Review on Nobsound 100W Full Frequency Mono Channel Digital Power Amplifier Audio Mini Amp (Black) – Superior Sound Amplification for Audiophiles by Byron Forman

Small built-in loudspeaker for musical instruments. This offers a compact amplifier without much heat. Things to note: The negative side of the power supply is connected to ground, as is the common side of the input connector. However, both outputs are floating between ground and positive power. Anything you connect as a load must be isolated. I drove the amp with a signal generator and looked at the output with an oscilloscope to see how much switching noise there was at the output. The oscilloscope probe ground has been connected to the power line ground. There was also a signal generator. As a result, I shorted half of the output. I was sure I had blown up the amp. Not correct! Still works great.