Eurorack: discussion, advice, learning, questions

Hey hey! This is perfect!!! Thanks!

Hi!

For a live performance I would like to play previously composed MIDI clips and control the playhead of them by an LFO or CV instead of a clock signal. This would create a more “human” control effect specially combined with motion capture sensors like the one from Genki Instruments. So by patching a sawtooth signal the 0V will be the starting point of the clip an 5V for example will be the end. I need the playhead move smothly as I said and not by quantized increments. I don’t know if such module even exist …

Another workaround I’ve thought is to use a CV and trigger recorder, and previously convert the MIDI file to a long pairs of samples of the CV and trigger notes. Then use my Befaco VCMC to fire notes converting again CV 2 MIDI. If I use this option I would need at least 8 channel sample player (to play 4 notes polyphony) able to send DC coupled signals and with CV control over the playhead of the sample. I have an ER-301 but this won’t work as the OUT jacks are only for audio signals …

Any idea on what modules could I use for this?

Thanks!

Something close is the “MIDI File Playback (Free Running)” algorithm on the Disting MK4, which basically controls the tempo of the MIDI file playback via CV:

From your description though, it sounds more like you want to ‘scrub’ along the CV output via CV?

Since the Disting is DC-coupled, another option is to convert your MIDI file to a DC-coupled .wav on the computer (ie replace the notes with the appropriate DC-value), and then try the “I-6 Audio Playback with Scrub” algorithm.

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Yes, I guess playing a CV file over a DC coupled interface is the best option. I actually have the ER301 sound computer which allows me to record CV over the different inputs, so I can use the Polyend MIDI 2 CV module to record CV’s … Then I need a DC coupled wav player. Probably eh Disting is the cheapest option, but it only has 2 outputs, right? The Rossum sample player is probably what I need but at a very high cost …

Ive been exploring different ways rythmic/timed events in my modular system. Modulating Zadar’s time of a looping ad envelope has been pretty interesting and given a west-coast vibe. I was using this envelope to trigger other inputs. Are there any cons to using an envelope as a gate/trigger other than hold time? Ive gotten some interesting results this way. Other than using trigs and gates how do you like to create timed ‘events’ in your system?

Edit: typo

Most of my music is pretty traditionally rhythmic (as opposed to ambient and “timeless”), so I mainly use a master clock and then various clock-divider-esque utils. Here’s a typical setup:

  • Hermod as master clock driving Pam’s as my main clock divider
  • Pam’s outs 2-8 are different clock divisions. I typically try to order the outs from fastest to slowest, ranging from like x1 down to /96. Some of them are gates, some of the gates have euclidean patterns applied, and others are LFOs (typically triangle or random)
  • I’ll also mult Pam’s out 1 running at 24ppqn to every other module in my system wanting a clock in (MI Grids, MI Clouds, MI Tides, O&C, Intellijel Steppy)
  • MI Tides and O&C in particular I’m often running in their quad LFO modes
    • for MI Tides: freq. range either in “movements” or “rhythms”, output mode in “different frequencies”, and ramp mode in cyclic bipolar
    • for O&C, I’ll run Quadraturia with a small shape spread (~20-40) and small frequency spread (2/3, 2/5, 1/7)
  • This way all of my main LFOs and modulation triggers (from Pam’s, Tides, and O&C) are cyclic in a way that ties back to the rhythm (in a mix of even and odd/aliasing divisions). I have an øchd for deliberately untimed LFOs, but those aren’t quite as common
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Certain trigger inputs will not alway register inputs that aren’t square on-and-off signals. I’ve found it’s pretty uncommon and not necessarily worth worrying about. If you do come across it, you can just use a comparator.

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Excellent, I have a very similar timing workflow - tempi outs are all clock divisions, with half of them on the mod setting which makes them all switch places every once a while. This keeps the quadraturia LFO’s changing their tempo, but keeping them loosely in synch back to tempi. The rest of tempi’s outs go to other modules wanting clock (or some modulation of), and yes typically multing channel 1 for that same purpose. I really love quadraturia, so ended up getting a 2nd O&C just so I could load hemisphere suite on it without sacrificing quadraturia.

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additionally to what @oot said, if you encounter any problems triggering with envelopes IIRC chaining on Zadar works with looping envelopes too, you could chain another channel so that it gets triggered whenever the first one starts (phase to 0), set it to the square waveform and get a gate this way. you could then modulate the gate width with warp and time params. or increase the phase and get a delayed gate or trigger.

that reminds me i have to start using my Zadar more :<

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Interesting! I have a pretty small system so I dont need to worry about clocking other clock sources. Does the 24ppqn clock signal mean your other clocked modules are running at a much faster rate. Or does the 24ppqn just have a higher fidelity clock signal? I also have a ornament and crime but have never really explored the clocked waves! Sounds interesting to experiment with odd quantized divisions!

Interesting. So would an input that only recognizes a trig reach once it hits its max value instantaneously? I have some options for analogue logic in my Cold mac. If you took a tempo synced lfo >comparator you could have quantized divisions of the clock that could be very cool to experiment with.

24ppqn is the default clock in and out rate on most modules. So yeah they don’t run any faster with 24ppqn in, they just have a higher fidelity clock. Most modules with a clock in describe their expected input rate in their manual if you’re unsure :smile:

I’ve been wanting to make a few midi to CV boxes so I can sequence part of my eurorack setup with my MPC. I came across the following which seems quite promising; https://little-scale.blogspot.com/2019/01/12-gate-16-cv-usb-midi-interface-bom.html

Does anyone have any experiences with this interface? Code seems easy to understand / alter, but wondering about resolution for 1v/oct for example. Secondly, but possibly off-topic, how does one go about ordering PCBs like this? When I check PCB manufacturers I get so many options it’s a tad overwhelming.

Thats a really good idea! I just got my Zadar a few months ago and the possibilities seem like I will be able to explore for a long time. Very deep! The other day I was experimenting with treating envelope signals out as drum-like sounds.

Wow good to know! Do all clock types modulate well with time? That might explain some clock skipping issues I has having with my moog grandmother. Maybe a miss match of clock type.

I’m not an engineer so I can’t really explain exactly how triggers/gates are detected in various modules but I believe some check for variance in level across time, so if the signal rose from 0v to 5v withing 1ms that counts as a trigger. But it’s really all over the place in eurorack when it comes to gates as triggers. There is nothing consistent about what level they are detected at, what level they’re output at and how they’re detected, except per manufacturer, most of the time.

Really my advice is just to keep doing what you’re doing as long as it works and if it doesn’t, use a comparator or perhaps raise the level of the signal (or both).

ppqn is not the only issue. The voltage and length of gates/triggers is an even bigger problem when it comes to mismatches. It’s fairly common in Eurorack to have to use offsets and/or delays to get clocking to work.

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I’m curious about people’s experience with the Tetrapad? How playable is it when using it in voltage fader mode?

I was looking at either a Tetrapad or a Doepfer a-198 to add some more control to my system. The Tetrapad looks pretty flexible but the a-198 looks like it might be more fun to play. I already have Pressure Points and Brains which I really like and plan on keeping but I’m looking for something different to add a different kind of control.

I’m super interested in generative/krell patches at the moment. So there is plenty of info about random pitches and how to make them musical with quantizers and the like, plus love the idea of Turing machines to setup pitch sequences.

Question I’m having at the moment is gates. I definitely want to keep notes playing in time with a clock but would like to have the gates vary in length. Not just divisions of the clock though, but longer gates too. For example, a gate that varies from 16th notes up to a full measure or what have you.

Also, sort of but not really related: if you couldn’t use a built-in EOC output of an envelope (such as not having the option on your module), how else would you arrange to trigger an event based on an envelope finishing?

A comparator will do that.