A while ago I picked up a toy keyboard from the thrift store in an attempt to circuit bend the thing into a bass line synth. After changing what little components I could on the thing (pretty much just one resistor that adjusted the pitch), I stopped messing with the thing after I realized it wasn’t doing what I wanted.

I still like the size of the thing though so I held on to the thing so I could try to engineer my own replacement circuit board and create something useful out of it.

Now that I’ve finally started build out a eurorack format modular synth, I’ve pulled this thing out of the rubbermaid I keep all my electronics crap in and decided to give it another go at life as a CV and Gate source. The keyboards made for controlling modular synths are pretty expensive so building a little, cool, portable stand in sounds like a fun project.

Today I brought the board to work so I could get a high res scan of the existing PCB. I dropped that scan into photoshop and manually started tracing out the location of the important holes, pad contacts, and board shape. The next step is to take the file and convert it into a format I can import into EAGLE PCB for the copper layers and use it as a guide for the board shape and drill hole placement.

Hopefully I can also use the design as a starting point on making a 3D printable version of it. If I can get that far, then I’ll be able to throw a kit together that will let people build a few different versions of the thing themselves. Of course it will be able to out put CV and Gate signals, but making it a portable USB MIDI keyboard is pretty tempting too.

Further, since I’ve been able to get my voltage controlled oscillator circuit a bit farther along, I may end up dropping that circuit into this thing as well so it has it’s own synth built right in.

I love these kinds of projects!

Tracing the important parts in Photoshop. The black parts will end up as a single copper layer or hole positions…:

The keyboard!:

Internals…:

Keys…:

All of the important bits…: