A simple amplifier 02

Printed circuit board diagram. Due to the simplicity of the circuit, printed boards can be made using the shovel engraving method. There is no need to drill holes in the circuit board .
Just use sandpaper or kraft paper dipped in a small amount of water to polish it, wash it with water and dry it,
apply a layer of rosin alcohol solution, and then solder the components directly to the copper foil
surface.
    After soldering, check that it is correct, then connect the power supply without connecting the speaker first ,
then the voltage between the positive and negative output terminals should be less than 0. iv. Connect the speaker
, touch the input terminal with your hand, the speaker should make a loud "buzzing sound" 6,
then you can input the signal for sound test.