The function of power amplifier is to amplify weak signals-CD, DVD, computer sound card, MP3 and other sounds that can only be heard by headphones. Through the multistage amplification circuit in power amplifier, the weak signals are amplified ten times or more.
Different voltages, different power amplifier tubes and different amplifier stages can obtain different power.
The greater the power of the amplifier, the better the sound-all amplifiers are distorted and powerful. If you use less than half of the power, you can hardly hear the distortion, so the power amplifier with high power is better-100 w * 2 is called hi-fi power amplifier. Because of its high power, we listen to music with 30-50W power, and the distortion is relatively low.
If the power amplifier is only 50W, we will seriously distort the sound of 50W-the sound will be ugly.
There are two kinds of power amplifiers: Class B and Class A, and what we usually see is Class B power amplifier. Although this kind of power amplifier has high distortion rate, its cost is low, and its sound quality is better below half of the total power, so it is adopted by many manufacturers and generally accepted by consumers.
Class a power amplifier has the best sound quality. As long as it is turned on, it will run at full power and high current even if it doesn't work (similar to the working principle of class A tubes), so it is very close to the tubes opposite the tone-it also has sweet and warm sounds, and like the tubes, the distortion rate is very low.
Transistor is a new technology, which is much more advanced than the old technology of electron tube decades ago-no matter the low frequency intensity or the huge dynamic surge of power output, electron tube power amplifier can't compare with it. . .
Although the electron tube is not as good as transistor A, it is mistaken that the electron tube power amplifier is the best power amplifier because of its better sound-better than the general class B power amplifier-in fact, this is a big misunderstanding-class A transistor is the best power amplifier at present.
Why is Class A power amplifier rare? In fact, there are, but the materials used are relatively large-the heat output is large, the radiator is huge, the filter capacitor is huge, and the price is relatively expensive: a famous HI-FI amplifier of 100W*2 costs 2,000 yuan, and a Class A amplifier of the same brand costs more than 3,000 yuan, and the power consumption is as large as that of a vacuum tube amplifier.
Because there are many traditional Class B amplifiers, they occupy almost all consumption channels. There are also many people who publicize and understand the electron tube power amplifier, because the electron tube used to be the mainstream product.
However, few people know about the excellent Class A power amplifier with new technology, so the lack of sound knowledge and publicity is also a main reason why Class A power amplifier cannot be known to everyone.