We examined sound waves and an Electronic Circuits, by putting together a small keyboard.
The synthesizer is build around the NE555 timer chip and a resistor-ladder.
Parts
Diagram
Below is a screenshot from »Engineer’s Mini-Notebook« by Forrest Mims from 1984. This version uses a lot of different capacitors which makes it more expensive. The previous DIY version shown above is very cheap compared to this one.
