DIY Power Supply Mod for Handheld Amplifiers

If you're interested in modifying a power supply, this article might be worth a look.

If you want to add an amplifier to your handheld device but don't have the right power supply, you can follow along and do a computer power supply modification.

The chip you'll need for this is the KA7500B. Start by connecting two 10K resistors in series from pin 1 to ground. However, this might result in a voltage that's too high, such as 14.8V.

If you encounter this, simply add another 10K resistor in series to achieve a total of 30K.

13.65V should be sufficient for most uses, so you don't need to aim for exactly 13.8V. However, if you really want 13.8V, you can add a 27K resistor in series to fine-tune it.

Finally, you'll need to cut off any unnecessary wires and secure the remaining ones with electrical tape. Then, add two terminals for the output.

You can use the original output port to install a switch that controls the connection between the green and black wires.

And that's it—you're done!