Stereo Amplifier Dual Supply Circuit Diagram

Introduction

A stereo amplifier using LM1877 IC is a powerful and compact device capable of amplifying the sound output of any audio device. The LM1877 IC, also known as the National Semiconductor LM1877N-9, is a stereo audio amplifier that is specifically designed for use in high-end stereo applications, especially for musical instruments and public address systems. This IC is known for its high gain, low distortion, and fast slew rate. When operated with an 8-ohm speaker. In this article, we will discuss the stereo amplifier dual supply using LM1877 IC operating with a dual split power supply and 8 ohms speakers.

Operating Principle:

The LM1877 IC is a dual power amplifier that consists of two identical amplifiers of 1 watt each. These amplifiers are designed with a fast slew rate and a wide bandwidth, which makes them ideal for driving small speakers. The LM1877 IC is specifically designed to operate with a dual split power supply, which means that the positive and negative terminals of the amplifier are supplied with two voltages of equal magnitude but opposite polarity. The voltage difference between the positive and negative terminals is known as the supply voltage, which determines the maximum output power that can be delivered to the speaker.

Circuit Diagram

of Stereo Amplifier Dual Supply

The following is the circuit diagram for a stereo amplifier using the LM1877 IC operating with a dual split power supply and 8-ohm speakers.

**Stereo Amplifier Dual Supply Circuit Diagram**

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The circuit uses two LM1877 ICs to drive two 8-ohm speakers for stereo sound. The ICs are powered using a dual split power supply that consists of a transformer, a bridge rectifier, and two voltage regulators. The transformer reduces the AC voltage from the mains to the required level, while the bridge rectifier converts the AC voltage into DC voltage. The voltage regulators are used to regulate the DC voltage to the desired level. The negative voltage regulator is connected in series with the positive voltage regulator to obtain a dual split power supply.

Components List

of Stereo Amplifier Dual Supply

The following is a list of components required to build a stereo amplifier using the LM1877 IC:

LM1877 IC
Transformer – 12V-0V-12V, 2A
Bridge rectifier – 1N4007 x 4
Voltage regulator – LM7809 & LM7909 x 2
Electrolytic capacitor – 2200μF, 35V x 2
Ceramic capacitor – 0.1μF x 4
Resistor – 100kΩ x 2
Resister – 2kΩ x 2
Resister – 2.7kΩ x 2
Dual Pole Potentiometer – 100kΩ
8 ohms speaker x 2
Stereo audio jack x 1
Power socket x 1
Printed circuit board (PCB) (optional)
Connecting wires

Working Explanation

of Stereo Amplifier Dual Supply

The following are the steps to build a stereo amplifier using the LM1877 IC operating with a dual split power supply and 8 ohms speakers.

Solder the LM1877 ICs, capacitors, resistors, and potentiometers on the printed circuit board (PCB) following the circuit diagram.
Solder the bridge rectifiers on the PCB and connect them to the transformer.
Connect the voltage regulators to the PCB and connect them to the bridge rectifiers.
Solder the stereo audio jack and power socket on the PCB.
Connect the 8 ohms speakers to the PCB.
Connect the potentiometers to the PCB.
Connect the input cable (with a 3.5mm jack) to the PCB.
Connect the power cable to the PCB.

Testing:

The following are the steps to test a stereo amplifier using the LM1877 IC operating with a dual split power supply and 8 ohms speakers.

Connect the input cable to the stereo amplifier.
Connect the power cable to the stereo amplifier.
Turn on the power supply and observe the LED indicator (if available).
Adjust the volume using the potentiometers.
Play a music file from an audio device and observe the output sound.

Applications:

The stereo amplifier using LM1877 IC operating with a dual split power supply and 8 ohms speakers has a wide range of applications such as:

Home entertainment systems – the stereo amplifier can be used to amplify the sound output of a TV or DVD player.
Public address systems – the stereo amplifier can be used in small public address systems such as for indoor meetings, parties, or gatherings.
Musical instruments – the stereo amplifier can be used to amplify the sound output of musical instruments such as guitars, keyboards, and microphones.