Background - how I got interested in this sort of thing

Some years ago now I became interested in the hobby of analog music synthesis. My first project was Ray Wilson's "Weird Sound Generator". I did this with a home etched circuit board, didn't really understand much of it but had a lot of fun in the process. It's a great project for beginners. In fact I'm a big fan of Ray's work and highly recommend his MFOS website and his book on Analog Music Synthesizers.

My next step was one of Ray's "Sound Lab Minisynth". Again I hand etched the board based on Ray's PCB artwork. It took a lot of trial and error to get any sound out at all and I learned a lot about how to, and not to, construct synths. Some of the soldering was substandard and the wiring was definitely a mess. The case was a plastic food container with an aluminium faceplate epoxied on.

It was however lots of fun and even though it's never been perfectly in tune and some aspects have never worked, I was thrilled to get some real "synth" sounds out of it.

From this project however I could see that "normalized", self-contained, synths were a little limiting. My next project was to construct a more traditional modular system. This I assembled using modules from various places - some hand etched using Ray's designs, some strip board and a number of PCBs kindly given to me by my friend and colleague Piotr Rotkiewicz  who has an amazing modular system.

My own modular system is a lot more modest:

Still it has all the basics and given the very diverse origin of the modules is likely unique in the world. The large module on the right is a MIDI-CV converter that I constructed using an Arduino and a 10 bit SPI controlled DAC. I do regret that I only thought to build a single oscillator (but three LFOs!) however it's perfectly usable and is musically accurate over four octaves or so. Here's an example of a track produced with it. Apologies to JS Bach.

My current modular project is building one of Ray Wilson's Sound Lab Ultimate and the Ultimate Expander.  These will go in a cabinet that's the same size as my existing modular and should supplement it quite well. This time I actually bought the PCBs and faceplates and it has made the whole thing a lot easier. I have the PCB populated and all the intra-faceplate wiring done and I'm beginning working on the board to faceplate wiring. Trying to keep it as neat as possible.

While I enjoy working on the modular systems and will likely eventually expand to a third cabinet, I had a desire for something a bit more portable. Plus, especially since I don't do a lot of coding now in my day job, I like the idea of a project with a programming component.  I enjoy having two projects on the go at once, it's useful when one gets stuck or just simply when the work is tedious! However I really need to work hard to make sure it's not more than two projects....