small wooden rooms: 2 313 pocket synth idea

The image above is my guitar and mandolin.

Last night I was working on some designs for a polyphonic square-wave pocket synthesizer. It should be an interesting project. The design uses 555 timer chips to create a square waveform, the pitch is defined by a variable voltage (a 2k trimpot) and a button that closes the circuit. Every two notes is linked to the same IC, so it's not completely polyphonic. I did this because it was unreasonable that someone would play both a C and C# together at the same time. The same applies for every other two linked keys. Because there are 13 keys used, from C to the octave above, 7 555 chips are used.

The image below shows a simple schematic layout of it.

A new shipment of electronics components from Tayda Electronics is destined to come in the next few days. I strongly recommend this site for electronics projects. The package includes parts to build an EHX Sovtek Big Muff for a friend, and two passive mixer boxes with LED VU meter, for me and a friend.
I hope to fit the pocket synth circuit on one of these 120x80mm prototyping boards.