Power amplifiers are the core of audio systems. The amplifier does its best to ensure a high-quality auditory experience. If you are not familiar with the working principle of amplifiers, this article will cover all the content related to power amplifiers. At the same time, we will also show you some special examples to illustrate which device is most suitable for you as an audiophile.

What Is The Function Of An Amplifier?

A power amplifier is an electronic amplifier designed to increase the power of a specific input signal. Therefore, the power of the input signal is increased to a level sufficient to drive the load of output devices such as speakers, headphones, RF transmitters, etc. Power amplifiers are used in many different fields, so there may be significant differences in power amplification power output. For example, a portable headphone amplifier may only have an output power of 10mW. However, this is enough to drive the headphones to achieve a loud listening level. The output power of the power amplifier used for speakers in sound reinforcement systems may range from 1 to 4 kW (depending on the power level of the speakers). Power amplifiers used in professional recording studios typically do not have a power output exceeding 1 kW.

Why Do We Need An Amplifier?

An amplifier is the core and soul of an audio system. The power amplifier uses low voltage (electromotive force). Then it sends it into a transistor or vacuum tube, which acts like a switch and quickly turns on/off based on the amplified voltage from its power source. When the power of the amplifier is supplied, the power enters (input signal) through the input connector and is amplified to a higher voltage level. This means that the low-power signal coming out of the preamplifier is raised to a level sufficient for the speaker or headphones to reproduce sound, allowing us to listen to music with our ears.

How Does an Amplifier Work?

The power amplifier works together with the preamplifier to obtain a small voltage from the output of the preamplifier and convert it into a higher current signal, which is driven by a transistor or vacuum tube to drive the speaker's voice coil. For example, a Class A mono power amplifier obtains an input signal from the signal source in its input stage, amplifies the signal into another amplified version, and sends it to the power output stage.

Why Use an Amplifier?

If you have an amplifier, it can be helpful when you want to obtain greater power than the line output on your sound card can provide. For example, if you use a cheap computer speaker without amplification function, and you want a louder sound, you need an amplifier. Due to the low voltage generated by the analog sound card, the line output cannot provide sufficient power. Some amplifiers can even power headphones, so the power you receive is greater than what your headphones can provide. Some HiFi speakers have high impedance and are usually difficult to drive, and power amplifiers are necessary.