2N3055 Audio Amplifier Circuit with 741 IC

100W Audio Amplifier Circuit using 2N3055 & MJ2955 with 741 — 2N3055 100W Audio Amplifier Circuit

Introduction

The 2N3055 audio amplifier circuit with the 741 IC is a popular choice for audio enthusiasts looking to build their own amplifier. This circuit utilizes the 2N3055 and MJ2955 transistors for the power output stage and the 741 IC as the preamplifier. In this article, we will delve into the details of these components and explore how they work together to create a high-quality audio amplifier circuit.

2N3055 Transistor

The 2N3055 transistor is a high-power NPN bipolar junction transistor (BJT) commonly used in power amplifiers and linear regulators. It has a maximum collector current rating of 15A and a maximum power dissipation of 115W, making it ideal for audio amplifier applications where a significant amount of power is required. The 2N3055 transistor features a typical gain of 20 to 70, ensuring efficient amplification of audio signals.

MJ2955 Transistor

The MJ2955 transistor is a high-power PNP BJT that complements the 2N3055 transistor. It is commonly used in power supply and audio amplifier circuits to provide the required power output. With a maximum collector current rating of 15A and a power dissipation of 115W, the MJ2955 transistor is well-suited for high-power applications. When paired with the 2N3055 transistor, it helps to achieve a balanced and efficient amplification.

2N4017 Transistor

The 2N4017 is an NPN transistor that serves as a simple switch in the 2N3055 audio amplifier circuit. It is used to control the biasing of the output transistors, ensuring that they operate within their safe operating limits. The 2N4017 transistor has a maximum collector current rating of 0.3A, making it suitable for low-power switching applications like this amplifier circuit. Its low power dissipation and low cost make it an excellent choice for controlling the output stage.

741 IC

The 741 IC is a general-purpose operational amplifier (op-amp) widely used in audio and voltage amplification applications. It features high gain, wide bandwidth, and low distortion, making it a popular choice for audio enthusiasts. The 741 IC has a maximum supply voltage of ±22V and can deliver output voltages up to ±20V. It can be used in both inverting and non-inverting amplifier configurations, making it versatile for various amplifier designs.

2N3055 Audio Amplifier Circuit Diagram

This project can be built using a few basic components. The circuit diagram of this project is shown below.

100W Audio Amplifier Circuit using 2N3055 & MJ2955 with 741 IC — 100W Audio Amplifier Circuit

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You can use 3A to 5A transformer with 24 volts secondary output. Also use high amperage bridge rectifier to convert AC voltage into DC., or build your own bridge rectifier with four diodes of 5 to 6A each.

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2N3055 Transistor Pinout

Components List of 2N3055 Audio Amplifier Circuit

Following is the list of all components used in this project:

2N3055 Transistor x 2
MJ2955 Transistor x 1
2N4037 Transistor x 1
UA741 IC x 1
50Ω Resister x 4
500Ω Resister x 2
15k Resister x 2
2k Resister x 2
5Ω Resister x 1
1k Resister x 2
51k Resister x 1
4.7uF Capacitor x 1
100uF Capacitor x 1
47uF Capacitor x 2
1N4148 Diode x 2
15v Zener Diode x 1

Working Explanation of 2N3055 Audio Amplifier Circuit

Now that we have introduced the key components, let’s explore how they are integrated into the 2N3055 audio amplifier circuit with the 741 IC. This circuit is designed as a Class-AB amplifier, ensuring optimal performance in terms of power efficiency and low distortion.

The input audio signal is initially fed to the 741 IC, which functions as a preamplifier. The 741 IC amplifies the low-level audio signal to an appropriate voltage level that can drive the power output stage. Additionally, the 741 IC provides a stable and low-distortion amplification, ensuring the faithful reproduction of the input signal.

The amplified signal from the 741 IC is then transferred to the output stage, consisting of the 2N3055 and MJ2955 transistors. The core of this output stage is a push-pull configuration, where one transistor (2N3055) conducts during the positive half of the AC signal, while the other transistor (MJ2955) conducts during the negative half of the AC signal. This arrangement ensures efficient amplification and balanced operation of the output transistors, minimizing distortion and improving audio quality.

To control the biasing of the output transistors, the 2N4017 transistor is included in the circuit. It acts as a switch, allowing the bias current to flow through the base of the output transistors when required. By properly adjusting the biasing current, the operating point of the output transistors can be set, ensuring their optimum performance.

Use large enough and solid heat sinks for the transistors for proper heat dissipation. Circuit diagram provided above is a single channel mono version, just replicate it to convert into stereo version.

Conclusion of 2N3055 Audio Amplifier Circuit

The 2N3055 audio amplifier circuit with the 741 IC is a versatile and efficient solution for audio enthusiasts looking to build their own amplifier. By utilizing the power output stage consisting of the 2N3055 and MJ2955 transistors, along with the preamplification provided by the 741 IC, this circuit ensures high-quality audio reproduction with minimal distortion.

The 2N3055 and MJ2955 transistors offer high power handling capabilities, making them ideal for audio amplifier applications. The 2N4017 transistor acts as a switch to control the biasing of the output transistors, ensuring their optimal operation. Finally, the 741 IC provides stable and low-distortion amplification, further improving the overall audio quality.

By understanding the capabilities and characteristics of these components, audio enthusiasts can build their own 2N3055 audio amplifier circuit with the 741 IC.

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