None of latest stereo systems would be achievable lacking the help of today's power amps which attempt to satisfy higher and higher requirements concerning power and music fidelity. There is a big quantity of amplifier designs and types. All of these differ regarding performance. I will explain 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 amps is best for your application. Furthermore, after understanding this guide you should be able to comprehend the amp specs which producers publish.
Simply put, the function of an audio amplifier is to translate a low-power music signal into a high-power audio signal. The high-power signal is great enough to drive a speaker sufficiently loud. Determined by the kind of amp, one of several kinds of elements are used in order to amplify the signal like tubes in addition to transistors.
Tube amplifiers used to be popular a few decades ago. A tube is able to control the current flow in accordance to a control voltage that is attached to the tube. Tubes, on the other hand, are nonlinear in their behavior and are going to introduce a fairly large amount of higher harmonics or distortion. Though, this characteristic of tube amplifiers still makes these popular. Many people describe tube amplifiers as having a warm sound as opposed to the cold sound of solid state amplifiers.
Moreover, tube amplifiers have quite low power efficiency and thereby dissipate much power as heat. Furthermore, tubes are fairly expensive to manufacture. Thus tube amps have by and large been replaced by solid-state amplifiers which I will glance at next.
In order to improve on the small efficiency of class-A amplifiers, class-AB amps employ a series of transistors which each amplify a distinct area, each of which being more efficient than class-A amplifiers. The higher efficiency of class-AB amplifiers also has two further advantages. First of all, the required amount of heat sinking is reduced. As a result class-AB amps can be made lighter and smaller. For that reason, class-AB amps can be made cheaper than class-A amps. When the signal transitions between the 2 distinct regions, however, a certain amount of distortion is being produced, thereby class-AB amplifiers will not achieve the same audio fidelity as class-A amplifiers.
Class-D amplifiers are able to achieve power efficiencies above 90% by employing a switching transistor that is continuously being switched on and off and therefore the transistor itself does not dissipate any heat. The switching transistor, that is being controlled by a pulse-width modulator generates a high-frequency switching component which has to be removed from the amplified signal by utilizing a lowpass filter. Both the pulse-width modulator and the transistor have non-linearities which result in class-D amps having larger audio distortion than other kinds of amplifiers.
Class-D amplifiers are able to attain power efficiencies higher than 90% by utilizing a switching transistor that is continuously being switched on and off and as a result the transistor itself does not dissipate any heat. The on-off switching times of the transistor are being controlled by a pulse-with modulator (PWM). Usual switching frequencies are between 300 kHz and 1 MHz. This high-frequency switching signal has to be removed from the amplified signal by a lowpass filter. Usually a straightforward first-order lowpass is being used. Both the pulse-width modulator and the transistor have non-linearities that result in class-D amplifiers having bigger audio distortion than other types of amplifiers. Modern amps incorporate internal audio feedback in order to minimize the amount of music distortion. A well-known architecture which uses this sort of feedback is called "class-T". Class-T amplifiers or "t amps" attain audio distortion which compares with the audio distortion of class-A amps while at the same time having the power efficiency of class-D amps. Consequently t amplifiers can be manufactured extremely small and yet attain high audio fidelity.
Simply put, the function of an audio amplifier is to translate a low-power music signal into a high-power audio signal. The high-power signal is great enough to drive a speaker sufficiently loud. Determined by the kind of amp, one of several kinds of elements are used in order to amplify the signal like tubes in addition to transistors.
Tube amplifiers used to be popular a few decades ago. A tube is able to control the current flow in accordance to a control voltage that is attached to the tube. Tubes, on the other hand, are nonlinear in their behavior and are going to introduce a fairly large amount of higher harmonics or distortion. Though, this characteristic of tube amplifiers still makes these popular. Many people describe tube amplifiers as having a warm sound as opposed to the cold sound of solid state amplifiers.
Moreover, tube amplifiers have quite low power efficiency and thereby dissipate much power as heat. Furthermore, tubes are fairly expensive to manufacture. Thus tube amps have by and large been replaced by solid-state amplifiers which I will glance at next.
In order to improve on the small efficiency of class-A amplifiers, class-AB amps employ a series of transistors which each amplify a distinct area, each of which being more efficient than class-A amplifiers. The higher efficiency of class-AB amplifiers also has two further advantages. First of all, the required amount of heat sinking is reduced. As a result class-AB amps can be made lighter and smaller. For that reason, class-AB amps can be made cheaper than class-A amps. When the signal transitions between the 2 distinct regions, however, a certain amount of distortion is being produced, thereby class-AB amplifiers will not achieve the same audio fidelity as class-A amplifiers.
Class-D amplifiers are able to achieve power efficiencies above 90% by employing a switching transistor that is continuously being switched on and off and therefore the transistor itself does not dissipate any heat. The switching transistor, that is being controlled by a pulse-width modulator generates a high-frequency switching component which has to be removed from the amplified signal by utilizing a lowpass filter. Both the pulse-width modulator and the transistor have non-linearities which result in class-D amps having larger audio distortion than other kinds of amplifiers.
Class-D amplifiers are able to attain power efficiencies higher than 90% by utilizing a switching transistor that is continuously being switched on and off and as a result the transistor itself does not dissipate any heat. The on-off switching times of the transistor are being controlled by a pulse-with modulator (PWM). Usual switching frequencies are between 300 kHz and 1 MHz. This high-frequency switching signal has to be removed from the amplified signal by a lowpass filter. Usually a straightforward first-order lowpass is being used. Both the pulse-width modulator and the transistor have non-linearities that result in class-D amplifiers having bigger audio distortion than other types of amplifiers. Modern amps incorporate internal audio feedback in order to minimize the amount of music distortion. A well-known architecture which uses this sort of feedback is called "class-T". Class-T amplifiers or "t amps" attain audio distortion which compares with the audio distortion of class-A amps while at the same time having the power efficiency of class-D amps. Consequently t amplifiers can be manufactured extremely small and yet attain high audio fidelity.
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