Yda138-e Digital Amplifier Board 20w+20w Dc 12-15v Class D Audio Stereo Hifi Amp For Yamaha Speaker Xh-m531 With Volume Control - Operational Amplifier Chips - AliExpress
YDA138 Datasheet(PDF) - YAMAHA CORPORATION
Yamaha YDA138 class D stereo amplifier board test & review - YouTube
YDA138-E Digital Stereo Audio Power Amplifier Board DC12V 10W+10W | eBay