Hi, and welcome to my store! I'm Caspar, or Kassu, and I'm a Dutch guy living in the lovely country of Finland.

I started building and designing modules for modular synthesizers out of interest for sound design and to learn about the circuits behind classic syntesizer functions. By studying schematics and explanations on great synth DIY sites by legends such as Yves Usson, René Schmitz, Ian Fritz, Ray Wilson and others, I started to grasp some of the concepts and ideas. To share what I learned I started my own blog Kassutronics, with schematics and explanations of my versions of classic module designs.

Initially, I made all my modules on prototyping boards, laying out the parts as I go. This is a lovely way of working, but also time consuming and not encouraging making many of the same module. Eventually I started working on proper PCB designs, which immediately raised interest of the rather active Finnish synth DIY community. After sharing some first rough-around-the-edges designs with the local community, I decided to put more effort in finishing the designs and, starting with the VCO 3340, selling to the general synth DIY audience.

From the start I have used plywood as the material of choice for front panels. It's easy to work with, and I enjoy the warm look and feel in contrast to the harsher aluminium panels that I know all too well from my work in experimental physics labs. For prototyping and one-offs I either make the panels by hand, or engrave and cut them at the laser cutter which is provided for free in my local library. The front panels that I sell in this store are made professionally by Laser Cut Studio in Helsinki. They use very high quality Finnish birch plywood, and the artwork is printed on a white painted background, giving clear fonts and much higher contrast than laser engraving.

Copyright and reuse information

All the PCB designs, artwork and documentation are copyright by me, Caspar Ockeloen-Korppi and should not be re-used for commercial purposes (except re-selling items bought from me). However, in the spirit of synth DIY I allow and encourage re-use of schematics and ideas for personal use. Feel free to make (variants of) my modules on stripboard, protoboard or even design your own PCBs for personal use. If you design a PCB from my schematic, you can order a pack of 10 and share the left-overs with friends at cost. However, I ask not to sell PCBs based directly of my designs in volume or for profit, nor share such PCB designs to the wider public.

Of course many (parts of) the circuits are derived from classic synth designs and datasheet suggestions, and I do not intend to make any claim of ownership of such designs.