When I started building Eurorack modules, I looked into power supplies and in particular looked into building one, but at the time I didn’t find anything DIY I liked at a price much better than the TipTop µZeus. So I bought that, still the only module in my case I bought assembled. And it’s worked fine, no problems right up through my present 84 HP of Eurorack even with only a 1 A wall wart feeding it.
But the sheer number of modules I have connected to it gives me pause and I felt I should give the µZeus some help. These days I know more about where to look and more about what I want, and I decided the DIY Frequency Central FC Power would be suitable for the job. It’s an open board supply, fed by a wall wart, with regulators and filter capacitors and diodes for ±12 V and +5 V, easily capable of handling whatever’s in the case that isn’t on the µZeus.
I bought the board (two actually) from Frequency Central and parts from Tayda. FC also has a couple of other boards: the Microbus is pretty much an FC Power with room for eight 2×8 pin connectors and the Routemaster has footprints for twelve connectors. The FC Power accommodates only one connector, but can be connected to a separate bus board. Of which FC has a couple available.
But the +5 V rail on the µZeus? I’ve never used it. There are very few Eurorack modules around these days that do use it, or the Gate and CV lines. Almost all have 2×5 pin connectors on the board for just ±12 V and Ground. For Kosmo “almost all” becomes “all”. The occasional module that needs +5 V, like the 8 Step Sequencer, gets it from a regulator connected to +12 V. So why bother?
I didn’t. I omitted the +5 V regulator and other parts when I built the FC Power, and for the bus board I used this:
That’s my adaptation of a 12x(2×8) bus board by tomarus. I converted it to 12x(2×5). That makes it smaller in one of its dimensions, with about 40% fewer pins to solder. For now, at least, six connectors are enough, so that’s all I did. I can add more if I need them.
(You need ribbon cables with 2×5 IDC connectors on both ends to connect the modules. The usual synth vendors don’t sell such things, but I’ve learned to make and test my own.)
The FC Power connects to a switch and a 2.1 mm power jack on the side of the case.
The bus board schematics, PCB layout, and Gerber files are in a GitHub repository, if you want your own.