Yes? No? Maybe? Module // Probabilistic gates

DIY STUFF
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Yoooo.

So, this is something I created and built few months ago. I wanted to make a video about it but I’m super lazy/busy, so here’s some very nice pictures.

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It’s what we can call a “Probabilistic Gates” module. You have 1 Gate in and 5 Gate out. Each output has its own chance of apparition.
If the knob is down to 0, then the gate will never be reproduced. If it’s at 1, it will always be reproduced.
If it’s at the middle, then you have 50% of chance that the gate will be reproduced … pretty clear, right?

It’s based on a Arduino Nano and some op amp. Really cheap and simple. And super fun to use if you like to do some “generative music” … like you will never really know what’s gonna happening …

Here’s the schematic :stuck_out_tongue:

Yes_-No_-Maybe_-1024x571
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The coooode : GitHub - alexiszbik/yesnomaybe: Arduino based random trigger for modular synthesizers

Wants to know more (actually I said everything I could … but yeah … ) : Yes? No? Maybe? – YMNK

AGAIN, I’m not a super expert in electronic (but I’m good with code, heh) so, if you have any remarks or suggestions about how to optimize this thing, I will be very happy to hear it.

Thanks!

14 Likes
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Once I got past the transparent background on your schematic which makes it harder to read against a dark background (this works better for me) I think it looks good — the one thing I’d change is to add 1k resistors in series on the outputs.

The LEDs don’t have to take up Arduino pins, they could be driven by the same op amps as the outputs (with a larger resistor!) but since you’re not using those pins for anything, no harm done.

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Thank you for your feedback @analogoutput !
Yeah, I did the schematic on Google Draw, didn’t verify it was with a transparent background, sorry!

Yeah actually, we could make the LEDs driven by the output and add 2 mores possible output! Might be a nice update.

Ok, noted for the 1k resistors. Thanks again!

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The design looks pretty solid, good job!

I do think you missed one major opportunity here: make it voltage-controlled! A few rail-to-rail opamps (eg MCP600x) should be able to take care of that. You can even get away with just one opamp per channel. (Sum the CV and manual inputs, re-invert them in the firmware.)

Cheers

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Neat! Seems a bit like a cross between branches and a sequential switch.

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Hi Everyone,
I’ve added an update to this project, with a pattern switch.
This will transform the behaviour of the module from a random trigger to a pattern sequencer.
Each knob of each output will choose between 62 different patterns (from 2 to 8 steps length).
This is very useful to create some polyrhythmic madness !

Here is the new schematic :

2500×1397 352 KB

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You shouldn’t leave the inputs of the second opamp in the '072 floating, that’s bad…

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I trully didn’t know that was problematic, but I take the advice.
I use to let floating pins all around, so I will take special care now.
I assume you have to wire all of them on the ground.
Thanks

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Check How to Properly Configure Unused Operational Amplifiers (Rev. A)

Have a look at Figure 3. Proper Implementation of Unused Op
Amps - Split Supply Rail

Basically tie the non-inverting input to ground and connect the output to the inverting input.

Cheers

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Great, thank you very much !

1 Like