What are the audio amplifier classes? What are their features and differences
A sound amplifier is a complex device that works most often on the basis of transistors and is capable of amplifying electrical vibrations at low frequencies perceived by the human ear. Its main task is to adjust the sound signal in order to obtain the necessary power, and transmit it to various sound-reproducing devices. It is thanks to the use of these devices that you can extend the capabilities of any audio systems and achieve a more powerful and rich sound.
Features of using audio amplifiers
The amplifier is the final element when creating a sound reinforcement system. These devices can be made in the form of independent blocks, with a separate control panel, or they can have internal elements placed inside the hybrid microcircuit. They are found in almost every instrument that reproduces sound signals in the radio, speakers, computers, smartphones, headphones, and even musical toys.
All amplifiers can be divided into 2 main groups: household and professional.
Household devices are those devices that can provide only a small level of amplification with little sound distortion. They are usually used in home audio systems, where it is more important to achieve the maximum sound quality rather than high volume.
Professional amplifiers are more powerful systems that are commonly used for recording studio recordings, at concerts, when dubbing various events, etc. The main advantage of this type of sound equipment is high efficiency, high power and noticeable sound amplification.
Of course, amplifiers are also used in car audio systems, they are necessary for the formation of an optimal acoustics sound in a car interior. It is very important when choosing an amplifier for a car to pay attention to the main technical parameters of the device: power, private range, resistance, number of channels and others. One of these important parameters is also the class of the amplifier.
Sound Amplifier Classifications
These devices differ in principle and mode of operation, so they are divided into several main classes. Moreover, some 20 years ago it was possible to find only 2 variants of sound amplifiers: “A” and “AB”. Today, a variety of varieties are available in several main classes: "A", "AV", "B", "C", "D" and others. This diversity is due to the use of the latest technology in the manufacture of semiconductor elements. They gave the opportunity to increase the quality of sound reproduction, minimize the size and significantly reduce the cost of amplifiers. So let's consider what classes there are and their main features and differences.
Amplifiers of this class are characterized by low efficiency, but a “pure” signal. This class is considered to be audiophile, since such devices provide minimal indicators of sound distortion. Their efficiency is about 20-30%. They are quite expensive at low power, so in automobile audio systems such devices are installed quite rarely. They can sometimes be found in expensive audio systems.
But they also have a significant drawback-high quiescent current. This value characterizes the current that passes through the transistors, even if there is no input signal. This provokes the heating of the amplifiers, with most of the energy from the power supply is converted into heat, which leads to low efficiency.
In audio amplifiers of this class, the efficiency is significantly higher compared to the previous one-about two times. Their efficiency is about 70%. But their output signal is much more distorted. It is believed that they give a sound of low quality, many experts call it "dry." That is why this type of amplifier is considered unsuitable for car audio systems and is almost never installed in cars.
This, as the name implies, is a combined version-the average between the first two types. It is characteristic that amplifiers of this class with a high level signal can work as class “B” amplifiers, and with a low level signal-as class “A” amplifiers. That is, this class combines the pure sound characteristic of type A devices and type B efficiency. This makes them the most common car amplifiers at the moment.
If we talk about performance, their efficiency is about 60%. This is sufficient to obtain high quality sound transmission and ensure clear sound even at high volume. Class AB amplifiers are often used in the formation of high-end audio systems.
This class of amplifiers appeared relatively recently. Devices of this type use digital audio signal processing and special switching power supplies. The advanced design and the most advanced sound processing technologies have made it possible to get a powerful sound amplifier in a compact size and low weight.
In a classic amplifier, transistors output a continuous signal at the output. At the same time, rather large power dissipation is noted in them at the linear outputs. But in class D devices, power is almost not dissipated, and therefore is not lost. This property extends the use of amplifiers of this type. This is explained by the fact that low power dissipation contributes to the fact that the circuit almost does not heat up, and also makes it possible to save space on the board. All this not only reduces the final cost of the product, but increases the battery life. It is also worth noting that they can amplify a digital signal without converting it to analog. This technology is used if the audio signal is already supplied to the device in digital form.
One of the main advantages of Class D audio amplifiers is high efficiency-from 85 to 95% without loss of quality. This indicator is achieved due to the fact that the amplitude of the pulses is almost equal to the indicator of the supply voltage, therefore, at the output transistors, the power loss is very small. At the same time, interference and distortion in the transmission of sound is also relatively small. Amplifiers of this class are a great option for installation in a car.
As you can see, the class of a sound amplifier largely determines its performance and the quality of sound reproduction. And it must be taken into account when choosing a device to get the best result in the end, after connecting all the sound equipment. If you want to buy a car audio amplifier in Kiev, Odessa, Kharkov, the shop 130.com.ua offers a very large selection of models from leading manufacturers of professional acoustic equipment.