Introduction
Music has been an interest of mine for quite a while now. I enjoy exploring different genres as a listener and I’ve also been learning a bit of piano and guitar for a while.
Especially synthesizers have been fascinating to me, even though they weren’t a part of the music that I was listening to for a long time. But there are so many of them with different architectures and therefore different sounds. So combine decision paralysis with my soft spot for systems. Enter: Eurorack. A standard for modular synthesizers.
Eurorack is a nice synthesis1 of a few of my interests: It is a deep dive into synthesizers, a playground for sound design, and the resulting synthesizer is quite malleable. It’s also a way to gain some experience in analog circuit design as well as DSP.
I’ve been eyeing Eurorack for a while but I was put off by the cost of entry. The final push that made me decide to build my own hardware synth came in a course where we built an enclosure together with a power supply and a simple mixer2. While I was taken the first hurdles there, I also got the opportunity to play around on a bigger Eurorack system. This made me realize that real hardware just feels different compared to software emulations, I feel somehow more connected to the instrument. Since then, I wanted to have my own hardware :) .
Here is what I have at this point:
- a case for my synth with a power supply
- a simple mixer module
- a simple multiplexer module
- an Arturia Beatstep Pro
I – quite ambitiously – purchased the Beatstep Pro so that I have a decent sequencer right from the start. One of my realizations during my time with the hardware was that a good sequencer can make a big difference in how much fun I have with such a system. But my purchase was a bit hasty, to be honest. I’ll be building a lot of modules anyways and the Beatstep Pro can replace a few modules, making things a bit easier – especially in the beginning.
Why hardware instead of software simulations?
VCV Rack is an awesome simulation of a Eurorack system. It is amazing how much you can get there even for free. I’ve spent some time with it and while it added to my fascination with Eurorack, I couldn’t really warm up to it. Me not finding a sequencer that I clicked with might have been one of the reasons – I’m coming from the MIDI world, sorry. But using knobs and cables with the mouse feels tedious compared to hardware knobs. And mapping virtual knobs onto MIDI controllers takes a lot of flexibility and clarity out of an already complicated system.
In addition, a lot of my hobbies already revolve around the computer, and I’m currently trying to add more things to my life that do not require me to stare at a computer screen.
Why am I trying to build as much myself as I can?
Another reason for me to go hardware is that I’m interested in the electronics that power a synthesizer. I like the idea of building a synth with my hands while understanding how it works. I’ve taken on software projects for the most part in the past, so the prospect of having the result in my hands is also a refreshing change.
I also want to improve my skills in electrical engineering and a lot of smaller projects (resulting in a small feedback loop) seem to be a perfect fit. And these smaller projects also contribute to a bigger system that has a real use to me – at least that’s my current vision.
All in all, it’s a surprisingly good combination of my interests.
Ready-to-use modules are also expensive. Even kits can run you a couple hundred bucks. That probably has its reasons though. I haven’t seen a breakdown of the financial side of selling Eurorack modules, yet (although that would be really interesting). But I can see how small number of sales can lead to these prices. Especially when development costs have to be allocated.
My first modules
I plan to start with two modules and to plan from there. This way, I can apply the – probably many – lessons to the next modules and the project scope remains manageable.
The first module: a VCO
Every synthesizer needs something that produces sound. While other components can also oscillate, a voltage-controlled oscillator is designed for that job. A VCO does not seem to be the easiest project to start but I have some experience with electronics, so I feel confident that I can at least make something that produces sounds.
The plan is not to do something fancy, just an analog oscillator with the usual basic waveforms (sine, square, triangle and saw).
The second module: a breadboard breakout
My second module will make prototyping on a breadboard easier. I don’t want to have loose components like jacks or potentiometers scattered around my bench when I’m trying out new ideas. My solution is a module that has a few jacks, potentiometers, and switches that are connected to female pin headers which in turn can be used to connect jumper cables from a breadboard. And while I’m at it, it should also allow powering the breadboard as I don’t currently own a dual power supply. This module should be simple enough to include here and it makes life easier for future modules.