I’m looking to add some drums to my Kosmo! I would like to have a kick, snare, hats, and a crash as I mostly do synthpunkish type stuff.
What are some of your favorite drums that may be available as a PCB? I’m a big fan of the more “real” sounding drums, like the 909, Linndrum etc
I am in the process of making a drum modules. 2 kicks, 2 snares and 2 hi hats. I have been doing lots of readings and, for me, the circuits are often extremely complex for “just” a sound. So i decided to go the easy route, with Moritz Klein kick, 808 snare from soundforce, and I’ll be doing hi hats with resonnant lpf and hpf.
This is a great construction guide with some education about the circuit and how to make it for a dual supply system or single power supply. Also, if you make the circuit for dual supply you free up an opamp on the lm358 (or tlo72 and the like) conveniently for adding a slightly modified duplicate circuit making a higher pitched tom (lower the values of the caps in the t notch) to make a dual module. Kick and tom. 
This one is a bit more complicated but super fun to use.
Super simple without the vactrols, but they aren’t hard to add. Just not as simple. I don’t find much use for the vactrol on my snare but I use it a lot for the hat. I realize none of these are PCB modules, I guess I missed that part. Oh well, they are fun to do on strip board, and you can definitely make them Kosmo format!
I use the Barton Analog Drum. I have four of them mounted in one panel.
I also like https://prok.co.uk/ drums! That is eurorack format, but it is easy to adapt to kosmo 
it’s digital but that has the advantage that you can turn it from kick to clap to snare etc. by just changing firmware!
I’m a big fan of the Skull & Circuits Metal-o-tron II:
Skull & Circuits Metal-o-tron II
It’s an impressive metallic percussion generator that can do hats, cymbals, and the like, along with many more experimental sounds. It might be overkill, but it’s fun! You can pick up PCBs from the website, but they’re in eurorack format and may require a bit of additional wiring/etc. to fit it onto a Kosmo panel.
However, since the schematics are published online, I was able to convert it into a Kosmo format module and it works great:
If I ever get around to learning how to use git/github, I’ll upload the files & gerbers for anyone that wants to make their own. 
But, builder beware: this one has a high part count!
Oh, nice. I would love to build one of these. I am interested in those files, or if you have any extra pcb sets to sell/trade.
Me too. Percussion is at the top of my to do list.
Maybe I should do a git tutorial.
Added:
I’ve been looking at the Metal-o-tron for cymbal sounds also. I just got the Behringer 808 clone, and the only downside to the 808 over the 909 is the way the analog cymbals sound. The schematic is… a little intimidating, but it’s good to know that they sell the boards for it! Thanks!
I been looking at this circuit today for the first time. I have some lm13700 sitting around waiting for this type of thing. I’m gonna breadboard this for sure.
this is a second on the Barton Analog Circuits drums . simple design , easy to build , relatively cheap and they sound good .
I built one in Eurorack back in the day and I’m planning on something like it in Kosmo soon — by which I mean I have a first draft in KiCad for something that started as the Analog Drum and then went off the deep end… I’ll do that if it gets past the breadboard tests. Or just fall back on the original circuit if it doesn’t.
Also looking into the Thomas Henry Bass++ and the Ken Stone Cynare, and I have a couple NLC Bong0 PCBs to stuff one of these days.
I had to look up the Thomas Henry bass++. I’ve always wanted to build a Thomas Henry circuit. Mainly the 555 and 4046 vco, but they’re a little out of my depth. I think I can handle this one. It looks a lot like the Barton analog drum mentioned earlier, and I’m definitely going to breadboard both.
Yes, they’re similar. Biggest differences are the Henry has a section to add impact noise, and the Barton has separate envelopes for the pitch and amplitude. But there are published mods for the Henry including a second envelope.
It’s pretty remarkable what Henry squeezed out of only two chips (and a few transistors).
No doubt. Very appealing to a diyer electronics beginner like me for sure. I get anxiety trying to build the vcos. There is just so much going on with the schematics I get stressed just looking at them sometimes. This one (bass++) is very pleaseing to look at, though. Elegant, indeed.
I suppose I should mention this module some idiot threw together.
I built this twice on breadboard without success. 
the pcb’s are pretty affordable through the synthcube site or Barton’s .
