It has been a long time since something happend here, but in my defence i was very lazy.

I added an RC lowpass filter and an output driver with volume control to the Synthe555er. This is the schematic, exciting stuff i know.

Again, to keep up with the tradition, there is no NE555 in sight. But i was trying. The original name for this project log was "voltage controlled frequency controlled bandwidth lunacy". Let's leave it at that.

Instead have a look at the finished board:

Additonaly i build two extra keyboards. Now i can play three octaves.