This is an AIMOR digital amplifier BK-DA10, often seen in commercial amplifiers, karaoke amplifiers, etc. I used to use it, but the sound would sometimes cut out or become unstable depending on the volume position and the time it takes for the transformer to stabilize after turning it on. It might work after restarting the power, or by adjusting the volume up and down, which I believe is due to the deterioration of internal components. However, if it plays at a certain position, it can be used normally, so please consider it as a defective item. I felt that the sound quality was better than other similar karaoke amplifiers.