For this mini bluetooth speaker project I used a bluetooth module, an audio amplifier chip, a li-ion battery charger/PCM chip, an old HTC phone battery, and a couple high quality Jambox speakers I had from a previous project. Oh, and the almighty Altoids tin.

I had a ground loop in this setup because the bluetooth and amplifier shared the same power source. I tried some voodoo electronics tricks that I don't really understand to try to get rid of the static from the ground loop but didn't manage to improve much at all.

Admitting defeat to the ground loop I sealed it all up, stained the front wood panel and gave it a name befitting of it's angry eyes.