Date: 19th June, 2025

Written by: Anyanwuocha-Collins Chibuike Innocent

• Federal University Of Technology Owerri
• Department Of Mechatronics Engineering

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ABSTRACT

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This project presents the design and development of a sound amplification PCB for MP speakers using KiCad software. The process involved schematic capture, PCB layout design and simulation, to obtain a 3D model of the final board. During the schematic design stage, several issues such as voltage spikes and incorrect current flow paths were identified and resolved through proper circuit adjustments and component placement. Additionally, challenges encountered in the PCB layout, including overlapping tracks and poor routing, were corrected using improved routing strategies and design rule checks. The final design resulted in a functional and optimized PCB capable of stable audio signal amplification. This project demonstrates practical skills in electronic circuit design, troubleshooting, and PCB development.

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INTRODUCTION

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Sound amplification is the process of increasing the amplitude of an audio signal so it can drive output devices, such as speakers, at an audible level. It is a fundamental part of modern audio systems, allowing weak input signals from sources like microphones or media players to be converted into clear, powerful sound output. This is typically achieved using amplifier circuits that boost signal strength while maintaining signal integrity.

In practical electronic systems, the performance of an audio amplifier is determined not only by the circuit design but also by how well it is implemented on a Printed Circuit Board (PCB). PCB design plays a critical role in ensuring stable operation, minimizing noise, and preventing issues such as signal distortion, voltage fluctuations, and unwanted interference. Poor PCB layout can significantly degrade audio quality, even when the schematic design is correct.

This project focuses on the design and development of a sound amplification PCB for MP speakers using KiCad software. It involves translating a theoretical circuit into a physical PCB layout, identifying and correcting errors encountered during both the schematic and layout stages, and producing a 3D model of the final design. The work aims to deliver a functional, efficient amplification system while demonstrating practical skills in circuit design, troubleshooting, and PCB development.

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System Overview

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The sound amplification system consists of three main stages: the input stage, the amplification stage, and the output stage. These stages work together to process a low-power audio signal and convert it into a stronger signal capable of driving a speaker.

Block Diagram

System Operation

• The system begins with the audio input, a low-amplitude electrical signal from a media source such as a phone or MP player. On its own, this signal is too weak to drive a speaker directly.
• The signal is then fed into the amplifier IC, which is the core component of the system. The amplifier increases the signal amplitude while preserving its original waveform. Supporting components such as resistors and capacitors are placed around the IC to stabilize the circuit, set the gain, and reduce noise and voltage fluctuations.