VCF-1 – Vactrols

I’ve been asked if I could do a workshop about synth building. While there are no solid plans to do so yet, I was thinking about what to build during such a workshop. It would be cool to have something to take home you’ve build yourself during the workshop, and even better if it was actually useful. While I was thinking more along the way of simple CMOS based noise-making machines, I was asked whether a filter would be possible. People like filters and if it could be CV controlled, it could be useful even for more advanced synth enthousiasts.

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Percussion – Metal-o-tron

This one is a re-build of one of my first ‘designs’, if you can call them that way. Nevertheless, It’s a percussive module designed for all kinds of metallic sounds; cymbals, hihats, gong, bells, plate hits, cowbells, trash cans, … you name it. Since I’ve build the first one I’ve been using it in every song since. It’s actually a very useful and versatile percussion module. At that time however I didn’t really had the habit of writing down schematics, I just soldered things together until it worked. Yet I wanted to revisit this module again because I could use a second one and I also wanted to iron out some of the quirks my initial build had as well as add a few features I regret not having on the first module. So I kinda started over, this time taking notes though.

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It was totally unintentional, but in the mess of old broken gear I stumbled upon the remains of my very first guitar amp. It was a Hohner SP55 I bought 2nd hand somewhere in the 90ties. A pretty unremarkable transistor based amp which never really tickled my pickle so to say, and on a day I fried the output amp and it ended on the pile of discarded gear. It had a useful reverb though so I scavenge the springs out of this thing and see if I could make myself a nice spring reverb for use in the studio and/or modular.

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Power supply

I’m slowly working towards a project, it’s still not ready to be disclosed though, but it needed a dual rail power supply. I’ve always bought Doepfer DIY kits for my Eurorack needs, but I needed a +14V/-14V for this project. Since I could use an extra +12V/-12V supply as well for future Eurorack work, I decided to build a power supply with variable voltage regulators so it could handle both.

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I found myself short of an ADSR in my system and it annoyed me to no end I hadn’t thought of buying a few more. Instead of hitting the favourite Eurorack module dealer for my fix I went googling to see if I could cook up one of my own. Couldn’t be that difficult. Right. Turns out, there are tons of useful ADSR schematics floating around on the internet. Continue reading “ADSR”