I built a commercially available Eurorack module based on that circuit — there are some changes but that was the starting point. Nice thing about it is it has trimmers on each output for calibration, rather than just a fixed gain that’s supposed to be unity. And in fact I intentionally “miscalibrated” one channel on mine to slightly more than unity gain to get around a problem with the Mother-32 control voltage.
If you’re so inclined you could buy the PCB and use it to make a Kosmo module. (But you have to buy the Eurorack panel with it.)
Or you could even buy the kit, but be aware if you do: The PCB allows for either through hole or 1208 SMT resistors and capacitors; the kit comes with SMT resistors and THT capacitors, for some reason. Also it’s missing a few components because SynthCube was working off the BOM for an earlier version. I wasn’t ready for SMT at the time so returned the kit and sourced my own parts.
Pretty sure you could have both a 3.5 and 1/4” wired to each other on the out of the buffered multiple and it would still work as intended unless you pulled a signal from both? I could be off here
No kidding! I’m glad it’s a decent design! I also like the trimmer adjustments and the fact that each out gets independently buffered. Saw some other “buffered multiples“ that seem like they aren’t really buffered.
This was more just a jump off point to learn kicad for me. I think I’m about half way there with probably 12 hours in
Thanks. That makes sense. I built a 1/4" jack patch panel years ago (all switched) and that popped in my head when I saw the pictures. A buffered multiple is much more practical and safer.
The opamp gets its feedback from before the 1k output resistors, so they’ll all see the same voltage. As long as you connect sane devices (i.e relatively high impedance inputs, decent cables) it should be fairly robust.
I think you should wire them in parallel if they’re open jacks, and in series if they’re switching jacks.
The reasoning is that a switching jack will short the other jack it’s in parallel with, which is undesirable behaviour on an output and potentially extremely damaging in an input.
If you’re using open jacks in parallel for an output, they’re basically a passive multiple.
This one’s done, now that I’ve gotten the pot connections the right way around. My first module based on PCBs of my own design, and first PCB front panel.
