Review on Douk Audio Upgraded 50W+50W Wireless Bluetooth 4.0 HiFi Audio Receiver Digital Amplifier Board with Case and Heatsinks: Enhanced Audio Performance and Protection by Aaron Clayton

I bought this amp to power a pair of refurbished 4" bookshelf speakers in my garage. It's not that powerful, but for small speakers at reasonable volume, it's a great amp for the price. Distortion gets quite severe at high volumes, so if loudness is what you're looking for, look out for something else that's stronger. (when connected) is not as advertised but wasn't difficult to find and connect. Even in an acrylic case the dimensions are tiny. The 12V 6A power supply I use for this is larger than the amp itself. If you do that If you want to mount the unit vertically to regular drywall or a wooden wall, you may need to get creative as the screwed magnetic feet also hold the case together. I ended up cutting and painting a small piece of sheet metal to attach to the drywall. Overall I think this amp is a great buy for less than $30. It's compact, easy to set up and use, and packs plenty of power for small to mid-sized bookshelf speakers.