Blog  /  Audio Amplifier- A Brief Outlook to Its Many Types

Audio Amplifier- A Brief Outlook to Its Many Types

With the touch of modernization, technology is evolving faster, where many new inventions are crawling to the surface. Each device or technique you encounter sets you in awe of surprise and amusement. Today, machines have taken up the world and are assisting the masses in their everyday chores.

When learning about the audio Amplifier, you will find how each section of the device can help you make the most out of your devices, whether the lyrical flow of your lead guitar or the blasting speakers of your luxury car.

audio Amplifier
The audio Amplifier is of many kinds, and it can be challenging to choose one according to your requirements. Whether it is for your home theater system or your car, selecting an audio amplifier can leave you very confused.

In this article, you'll get to know some of the prominent audio amplifiers along with their specifications. Moreover, in this article, you'll be introduced to DIY audio speakers so that you can create one which meets your needs. What is Audio Amplifier?


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1、Audio Amplifier


1.1 What is an audio Amplifier?


Audio Amplifier1


The audio Amplifier is the electronic Amplifier that tends to enhance the strength of electronic signals passing through it. It reproduces low power signals to make them strong enough to drive loudspeakers. For instance, the device receives signals from an electric guitar pickup then produces a low-power signal to a level that it powers the earphones or speakers.

The audio signal adjust the tone, effectiveness of the pitch, and effects of the signs. It enhances the performance of any electronic audio device. When plugged into a car or in a guitar, it helps adjust the sharpness and frequency of the Audio.

In order words, if the Amplifier receives a hundred microwatts, it will reproduce the signals delivering only ten microwatts of signs. Its manufacturing involves functions, including frequency, distortion, noise, and gain.


Audio-Amplifier4Image 1: Audio Amplifier


1.2 Professional Audio Amplifiers


With the advent of various technological devices, there arises a need to create different amplifiers suiting to the unique needs of every technology. In the audio market, some types surfaced over the years that assisted users in boosting the effectiveness of their devices by adjusting signals in the best possible manner.

Classified into different categories, the types of amplifiers offer additional functionality and possess various features as per their classes. Learn about the most common seven classes:

Class A Amplifier

It is one of the simplest amplifiers of all with output transistors to conduct. It offers comparative lower efficiency output signals.

Class B Amplifier

There is a push and pull topology involved in Class B Amplifier, where the outputs have two terminals, a negative and a positive one. It's a bit more efficient than Class A as it replicates the input signals only during the half-cycle at 180°.

Class AB Amplifiers

It is a blend of A and Ab amplifiers. It delivers the best functionality traits from each of the two individual categories: the efficient sound quality of Class A and the level of efficiency from Class B.

The two popular versions of Class AB, the MAX98309, and MAX98310, are used in digital cameras, media players, e-readers, and tablets in which a high fidelity is required.


Audio Amplifier2


Class D Amplifier

It is a highly efficient version of audio amplifiers, which reduces power consumption. It keeps the device working for longer, eliminating the need to recharge the batteries. In its functionality, the output transistors are turned off during the operation, thus eliminating the need to use linear regions present on the transistors, contributing to the Amplifier'sAmplifier inefficiency.

Class G Amplifiers

It is a more advanced and efficient version of Class AB Amplifiers. The Class G amplifiers require two or more supply voltages. When it operates at a low signal level, it automatically selects the appropriate level of the supply voltage.

Class DG Amplifiers

Much like Class D amplifiers, the DG amplifier uses pulse-width modulation for producing digital output signals having variable duty cycles. It shows a bit of advanced functionality by using a multilevel output stage that helps sense the magnitude of output signals.

Class H Amplifiers

Like the Class G amplifier, it uses the technique to reduce dissipation around the output devices. The topology of Class H minimizes the voltage by modulating its supply voltage across the outputs.


Audio-AmplifiersImage 2: Audio-Amplifiers


2、An Early History of Mini Audio Power Amplifiers



In 1906, the first audio Amplifier was manufactured, which consisted of a tube-like mechanism. Lee De Forest created it in the form of a triode vacuum tube. It involves significant black infrastructure having huge output tubes, which are used to release much Heat.

In the 1970s, silicon transistors replaced this technology, which these tiny transistors use to reproduce the sound by changing the voltage using semiconductors. As time passes, reliable state transistors came into being. It is commonly known that many of the current amplifiers are, in some way, a form of solid-state transistors. A bipolar junction transistor is a perfect illustration of Solid State amplifiers.

With the technological evolution, in 1872, Matti Otala came up with the reason for the dissertations produced in the former versions of the Amplifier, and he manufactured a modern face of mini power amplifiers. Some of the famous mini audio amplifiers include the following:


Image 3: Audio

2.1 Quantum Audio Amplifiers


As per physics, the functionality of the quantum amplifier is based on that of quantum mechanics. The device uses quantum mechanical techniques and phenomena to amplify the quantum signal.

In other words, an amplifier increases the amplitude of the signal that passes through it; however, the quantum amplifier takes in the signs present in the coherent state. At the output, the Amplifier intensifies the input. Moreover, it can also amplify the quantum noise, which is present in the signal.


Audio AmplifiersImage 4: Quantum Audio Amplifiers


2.2 VM Audio Amplifier


A VM amplifier is the first asset of a professional guitarist. It adjusts and moderates the pitch, distortion, and frequency of the sound. The devices reproduce the digital signals and offer functionality, including reverb, depth, gain, drive switch, cover, mix, and significant adjustments.


Image 5: VM Audio Amplifier


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3、DIY Audio Amplifiers



Making a first audio amplifier, mainly based on the LM386, is quite simple. The hardware components used to make this simple Amplifier include:

1. Texas Instruments LM386
2. 9V battery
3. Resistor 10k Ohm
4. Capacitor 220 µF

The LM386 is a low-voltage audio power amplifier suitable for battery-powered devices like hobby electronics projects, guitar amplifiers, and radios. Moreover, the IC consists of an 8-pin dual in-line package capable of offering an output of 0.25 watt to 1 watt of Power with a 9-volt power supply depending on the model.
Components used


Audio Amplifier3


Apart from the components listed above, you'll also need:

1. A Speaker
2. An Audio jack
3. Connections

While this might seem a little troubling, connections are pretty easy
The 9V ground negative will connect at pin two and pin 4.
The 9V battery positive terminal to be connected to pin 6
The positive terminal of the capacitor will be attached at pin 5
The other pins will have no connections.

Other connections you'll have to make include:
Negative terminals of the speaker connected to the speaker
The other end of the resistor connected to the Audio IN

After making the connections, you need to solder the components together. Ensure you use a PCB (printed circuit board) instead of point-to-point soldering, as utilizing a PCB is much more comfortable. Finally, check the connections and test out your Amplifier!


4、Car Audio Amplifiers



Amplifiers are the first element that fine-tunes your car sounds. You may not be able to see the parts of the Amplifier, but it is buried inside the car. It helps you enjoy the fun of loud music and to indulge in the rhythm of the music. If you do not install an amplifier, you will never experience the quality of music.


4.1 Specification and Functionality of Amplifiers


Audio Amplifier4


• Preamplifiers of the Car Audio System


The functionality of the Amplifier slightly differs in the car audio system, where more than one pre-amplifiers are used to price the signals. The Amplifier boosts the signs to let them move the speaker cones for creating a sound. However, before simplifying the sound, the signals are processed using the "preamp."

In the car system, the preamp has to collect the many different signals from the various car heads, including CD ROM, and radio to output them to the Amplifier.

In short, it helps the Amplifier to adjust the base, do the equalization, and fine-tune the sound.


• Crossing Over


In the stage of passing over, the preamp performs processing in which it divides the full range of audio signals into separate frequencies. It regulates movements to the different categories of speakers like woofers and tweeters.


•Power and Heat


During the preamp processing, the Amplifier releases a massive amount of Heat that alters the electric current working in conjunction to create sound. In an automotive environment, tube amps are not recommended to use since they generate heat and vibrations.

Therefore, an alternative electronic transistor amplifies the audio signal. The Amplifier boosts the line-level signal using electronic components such as resistors and capacitors. The amplifiers do generate Heat during this process. But they are manufactured in such a manner that they do not experience overheating.


5、BJT Amplifier Circuit


5.1 What is a BJT Amplifier?


Bipolar junction transistor (BJT) includes two semiconductors material forming a PN-junction. It is created by joining the two conductors back to back. You get two terminals, namely P and N. Upon combining the two airports, And you get a three-layered transistor having two junctions. It forms the basis of a Bipolar Junction Transistor.


Audio Amplifier5


5.2 The Functionality of Bipolar Transistors


Wile, a standard transistor, is a three-layered or commonly called a three-terminal device manufactured using different semiconductors. It offers functionality as an insulator and as a conductor. This ability of transistors makes them perform two essential functions, which include switching and amplifying.

Three different regions are involved in bipolar transistors, namely:

•Active Region


5.3 Bipolar Transistor Configurations


In the bipolar transistors, the three most essential terminals are included, which are called the Emitter, Base, and Collector. Having three terminals opens three ways to connect each of the two to form a transistor. The typical combinations are listed below:


Common Emitter Configuration.


I this arrangement, the transistor can deliver a medium input to medium output impedance. It provides a high voltage and current gain.


Common Emitter ConfigurationImage 6: Common Emitter Configuration


Common Base Configuration


This arrangement is commonly used for making RF applications where the terminals deliver a low input to high output impedance. Usually, the current received is low while the voltage gain is higher than it.


Common Base ConfigurationImage 7: Common Base Configuration


Common Collector Configuration


Commonly called the Emitter follower, this configuration provides a high input to low output impedance. Here the voltage gain is much lower than the current.


Common Collector ConfigurationImage 8: Common Collector Configuration


6、How to Choose the Right Custom Amplifier



Do the many technical features of an amplifier befog you when choosing the one you want?

Do you the things you should look for in an amplifier before you hand over the cash?

The guide below summarizes the key points which you must focus on when choosing an amplifier. The guide will walk you through the in-depth features and aspects to ponder when laying your hands on any amplifier.


• Amplifier Channels


The foremost thing to look for is the amplifier channels. You have to choose the Amplifier based on your need to have the number of output channels you want. You have to look for that particular type of Amplifier, which is according to your needs. Many amps are there, having two-four or mono sub-ports. By having an amp with many ports, you can experience the versatility and power hue devices.


• Power of Amplifier



Secondly, you need to focus on the Power of your amp. Two kinds of power ratings are there, which are as follow:

• Peak Power


The peak power is the kind of Power that the Amplifier produces for a limited burst. It is not that useful and is seen as the numbers that appear on the amp.


•RMS Ratings


It is the continuous calculation of the amp's power output. You must check the RMS numbers when finalizing the Amplifier.




To know which rating is perfect for your speakers, you can do one thing. Choose the amp, which has higher scores than that of your speakers because the more Power your amp possesses, the better will be the sound of your music. If your speakers show 200-watt RMS, then it is best to go for 250-watt ratings of the Amplifier.


•Amplifier Features


Apart from the ranks and sub-ports of your Amplifier, you must take a look at its features. Then the most recommended features that your Amplifier must have included:

1. High/low-pass filters
2. Speaker level inputs
3. Bass boost


Audio Amplifier


• Amplifier Build Quality


Do you wonder why you should look for a high-quality amp?

A custom board amplifier, which may be of a higher price but depicts the most excellent quality, makes you experience music perfectly. So you get the ports to plug in every primary cable, all at the same time.

You can have a much larger beefier component with a vented heat sink to keep the amp cool and protect it from over-heating. Therefore, in this way, a high-quality amp offers the highest quality performance with better sound.


• Amp Wiring


The last and the most critical section is the amp wiring. Its Wiring can predict the overall performance of your Amplifier. Invest money in purchasing a high-quality wiring kit to make sure that the wires supply Power to the ends of the Amplifier.

You can seek assistance from professionals who can guide you in choosing the right amp wiring and a combination of features according to your needs. As a wrong combination of wiring and amps features can cost you a lot, it's always better to stay close to a professional and guide you to choose the Amplifier that can deliver the best performance and not cost so much.




As a technology geek and as a music fan, you'd want an amplifier ideal for you! To get help with your audio amplifier or to pick an audio amplifier that meets your needs, contact Our PCB today! We will be glad to cater to all the problems you are having with your audio Amplifier!



Special Offer: Get $100 off your order!

Claim your $100 discount by sending an inquiry today. Act now to save on your next project!
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