency power amplifiers. The signal is restored to near sinusoidal shape by a tuned circuit, and efficiency is much higher than A, AB, or B classes of amplification.
Class D
Class D amplifiers use switching to achieve a very high power efficiency (more than 90% in modern designs). By allowing each output device to be either fully on or off, losses are minimized. A simple approach such as pulse-width modulation is sometimes still used; however, high-performance switching amplifiers use digital techniques, such as sigma-delta modulation, to achieve superior performance. Formerly used only for subwoofers due to their limited bandwidth and relatively high distortion, the evolution of semiconductor devices has made possible the development of high fidelity, full audio range Class D amplifiers, with S/N and distortion levels similar to their linear counterparts.
Other classes
There are several other amplifier classes, although they are mainly variations of the previous classes. For example, Class H and Class I amplifiers are marked by variation of the supply rails (in discrete steps or in a continuous fashion, respectively) following the input signal. Wasted heat on the output devices can be reduced as excess voltage is kept to a minimum. The amplifier that is fed with these rails itself can be of any class. These kinds of amplifiers are more complex, and are mainly used for specialized applications, such as very high-power units. Also, Class E and Class F amplifiers are commonly described in literature for radio frequencies applications where efficiency of the traditional classes deviate substantially from their ideal values. These classes use harmonic tuning of their output networks to achieve higher efficiency and can be considered a subset of Class C due to their conduction angle characteristics.
For More Information, Please Visit: http://en.wikipedia.org/wiki/Amplifier
AudioBahn Audio
AudiBahn Audio
Audiobahn's force has been climaxing at a swift rate since the company's initiation in the late 90’s. AudioBahn’s imaginative amplifier designs, exceptional signal processors, and the outrageously fan-favorite flame collection continues to leave their competition trailing behind.
Audiobahn’s amplifiers and subwoofers integrate all of the characteristics that you would require from a tremendously powerful corporation: Performance, quality, and design - including more pioneering characteristics than you can think of! Audiobahn’s line of products have always and will continuously be the choice of the automotive fans and experts, producing the clarified and clearest music that you can ask for.
For More Information, Please Visit: http://www.audiobahn.com/Audiobahn06/pages/2006.html
Audiobahn's force has been climaxing at a swift rate since the company's initiation in the late 90’s. AudioBahn’s imaginative amplifier designs, exceptional signal processors, and the outrageously fan-favorite flame collection continues to leave their competition trailing behind.
Audiobahn’s amplifiers and subwoofers integrate all of the characteristics that you would require from a tremendously powerful corporation: Performance, quality, and design - including more pioneering characteristics than you can think of! Audiobahn’s line of products have always and will continuously be the choice of the automotive fans and experts, producing the clarified and clearest music that you can ask for.
For More Information, Please Visit: http://www.audiobahn.com/Audiobahn06/pages/2006.html
Subscribe to:
Posts (Atom)