What are audio power circuits and what to know about them

When we buy sound systems, karaoke systems, we may have to buy amps with the main component of the audio power circuit. So what are audio power circuits, how are their properties and classifications? Let’s find out with Tnhelearning.edu.vn through the article below!

What is an audio power circuit?

In the audio field, audio power circuits are known as “black boxes” with the English name Power Amplifier , many people will refer to them as Power Department for short . Unlike home audio amplifiers, they often do not have the tuning circuit and treble-bass knobs or other tone controls like on the mixer, because they are not needed.

All signals have been processed in the previous frequencies such as: Mixer, Effect, Equalizer, Compressor etc… and the Power circuit is only responsible for adjusting the signal power for the circuit to output the speaker.

Properties of an audio power circuit

Some of the properties that you often see on audio power circuits include:

• Input: 6mm or XLR signal jack, low impedance (~600 Ω) balanced or unbalanced. The standard input signal voltage is 0dB ie 0.77v.
• Output: The power circuit is responsible for adjusting the audio signal into a large-capacity AC signal from a few tens, several hundred to several thousand watts at a typical load speaker impedance of 8Ω . The voltage is from a few volts to a few tens or a hundred volts . Usually the speaker output can be a 6-mm jack , but because of the need for a large capacity load, many times people use a screw or a larger jack called a speakon jack . Especially the speakon jack can also accept 6-mm jack.

Classification of commonly used audio power circuits

Circuit using electronic lights

This is a type of audio power circuit with a total impedance of the cabinet speaker of 4.8Ω . Although the circuit using electronic lights is no longer as common as other circuits, it is still popular for use in guitar amplifiers or in classical vinyl music amplifiers.

The circuit uses transistors and has a negative output transformer

The circuit uses a transistor and has a sensor that outputs the sound, which has the advantage of being able to use a low voltage source , so it is beneficial when we use a normal power source. In addition, transformers can also be used to raise the total impedance and output voltage to high (100 volts, several kΩ) , which is beneficial in conducting long distance speakers and using many small speakers , in which we can turn on / off many speakers without affecting the operation of the system.

This type of circuit has the characteristic of being durable , withstanding being dropped or short-circuited by the speaker wire without flammable or damaged. The impedance has 2 levels: low is 4.8Ω and high is 75 to 100 volts.

Circuit using transistor or power FET without negative pressure

Realistic sound, great power but is characterized by only operating with low impedance 4.8Ω – sometimes 2Ω.

Bridge connection

This is not a specific type of power circuit, rather it is a way of connecting the speaker output . In this connection, two identical and separate power circuits are connected together , the input signal is arranged in reverse phase at the two inputs, and the output is the two hot ends of the speaker output line and the cold line is connected. connected in succession.

Mathematically, when the output voltage and current are connected in that way , the output will be 4 times the rated power . And bridge-capable power amplifiers, as well as large power units, are very heavy, because they require huge transformers and power supplies .

Above is some information about audio power circuit, hope the article will bring you more useful information.