Eurorack: ask questions here


I want to find some resources on getting a more basic understanding of modular synthesis. Not in the sense of “this is what a VCO is” but knowing how to combine basic components in order to build more complicated circuits. Things like, how to create a phase locked loop using a comparator, slew, and VCO, or this great patch for controlling the probability of random voltages.

While modules that handle this sort of complex circuitry behind a single panel are cool and can save you time, the trade-off is that they tend to give you a much more limited range of control over their behavior. I find it more exciting to see how I can mess around with the different stages of a circuit, and I’m always trying to figure out ways to replicate the behavior of more complicated modules so that I can play more deeply with the concepts behind them. The more I dive in, the more I realize I’d benefit a lot from some proper education on what I’m messing around with. So does anyone have any books or websites or video series’ you’d recommend for learning more about this?


Gordon Reid’s 63 part ‘Synth Secrets’ is always a good place to start. He begins with the basics, but goes into more advanced areas as the series progresses.“Synth%20Secrets”?solrsort=ds_created%20asc&f[0]=im_field_subject%3A8106


Maybe Navs?

I hope that someday there will be a sequel to “Patch & Tweak” which goes into that level of things. Sort of the Allen Strange of the Eurorack era.


If you can find block diagrams for the modules you want to try emulating they will give you a good idea how to go about it.


Thanks for the tips, y’all.

I’ve read through maybe half of the Synth Secrets articles and they are indeed great, learn something new each time. I hadn’t really looked into Navs’ site, beyond some of his module demos but it looks like there’s some good stuff in there! And great idea to check out module block diagrams. I’ve been relying on block diagrams on wikipedia when I’m curious about a particular concept but hadn’t though to actually look at module charts before.


Batumi question/issue: mode selection on powering my system is inconsistent. I usually use quad mode, so when powering off my system, this is the last active mode; however, sometimes the unit starts on phase instead (about half of the time)

Did I do something to cause this behavior?

I’m running expert firmware (not the version with random waveforms).


Yeah that happens with some power supplies due to the way it boots up. With me it was a Pittsburgh Structure 208 case. Did not happen with an intellijel power supply. Some digital modules are picky about the power on the +12 and -12 rails.


That makes sense, I noticed it after switching to Trogotronic. Guess checking the mode will just need to be part of my start up procedure :frowning:



has anyone used an arturia keystep as a midi controller in conjunction with ansible’s midi modes? i just got an ansible and don’t yet have a grid - my plan was to use it as a TT expander while my bank account prepares for a grid, but @zanderraymond mentioned that ansible can also be used as a midi host. after reading the manual, i’m wondering what kinds of conversations keystep and ansible can have. a few questions:

  • did you use mini USB to USB or MIDI to USB to connect them?
  • did you have to power keystep with a separate 9v power supply if you connect to ansible with the mini USB out?
  • which ansible midi allocation styles have you used? keystep already has an arpeggiator on-board; i’m curious about poly mode.


I just tested this: My Make Noise skiff can power my Keystep via Ansible with the Keystep’s usual USB out. I’m not gonna play around with it at the moment, so I don’t know if you get noise this way. Visually, the 4-voice round-robin poly mode appears to work fine.


It all works. Usb powered straight through ansible. Poly works perfectly too.

Just got to get those 4 sound sources. :slight_smile:


My Batumi in a Trogotronic case doesn’t have any issues…


Was thinking about making custom panels for some of my eurorack modules using laser engraving laminate plastic (the colours!). I feel like I haven’t seen that material used very much for this purpose, they are usually aluminum. Is that because of a grounding thing? Do I increase the risk of hum if I use a plastic for panels?


I think a big factor is that you need much thicker plastic to be strong enough, something like 3mm. this doesn’t work with every type of button/switch very well.

I’ve had a few acrylic or similar panels on DIY modules and didn’t personally care for the added thickness or the look, but those are subjective!


Good point. I took a closer look at some random things I have around the house that is made with that stuff and they’re not very stiff, very bendy.


Sorry for the delay (I didn’t see your answers until today…)

I purchased a new module, the Tangle Quartet, so right now I have the following modules:

  1. Grendel DC-2e Drone Commander 2 Eurorack + Expander
  2. Pamela’s New Workout
  3. Tangle Quartet

I’m going to try to ask more specific questions.

I’m being able to send envelopes from Pamela’s New Workout to Tangle Quartet in order to control Drone Commander’s volume, but only at regular intervals. Is it possible (with my current setup) to generate envelopes at irregular intervals (four quarter notes and one whole note, for example, or eight eighth notes and two half notes)?




Ah! Here comes the fun of cv and vcas and gates. Or pams can do some of this for you too with some creative self patching.

You could for instance use two channels of your vca and the mix output to mix and modulate cv signals patched back into the cv input of a third channel which will pass audio.

You could also use one channel of pams to modulate the clock division of a second via some menu dividing and patching one channel’s out into a cv input on pams. The second channel could then be used to open a vca, filter, etc.

I am away from my system, so i can’t remember the encoder combo process for pams to set that up off the top of my head.

There are some great videos on the bastl YouTube called Pachens Nicol. If i remember correctly there is one that demos cv mixing with vcas. Either way, certainly wirth a look, they’re well produced, direct and very informative!


Thanks! I will try to mix cv signals and I will try self patching on Pams…


With Pam’s, you could do any of the following:

  1. Modulate divisions of a given channel, as @coreyr said, from another Pam’s channel
  2. Use output ‘shuffling’ (I forget exactly what Pam’s calls it), so that the output of 1 moves to 2, 2 to 3, 3 to 4, 4 to 1) to be sending different divisions to your VCA.
  3. Use the Euclidian patterns feature to get rhythms that are more ‘musical’.
  4. Manually manipulate the divisions in real time, either via Pam’s encoder or by sending CV out from an unused channel of Tangle Quartet (if Tangle Quartet outputs CV from unused channels; if not, you probably will want an attenuverter like Shades or Triatt or O/A/x2 or a dozen others before too long; most attenuverters do output CV in the absence of an input signal). Despite the menu diving nature of Pam’s I find it reasonably playable in real time, and sending in CV from elsewhere would give you multiple manual controls.

What Pam’s doesn’t let you do is specifically say “I want a quarter note, then two eighth notes, then two quarter notes, then a quarter note rest, then two quarter notes, then a quarter note rest.” In general modular sequencing is not very strong at intentional through composing. It’s strengths are more in using and abusing simple building blocks to create emergent patterns and happy accidents. MIDI to CV converters are good for more lengthy intentional patterns created elsewhere.


Wow, thanks for the detailed responses, guys!