Lately I’ve been building mostly Kosmo format modules, which use a power setup similar to Eurorack, but with no 5 V rail or CV and Gate distribution. Then again, nearly all modern Eurorack modules forego the 5 V rail and CV and Gate distribution. They, like Kosmo modules, therefore are designed with 10 pin (2×5) power connectors. Still, Eurorack power supply bus boards almost always have 16 pin (2×8) headers.
I have a Eurorack power supply that yields 5 V, with flying buses having 16 pin headers — and I’ve never needed more than 10 pins, but if I ever find myself needing 16, I’m set. But for most of my setup, bus boards with more than 10 pins would be more tedious to build and would take up more room than necessary.
So I use these bus boards. They have 12 2×5 connectors.
And not much else. There is a terminal block to connect power, and there are LEDs to indicate power on both rails.
(And no capacitors. I have yet to see any explanation of why capacitors on a bus board would do any good, or even any justification of the claim that “well, they can’t hurt”.)
Based on a 16 pin design by tomarus.