sound amplifier 

This class D amplifier is made on two TPA3116D2 chips. One provides amplification for the right and left channels of 50 W each, the second amplifies the sound of the subwoofer by 100 W. There are three potentiometers on the amplifier board, one works as a volume control, the second is a subwoofer volume control, the third is a channel volume control. There is also an LED power indicator on the board. In addition to the amplifier chips on the board, there are NE5532 chips for selecting the frequency range of the channels.