Tiny-rack
The green module is an analog voltage controlled oscillator designed around the CEM 3340 chip and the silver module is an analog voltage controlled filter based on the ARP 2600. Both are built on custom designed circuit boards with prototype aluminum panels.
These are both made in the standard eurorack format and adhere to a volt per octave standard. They both use +/-12 volt power supplies and would interface perfectly with any off-the-shelf modules. Designing within the eurorack standard was an intentional constraint, ensuring the modules could integrate seamlessly into existing systems without adaptation or modification.
More broadly, this project represents an arc from a hobbyist following online guides to a circuit designer with a working understanding of electronics and 3D design. It shaped my production pipeline for these kinds of projects and helped refine my understanding of my own production capabilities and the capabilites of fabrication houses overseas.
The whole thing was 3d printed in two parts on my Prusa Mini, which means pretty much any 3d printer could make one of these.
Now I just go from breadboards straight to PCBs, it’s a much more efficient use of time. But I appreciate the simpler times, it taught me a lot about troubleshooting and circuit analysis. It forced me to learn how to read schematics and understand what was actually happening within the circuit.
For a while I would just copy guides and hope they worked, but through projects like these I was able to step up my game and pick up some core skills along the way.
It’s super lush and deep, but controllable. I’ve made a handful of other filters that are much less easy to wrangle and don’t sound nearly as “pro”. (I’ll include a sound sample TBD)
The main downside is that it needed precision polystyrene capacitors. You can see them in the photos, they’re silver and red, and pretty expensive (as far as components go). When I circle back to revisit this project, that’ll be a main issue I want to address. Maybe some supporting circuitry could replace those with more commonplace capacitors. Who knows.
I made this and all of the other modules with through-hole components. This is because it allowed me to assemble the PCBs myself with a normal soldering iron. I’d love to do future versions with surface mount components, it would make the boards smaller and faster to produce, but for now it’s not in the budget.
You can see I ended up sandwiching 3 separate perfboards together to get it all set up. I thought this would be a clever way to isolate parts of the circuit, but it ended up being a nightmare to integrate together. Another learning moment where I was reminded that breadboards are the way to go for something like this.
There is one subtle issue. The whole thing is green! I messed up when I ordered the panel and forgot to take off a default layer of green solder mask. Oops! It looks cool though, but it wasn’t the intention. It is just a prototype at this point and has a few other things worth revising in a future iteration. This was an important mistake to make, as now I have a more thorough checklist before I send off the files to get produced.
Overall, Tiny-rack became less about individual modules and more about understanding how electronic design, physical construction, and manufacturing realities intersect. The project pushed me to think across the entire system. From schematic to PCB, from enclosure to assembly, and clarified the importance of designing instruments that are not only functional, but compatible, buildable, and expressive. While there are clear areas for refinement in future iterations, this project established a workflow and skillset that continues to inform how I approach hardware and electronics.