Now with the VCO, VCA and ADSR i have a basic minimal synthesizer. Every module is self designed or a renewed design of an existent older module. This modules makes a basic patch for playing around.

Basic Synthesizer

Those Elektor Formant based VCO modules are tracking that well together that i thought it is worth to dig up a rather old project of mine. I have made a working prototype some years ago and then forgot about it. A keyboard scanner. This makes my synthesizer to a poly synthesizer!

Keyboard Scanner

On the left you can see the “keyboard” and underneath the keyboard electronics build with 4014 and the PCB from the German computer magazine C’T, issue 17/2005. Yes, this prototype is that old. On the stripboard on the most right is the sample and hold part and under that (not visible) the microprocessor, the discrete digital – analog converter (R2R ladder) and some multiplexing and switching circuitry.

Keyboard Scanner Block Diagram

But before going into building the keyboard scanner I will build a waveshaper and some filters.