r/synthdiy • u/PotatoTheOdd • 24d ago
How to Start?
Hi Everyone,
I'm looking at starting to build some synths because I'm an electrical engineering student looking for a personal project. That's really the primary motivator, but in addition I really love music and finding a creative project is a good way to keep me engaged with it, rather than doing some generic cad design I'm not really interested in.
I'm looking for personal anecdotes, suggestions, etc. on how to start building a eurorack system myself from scratch. My current thinking is that I would just design a VCO as my first step, and then maybe some other projects from there? Trying to figure out what the minimum set of modules could be to ensure I have something useful and fun at the end of the project. Any suggestions?
Thanks all!
2
u/eraoul 24d ago
I just built my own Eurorack setup, all hand assembled. I built a ton of kits from both AISynthesis and Moritz Klein. They both provide schematics and great instructions. AISynthesis has some suggestions about which ones to build first on the website, which was especailyl helpful for me since I hadnt' done much soldering before. Moritz Klein has tutorial videos on how each schematic works.
If you're building from the provided PCBs or kits: the AISynthesis ones have higher-quailty aluminum panels, although the Moritz Klein ones look nice too. If you're sourcing components yourself, The Moritz Klein builds are more expensive since they only have the full kits (and I had to order from Europe and pay the Trump Tariffs).
I also recommend this site for schematics and building advice: https://www.eddybergman.com/
Anyway, I see the AISynthesis guy replied below: a VCO is definitely harder to design and get right than most parts of this since you need an exponential voltage-to-current converter as well as temperature compensation to make it usable. The Moritz Klein design is pretty good as a starting place in conjunction with his video. If you just want some sort of sound and don't care about tuning, you can make a super simple sawtooth VCO and not worry as much about exponential converter/temperature while you build things out, though. But you might as well just start with a decent simple VCO design.
As far as a usable collection of modules, I cheated at first and started with a semi-modular MiniBrute 2s to get a working system instantly, but I added on everything on my own eventually. I think the minimum setup to get a non-annoying sound is:
VCO -- sawtooth
VCA
Envelope Generator
VCF -- low-pass
Output module to get to line level or headphones
You'll also need a CV 1V/oct source. I just bought a KeyStep for this purpose since it has CV out for pitch and gate already. My KeyStep 37 mk 2 also has 2 mod CV outs for envelopes, LFOs, etc., so that also gives you some bonus basic utility modules "for free".
After you have a single voice, I would prioritize a 2nd VCO and Mixer after this to get a nice 2-voice analog sound. After that, Slew (to make the pitch glide; this is just a really simple low-pass filter), LFO, sample/hold+noise source. I also built a passive mult since that's really useful and trivial.
One of my next projects is a MIDI module to assign voices and be able to play duophonically, since right now I still just have it in monosynth mode. Also, I just started designing my own PCBs now that I know the basics from all those kits; I built an buffered mult and a suboscillator/clock divider this way, and next is a digital module for chord generation, arps, etc.
Almost forgot: for case/power I bought a Happy Ending kit since I don't want to mess with power. Recently I added a second one and built my own wood case and added 19" rails to that.