Dilshan R Jayakody’s Web Log

The Arduino Mini Amplifier is a compact audio system that merges vintage analog and modern digital components. It combines a Philips TDA8425 audio processor and an Arduino Nano , supporting Bluetooth and line-in audio, spectrum analysis, stereo modes, and software-controlled tone adjustment. Finished prototype of the Arduino Mini Amplifier. The Arduino Mini Amplifier is organized into six major subsystems: the audio processor, spectrum analyzer, Bluetooth source, power amplifier, control interface, and power management unit. This modular setup allows each part to operate with minimal interference from the others, making designing and PCB routing easier. The system uses separate paths for analog and digital ground signals (these are called GNDA for analog ground and GNDD for digital ground). Their connections are limited to specific points, which helps prevent unwanted electrical noise from the MCU from reaching the analog audio circuits. The audio section is centered on the T...

Recently we looked for a replacement class-D power amplifier to replace my old TDA2030 power amplifier build . While searching for a suitable power amplifier IC, we found TPA3001D1 from the local market. This IC is a slightly older 20W Class-D power amplifier manufactured by Texas Instruments . At the time of this writing, it is priced at LKR 180 (0.89 USD) in the local market and is still available at all major electronics stores (including online stores ). Prototype version of TPA3001D1 power amplifier. To minimize assembling difficulties, we used through-hole-type components in this PCB. The only SMD component in this PCB is the TPA3001D1 IC. We installed the power amplifier IC on the bottom of the PCB because then it would receive good airflow. The table below lists all the components required for this project. Designator Quantity Value C1 , C8 , C13 , C14 , C15 , C16  6  1µF/25V C17  1  10µF/25V ...