Eurorack: ask questions here (archive)

Use it like an FM Aid. Take two saw triangle waves, call one the “modulator” and run it through a VCA, mix it with the “carrier” and feed the mix into the wavefolder.


Which logic modules are people using? I have an Erica Pico Logic but I’m not so into the scrolling through logic types with button presses, and I’d like more inputs.


I have the Ladik Bool2. The Bool3 has three inputs.

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For boolean logic, hard to top the Klavis Logica XT. It’s cheap, compact, and does loads of interesting stuff.

Do you have a link to a good explanation of logic modules?


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Sure. Note that there are two kinds of logic modules: ones that compare gates and ones that compare voltage levels. Some people refer to the former as digital or binary logic because everything they do pertains to creating two states (on or off), and they’re typically used to process gates and triggers, derive rhythms, and create logical patch programming (if this, then that). The latter are often called “analog logic” because they compare voltage levels (presumably one or two are fluctuating) and favor one over the other depending on which is higher or lower; these are used to process audio (or cv). Sitting between these two are comparators, which look at fluctuating voltages and generate binary states from them.

These are in no particular order—watching several of them should get you going.


I use omiindustriies’ Illyana!
The selectable logic section is great!


Fantastic! Thanks so much!

I have an ARC artificial neural network. It can be patced for many logic duties. Used to have the Doepfer dual logic which was also great.


I also was not a fan of needing to page through the various functions on the Pico Logic so I ended up removing it from my case. Right now the only module I have with explicit logic functions is a Mutable Kinks which includes a Min/AND and a Max/OR in addition to a few other utility functions. That, combined with a Maths, a WMD/SSF SPO, and a VCA lets allows me to patch up any logic function I need in a particular moment:
You can use pretty much any DC coupled VCA for AND. Just patch one gate to the CV input and another to the Signal Input. You should only get a high signal out when both inputs are high.

OR can be achieved with any module that provides DC coupled mixing. Just mix the gates and then you will get a high signal when either input is high.

You can get an XOR by inverting an AND and summing it with an OR.

You can do the voltage mirroring trick to get the NOT version of any of the above functions (NAND, NOR, XNOR). Just take a gate, invert it, and add a large enough offset to get a mirrored version. You can also run a gate into channel 4 of a Maths and take the EOC output to get the NOT version of that gate.


I wish these were still in production and that I wanted one enough to make space:


When I was starting to find out about eurorack, I found this module very alluring. Never had one though.

Use a vca before the wavefolder. The input level makes a huge difference in most wavefolders so modulating the amplitude of your signal before it hits the wavefolder is a great way to find different timbres.

If you have a crossfader (or enough vca’s to patch one up) try using an envelope to crossfade between the original signal and the folded wave. This can give sounds reminiscent of a low pass filter sweep but with more variation. The overall sound of the Make Noise 0-Coast is largely based on this wavefolder and fundamental crossfade trick. Also try using a random source or sample and hold to modulate the fold amount for every new gate signal as a variation on the crossfader patch.

Instead of a sine or triange wave, try using a low pass filtered saw wave as your input source. Small adjustments to the frequency of the lpf will cause large changes in the wavefolded signal.


Apropos of nothing, just pointing out that “Little Modular” did an overview video of the new Klavis Quadigy Quad Programmable Envelope Generator a few weeks ago:

… and last night, I posted an in-depth video about the same module, but focusing entirely on using it as an expressive ADSR:

I presume the former video was paid commercial work; mine was definitely not. As usual, mine is obsessively (excessively?) detail-oriented. I still managed a few mistakes, which I’ve documented in the expanded video description on YouTube.


Question re: 4ms Quad LFO: Can it be used as a pingable AR?

Great album title…

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so the One-shot mode, where the Reset jack can be used to trigger a one-shot envelope if the external ping clock is stopped, is not going to do that?
i.e. not using the ins, but triggering the resets

Looks like i was wrong. It had been a couple years since I had one and never used it that way. Seems like you’ve read the manual, no reason why it wouldn’t work…

If that is the case (quad LFO usable as quad AR when pinging the reset buttons), am I right to assume the 8-pin header labeled “PING” that connects a QCD to the quad LFO cannot be set to “ping” the resets? Anyone currently using the module can chime in?

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