The amplifier works on 12 Volts which may be tapped from inside the computer. A socket is fitted for connecting the speakers, and the input is fed in by a cable to be terminated in a stereo EP jack.
Step 1: Tpa1517 Stereo Amplifier
The chip, two large electrolytics, and three smaller capacitors will make the amplifier complete. I am adding an output socket too, on board. The input shall be via a stereo cable and there has to be a 12 Volt supply line, as well.
The picture is of the major components arranged on a blank piece of PCB.
Step 2: Populated Board
The capacitors are connected with flexible wire taken from Hard disk flat cable, and so the input capacitors can move and short out. They shall be placed in position and encapsulated in hot melt glue.
Step 3: Ready for Potting
If the regular epoxy potting compound is used, this won't be that easy.
A sort of enclosure is made by taping thick paper around the board, and the hot melt glue melted and flowed around the components using my hot air tool fitted with a narrow nozzle.
Step 4: The Finished Board
A red LED has been added to indicate power. A zener diode protects against reverse polarity and excess voltage. Some copper foil has been soldered to the thermal pad of the chip.
The components are held immobile by the hot melt glue, yet they may be rearranged by heating using a soldering iron.
The chip is rated to work for supply voltages between 9.5 volts and 18 volts. The zener is of 18 volts. It will conduct if the voltage is applied in reverse, or if the voltage goes above 18 volts.
It might fail short circuit if the fault current is too high, thus protecting the chip. It has been mounted outside the hot glue, to be easily replaced.
Step 5: Component Layout
Or if somebody wishes to duplicate this project.
Step 6: Connections Labelled
The completed board fits into the shell of a 9V PP3 battery.