TDA7377 Multipurpose Single Power Dual Track Subwoofer Audio Amplifier Board Kit | Walmart Canada
HiFi Class A Assembled Amplifer Board Mono Channel Subwoofer Power Amp 600W DIY | eBay
Amazon.com: CYOEST DIY Bluetooth Speaker Box Kit Electronic Sound Amplifier - Build Your Own Portable Wood Case Bluetooth Speaker Sound - Science Experiment and STEM Learning for Kids, Teens and Adults : Electronics