How to make your own amp and speakers

Step Four – Add connectors, an amplifier chip and batteries
Insert and solder your two terminal block connectors to the board – these will connect via wires to your exciters – and two potentiometers (variable resistors) too. Insert the IC amplifier chip carefully into your 8 pin socket, then solder the battery holder onto the board from behind and test it with 2 AA batteries. Turn the switch and the LED should go on – if not get troubleshooting.

If it's all good, take the battery holder off and attach some double sided foam tape then unpeel one sticky side. Solder the holder's legs onto the underside of the board near to the IC then test out the LED again.