Make a simple power amplifier-BC547 – 1watts

This circuit is probably my most used AF power amplifier circuit in my own homebrew equipment.This circuit will deliver the full 1 watt output with about 400mV RMS of drive voltage, but for other input levels you can set the gain by adjusting the value of R8. The gain is equal to 1 + R8/R5. For full output power the output voltage is 4volts RMS (12v Pk-Pk) with a 13.8 volt supply. With a 4 ohm speaker and heavier output transistors you should be able to get up to four watts of AF from this amplifier. Supply voltage for this amplifier is 13.8 volts. You can replace the output transistors TR3 and TR4 with transistors having a higher current rating and drive speakers of just a few ohms to get more power out. This circuit is a very suitable circuit for homebrew receivers.
af amp-1w

R1 100R R2, R3, R4 47K
R5 470R R6 470R*
R7 1K0* R9, R10 1R0
C2 1uf C1, C3, C4 2200uf
C5 10000uf TR1 PNP BD557
TR2 NPN BC547 TR3 NPN BFY51
TR4 PNP BFX88 Diodes 1N914