I had a set of old computer speakers laying around. I thought to myself, “What could I do with these?”.
Then it came to me. Mini amp!
At first I tried to use the amplifier IC that was on the board in the speakers themselves. But after finding I didn’t have all the right parts on hand, it was easier and faster to buy a LM386 chip already put on a PCB board with the proper components to make a small amp. You can pick these up from Amazon by searching “LM386 amp”. They’ll be anywhere from $5-$7.
I found the box at a garage sale for $1.50. I might have overpaid… The original sticker on the box said $19.99 which I thought was really steep.
I started cutting holes in the box for the speaker, 1/4 inch jack and switch. The box didn’t come with a latch, so I drilled a small hole for a small magnet and put a wood screen on the lid so hold the box closed. A little wiring, a little solder, and a little super glue later, all the components were installed.
I did a quick design of a 9v battery clip to hold the battery in place. Then I hot glued the amp and battery clip in place and I was good to go!