Below the scheme uses TDA 2002 as an amplifier. The scheme produces 4 Watts when powered 15 Volts. The minimum input signal 95 mV with pre-amplifier on the scheme and 0.65 In without him.
Components used:
R1
2.2 KW
R2
330 ohms
R3
4.7 Ohm potentiometer
R4
330 Ohm
R5
1 kOhm
R6
1.5 W
C1, C6
100nF (polyester)
C2
100mF/25V (electrolytic)
C3, C7
1mF/25V (electrolytic)
C4
1000uF/25V (electrolytic)
C5
10uF/25V (electrolytic)
Q1
BC547
U1
TDA2002
LS1
The loudspeaker.
Notes:
Proportional to the impedance of a speaker varies the output power, respectively:
LS1
Output power
2 Ohm
6,5 W rms
4 Ohms
4,2 W rms
6 Ohms
3W rms
8 Ohms
2,25 W rms