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 Mark Dahmer

Definitely not 50x50 watts but still works. Too bad it didn't have a power switch, I had to buy an on/off switch separately. Poor sound quality at any volume - there's always background noise and a hiss/hum/squeal when no music is playing. When turned on, it plays a LOUD tone indicating the power is on - I wish it was a little quieter. DIP switches don't affect sound quality, only volume. Think a little static and lower audio quality, then this works great. For music or even talk shows or podcasts I'd avoid it just for the annoying buzzing static sound that's always there. Sounds like an old AM radio. Bluetooth works fine. Easy to combine, the range is sufficient. I used this in a homemade bluetooth speaker enclosure. Although I could look for a better amp.