In case you don't know what Eurorack is, it is a standard of modular synth that is now the most popular. The height of the modules are a fixed amount of a little over 5 inches and is measured units. Standard modules are 3u. The width is measured in horizontal pitch or hp. One hp is about .2". The depth varies quite a bit depending on the design of the module itself. Power for the modules is provided via ribbon cables that deliver +12v, -12v, and +5v. Modules use (or don't use) any or all 3 voltages; again it depends on the module.
I started considering a Eurorack myself mostly because of all the crazy cool modules that were constantly being released. There are a ton of module manufacturers too, so there's basically a module for anything you can think of. My original plan was to buy a starter system, such as the Pittsburgh Modular Foundation 3.1+ (see below). It gives you all the synth modules you need to have a subtractive synthesis system with a few extras. The plus part of it is that it has a whole empty section to add more. This is pretty pricey to get all at once so I started considering building it a bit at a time. So that's what I did.
I decided to build my case since I like doing that sort of thing. Like you'd expect, there are tons of really cool, useful, and bizarre cases out there. So I started looking for images I liked to help my decisions. At this point I found it very useful to save all of my research somewhere as I went. I used Pinterest to do this, but there are a million other ways you can too. Using Pinterest is helpful in the sense that you can access it from anywhere and give and get more ideas from other users. Here is a link to my Eurorack board:
https://www.pinterest.com/fishman77/eurorack-ideas/
I ended up deciding to make a suitcase-style portable case with 9u of 104 hp each. I wanted to have plenty of room to grow and not have to build another one right away. I found deciding the depth of the case to be rather tricky. It's possible to make very shallow cases, but that limits what you can put in it. I ended up using 1x6 boards for the frame so the internal depth is around 5.5".
Deciding what power supply to use also had to be an early decision. I ended up choosing the TipTop Audio Zeus Studio Bus (see below). I wanted something that could handle most anything and had plenty of amperage. The Zeus Studio Bus is powered by an external power supply through a module that has a power switch and input for the supply. You can chain 3 Studio Buses off of one power supply. So that's also what made me decide on 3 rows for sure.
There are quite a few places to get the Eurorack hardware and rails. The rails are known as vector rails. Some places let you decide how many hp you want and they will cut them to length. I got mine at Thonk, a DIY synth store in the UK. One thing I liked that they offered were aluminum mounting brackets to screw the vector rails into. This made it much simpler to get the height of the pairs of rails exactly right. The other choice to make with vector rails is deciding how to screw the modules onto the rails. You can use sliding nuts or a threaded strip in the rails. I went with the sliding nuts because it lets me put the modules exactly where I want them. Also, I didn't like the idea of potentially stripping out a screw on the threaded strips.
So, vector rails, end brackets, sliding nuts, 2 lengths of screws, circuit board standoffs, and one of the Zeus power boards were all ordered before starting to build the case. Check out the pictures below to see the progression of the case.
In my next post I'll discuss some of my Eurorack modules and how I came to choose them. Thanks for reading! Oh, here is the rack in it's current state:
