Row of 1U Eurorack modules including nupsi

A while ago I started to build a little Eurorack to extend my beloved Moog Grandmother. Most of my modules are DIY kits and I quickly noticed that building my Eurorack is at least as much fun as actually making music with it.

Some time ago, for a patch idea I wanted to do, I needed the possibility to add two voltages more or less precise. I was not happy with the stuff I had (Eurorack Disease). So, I took my breadboard. After some web search-assisted remembering of what I learned about electronics many years ago and an extremly professional circuit drawing, I had my first way too big nupsi prototype.
To fit it into the last 4HP of my 1U utility row, I designed PCBs. Then I noticed that it is not completely insignificant to think about orientation while designing interconnected PCBs. So, I designed PCBs again (which is surprisingly cheap!). This is how I created my first Eurorack module. Its not very complicated, innovative or crazy, but it’s cute and small.

So why am I telling you all of this? Because don’t be scared to try stuff out. It is fun to create something and I forgot how good it feels. Go for it.

What nupsi does

This is not too hard to describe. It simply adds two voltages, positive or negative. This could be control voltages (CV) like for instance adding a static offset from a voltage source to an 1 volt per octave CV signal. It is build of a TL072 OpAmp, so it’s fast enough to use nupsi as a simple audio mixer by just plugging in two audio signals.

But it’s main feature is it’s small format, because it fits exactly in this annoying 4HP gap in my 1U row for which no useful modules seem to exist. Coincidence? I think not!

Back side fo the nupsi module

Want one yourself?

If you want your own little nupsi, drop me a mail, currently I have some spare PCBs, which I can send you. The build is fairly easy. It is just a few parts, but some of them are SMD, so you should have soldered before. I would say, nupsi is a perfect first try SMD project. ;)

The front panel is made of a peace of plastic I had laying around and some paint. You would have to make your own.

nupsi is not openly listed, but via this link you can find it on ModularGrid.

26 May 2021