Here..... this circuit is stereo power amplifier , based on IC TDA7370, its nice Intregated Power amplifier , He does not have hre slightest sound buzzing , although power amplifiers without additional reinforcement , such as filters , tone control, etc.
Voltage : 9 to 24 volts
Max. Power Output : 2 x 20 Watts
Impedance : 4 Ohms