🔈 Put a speaker in it! 🔊

How to add an amplified speaker to practically any device with a headphone jack. In this example Joseph Wozniak introduces two different cheap DIY friendly circuits for putting an amplifier and speaker in a Korg Microstation Keyboard.

Notes:
+ input resistor (150k) was shorted
– input resistor to ground (150k) was replaced with (100k)
volume pot was shorted to max. We used a piece of wire, you may have noticed, the little jumpers didn’t stay connected happy, probably had the iron too hot, things got messy there.
The soldering iron tip picked up some insulation from the ancient UNIVAC wire we harvested to use for such things, please forgive the grease.

more tips in our new DIY section

Class D amp board by SparkFun
Korg Microstation Keyboard, sadly discontinued