None of latest audio products would be possible without the aid of today's stereo amplifiers that strive to satisfy higher and higher requirements concerning power and audio fidelity. It is challenging to pick an amplifier given the huge range of products and concepts. I will describe some of the most popular amp designs such as "tube amplifiers", "linear amps", "class-AB" and "class-D" in addition to "class-T amps" to help you comprehend some of the terms commonly utilized by amp producers. This article should also help you figure out which topology is best for your particular application.
Tube amplifiers used to be common a number of decades ago. A tube is able to control the current flow according to a control voltage which is attached to the tube. Sadly, tube amplifiers have a rather high level of distortion. Technically speaking, tube amps are going to introduce higher harmonics into the signal. Though, this characteristic of tube amplifiers still makes these popular. A lot of people describe tube amps as having a warm sound versus the cold sound of solid state amplifiers.
A couple of decades ago, the most common type of audio amp were tube amplifiers. Tube amps utilize a tube as the amplifying element. The current flow through the tube is controlled by a low-level control signal. Thereby the low-level audio is converted into a high-level signal. Sadly, tube amplifiers have a reasonably high amount of distortion. Technically speaking, tube amps will introduce higher harmonics into the signal. However, this characteristic of tube amplifiers still makes these popular. A lot of people describe tube amplifiers as having a warm sound versus the cold sound of solid state amplifiers. One disadvantage of tube amps is their low power efficiency. In other words, the majority of the energy consumed by the amp is wasted as heat instead of being transformed into music. Consequently tube amplifiers will run hot and require enough cooling. Tube amplifiers, though, a fairly expensive to make and consequently tube amps have by and large been replaced with amps utilizing transistor elements which are less expensive to produce.
Solid state amps replace the tube with semiconductor elements, usually bipolar transistors or FETs. The first type of solid-state amplifiers is often known as class-A amplifiers. The working principle of class-A amplifiers is very similar to that of tube amplifiers. The primary difference is that a transistor is being used instead of the tube for amplifying the music signal. The amplified high-level signal is sometimes fed back to reduce harmonic distortion. In terms of harmonic distortion, class-A amps rank highest amid all kinds of power amps. These amps also regularly exhibit quite low noise. As such class-A amplifiers are ideal for quite demanding applications in which low distortion and low noise are vital. Class-A amps, however, waste most of the energy as heat. For that reason they generally have big heat sinks and are quite bulky.
Solid state amps replace the tube with semiconductor elements, typically bipolar transistors or FETs. The first kind of solid-state amplifiers is called class-A amps. The working principle of class-A amps is quite similar to that of tube amps. The key difference is that a transistor is being utilized rather than the tube for amplifying the music signal. The amplified high-level signal is at times fed back in order to lessen harmonic distortion. Class-A amps have the smallest distortion and generally also the lowest amount of noise of any amplifier architecture. If you require ultra-low distortion then you should take a closer look at class-A models. The major drawback is that similar to tube amps class A amps have very low efficiency. As a result these amplifiers require large heat sinks in order to radiate the wasted energy and are usually fairly large.
To further improve the audio efficiency, "class-D" amplifiers employ a switching stage which is continually switched between 2 states: on or off. None of these two states dissipates energy within the transistor. As a result, class-D amplifiers frequently are able to attain power efficiencies higher than 90%. The switching transistor is being controlled by a pulse-width modulator. The switched large-level signal has to be lowpass filtered to remove the switching signal and recover the music signal. Both the pulse-width modulator and the transistor have non-linearities that result in class-D amps exhibiting larger music distortion than other types of amplifiers.
Modern amplifiers include internal audio feedback in order to reduce the level of audio distortion. "Class-T" amplifiers (also referred to as "t-amplifier") utilize this type of feedback method and thus can be manufactured extremely small whilst achieving low audio distortion.
Tube amplifiers used to be common a number of decades ago. A tube is able to control the current flow according to a control voltage which is attached to the tube. Sadly, tube amplifiers have a rather high level of distortion. Technically speaking, tube amps are going to introduce higher harmonics into the signal. Though, this characteristic of tube amplifiers still makes these popular. A lot of people describe tube amps as having a warm sound versus the cold sound of solid state amplifiers.
A couple of decades ago, the most common type of audio amp were tube amplifiers. Tube amps utilize a tube as the amplifying element. The current flow through the tube is controlled by a low-level control signal. Thereby the low-level audio is converted into a high-level signal. Sadly, tube amplifiers have a reasonably high amount of distortion. Technically speaking, tube amps will introduce higher harmonics into the signal. However, this characteristic of tube amplifiers still makes these popular. A lot of people describe tube amplifiers as having a warm sound versus the cold sound of solid state amplifiers. One disadvantage of tube amps is their low power efficiency. In other words, the majority of the energy consumed by the amp is wasted as heat instead of being transformed into music. Consequently tube amplifiers will run hot and require enough cooling. Tube amplifiers, though, a fairly expensive to make and consequently tube amps have by and large been replaced with amps utilizing transistor elements which are less expensive to produce.
Solid state amps replace the tube with semiconductor elements, usually bipolar transistors or FETs. The first type of solid-state amplifiers is often known as class-A amplifiers. The working principle of class-A amplifiers is very similar to that of tube amplifiers. The primary difference is that a transistor is being used instead of the tube for amplifying the music signal. The amplified high-level signal is sometimes fed back to reduce harmonic distortion. In terms of harmonic distortion, class-A amps rank highest amid all kinds of power amps. These amps also regularly exhibit quite low noise. As such class-A amplifiers are ideal for quite demanding applications in which low distortion and low noise are vital. Class-A amps, however, waste most of the energy as heat. For that reason they generally have big heat sinks and are quite bulky.
Solid state amps replace the tube with semiconductor elements, typically bipolar transistors or FETs. The first kind of solid-state amplifiers is called class-A amps. The working principle of class-A amps is quite similar to that of tube amps. The key difference is that a transistor is being utilized rather than the tube for amplifying the music signal. The amplified high-level signal is at times fed back in order to lessen harmonic distortion. Class-A amps have the smallest distortion and generally also the lowest amount of noise of any amplifier architecture. If you require ultra-low distortion then you should take a closer look at class-A models. The major drawback is that similar to tube amps class A amps have very low efficiency. As a result these amplifiers require large heat sinks in order to radiate the wasted energy and are usually fairly large.
To further improve the audio efficiency, "class-D" amplifiers employ a switching stage which is continually switched between 2 states: on or off. None of these two states dissipates energy within the transistor. As a result, class-D amplifiers frequently are able to attain power efficiencies higher than 90%. The switching transistor is being controlled by a pulse-width modulator. The switched large-level signal has to be lowpass filtered to remove the switching signal and recover the music signal. Both the pulse-width modulator and the transistor have non-linearities that result in class-D amps exhibiting larger music distortion than other types of amplifiers.
Modern amplifiers include internal audio feedback in order to reduce the level of audio distortion. "Class-T" amplifiers (also referred to as "t-amplifier") utilize this type of feedback method and thus can be manufactured extremely small whilst achieving low audio distortion.
Aucun commentaire:
Enregistrer un commentaire