What Must todo

This circuit is circuit use the IC TDA1904 and IC TDA1905.
See schmatic below :

Technical instruction :
Minimum supply voltage   : 4 volts
Maximum supply voltage  : 20 volts
Minimum currents             : 40 mA
Input can with                    : CD , Tuner , Tape , Preamp Mic , Media Player device.
Maximum Power Output   : 10Watts
Minimum Power  Output   : 4 Watts
Impedance Speakers          : 4 Ohms