None of latest music systems would be doable without the help of today's power amps that strive to satisfy higher and higher requirements regarding power and audio fidelity. There is a large quantity of amplifier styles and types. All of these differ in terms of performance. I will describe a few of the most common amp terms such as "class-A", "class-D" and "t amps" to help you figure out which of these amplifiers is ideal for your application. Additionally, after reading this essay you should be able to comprehend the amp specs that makers issue.
Simply put, the use of an audio amplifier is to convert a low-power music signal into a high-power music signal. The high-power signal is large enough to drive a loudspeaker sufficiently loud. Depending on the type of amplifier, one of several kinds of elements are used to amplify the signal such as tubes and transistors.
Tube amps used to be common a couple of decades ago. A tube is able to control the current flow in accordance to a control voltage that is attached to the tube. Sadly, tube amplifiers have a reasonably high amount of distortion. Technically speaking, tube amplifiers will introduce higher harmonics into the signal. However, this characteristic of tube amps still makes these popular. A lot of people describe tube amps as having a warm sound versus the cold sound of solid state amps. One more disadvantage of tube amplifiers, though, is the small power efficiency. The bulk of power which tube amplifiers use up is being dissipated as heat and only a fraction is being converted into audio power. Yet another downside is the high price tag of tubes. This has put tube amplifiers out of the ballpark for the majority of consumer devices. Because of this, the majority of audio products these days uses solid state amps. I am going to explain solid state amplifiers in the next paragraphs.
The first generation versions of solid state amps are generally known as "Class-A" amps. Solid-state amplifiers use a semiconductor rather than a tube to amplify the signal. Usually bipolar transistors or FETs are being utilized. In class-A amps a transistor controls the current flow according to a small-level signal. Several amps utilize a feedback mechanism to reduce the harmonic distortion. Regarding harmonic distortion, class-A amplifiers rank highest amid all kinds of music amplifiers. These amplifiers also typically exhibit quite low noise. As such class-A amps are ideal for very demanding applications in which low distortion and low noise are essential. However, similar to tube amps, class-A amps have extremely low power efficiency and most of the energy is wasted.
In order to improve on the low efficiency of class-A amplifiers, class-AB amps make use of a number of transistors which each amplify a distinct area, each of which being more efficient than class-A amplifiers. Because of the larger efficiency, class-AB amps do not require the same number of heat sinks as class-A amps. As a result they can be made lighter and less costly. Class-AB amps have a drawback though. Every time the amplified signal transitions from one region to the other, there will be certain distortion created. In other words the transition between those two areas is non-linear in nature. Consequently class-AB amps lack audio fidelity compared with class-A amps.
By employing a number of transistors, class-AB amplifiers improve on the low power efficiency of class-A amps. The working region is split into 2 separate regions. These two regions are handled by separate transistors. Each of these transistors works more efficiently than the single transistor in a class-A amplifier. As such, class-AB amps are usually smaller than class-A amps. Though, this topology adds some non-linearity or distortion in the region where the signal switches between those areas. As such class-AB amps generally have larger distortion than class-A amps.
More recent audio amplifiers include some kind of mechanism in order to reduce distortion. One method is to feed back the amplified audio signal to the input of the amp in order to compare with the original signal. The difference signal is then used in order to correct the switching stage and compensate for the nonlinearity. One type of audio amps that makes use of this type of feedback is known as "class-T" or "t amp". Class-T amplifiers feed back the high-level switching signal to the audio signal processor for comparison. These amps have low music distortion and can be manufactured very small.
Simply put, the use of an audio amplifier is to convert a low-power music signal into a high-power music signal. The high-power signal is large enough to drive a loudspeaker sufficiently loud. Depending on the type of amplifier, one of several kinds of elements are used to amplify the signal such as tubes and transistors.
Tube amps used to be common a couple of decades ago. A tube is able to control the current flow in accordance to a control voltage that is attached to the tube. Sadly, tube amplifiers have a reasonably high amount of distortion. Technically speaking, tube amplifiers will introduce higher harmonics into the signal. However, this characteristic of tube amps still makes these popular. A lot of people describe tube amps as having a warm sound versus the cold sound of solid state amps. One more disadvantage of tube amplifiers, though, is the small power efficiency. The bulk of power which tube amplifiers use up is being dissipated as heat and only a fraction is being converted into audio power. Yet another downside is the high price tag of tubes. This has put tube amplifiers out of the ballpark for the majority of consumer devices. Because of this, the majority of audio products these days uses solid state amps. I am going to explain solid state amplifiers in the next paragraphs.
The first generation versions of solid state amps are generally known as "Class-A" amps. Solid-state amplifiers use a semiconductor rather than a tube to amplify the signal. Usually bipolar transistors or FETs are being utilized. In class-A amps a transistor controls the current flow according to a small-level signal. Several amps utilize a feedback mechanism to reduce the harmonic distortion. Regarding harmonic distortion, class-A amplifiers rank highest amid all kinds of music amplifiers. These amplifiers also typically exhibit quite low noise. As such class-A amps are ideal for very demanding applications in which low distortion and low noise are essential. However, similar to tube amps, class-A amps have extremely low power efficiency and most of the energy is wasted.
In order to improve on the low efficiency of class-A amplifiers, class-AB amps make use of a number of transistors which each amplify a distinct area, each of which being more efficient than class-A amplifiers. Because of the larger efficiency, class-AB amps do not require the same number of heat sinks as class-A amps. As a result they can be made lighter and less costly. Class-AB amps have a drawback though. Every time the amplified signal transitions from one region to the other, there will be certain distortion created. In other words the transition between those two areas is non-linear in nature. Consequently class-AB amps lack audio fidelity compared with class-A amps.
By employing a number of transistors, class-AB amplifiers improve on the low power efficiency of class-A amps. The working region is split into 2 separate regions. These two regions are handled by separate transistors. Each of these transistors works more efficiently than the single transistor in a class-A amplifier. As such, class-AB amps are usually smaller than class-A amps. Though, this topology adds some non-linearity or distortion in the region where the signal switches between those areas. As such class-AB amps generally have larger distortion than class-A amps.
More recent audio amplifiers include some kind of mechanism in order to reduce distortion. One method is to feed back the amplified audio signal to the input of the amp in order to compare with the original signal. The difference signal is then used in order to correct the switching stage and compensate for the nonlinearity. One type of audio amps that makes use of this type of feedback is known as "class-T" or "t amp". Class-T amplifiers feed back the high-level switching signal to the audio signal processor for comparison. These amps have low music distortion and can be manufactured very small.