A Polyphonic Experiment

During one Jamuary patch, I had the pleasure of using the Alexandernaut Fugue Machine Midi sequencer extraordinaire. I enjoyed it so much that I sought a MIDI > CV converter so that I could bring that particular brand of magic into my synth. Sequencing is easily the most challenging part of eurorack for me. I’m quickly learning that, at least in the immediate term, “battleship” sequencers and me don’t work well together. The options are oftentimes overwhelming and programming them can be a constant exercise in frustration. When you’re trying to play a polyphonic patch, these frustrations compound as the patch gets more and more complex. Of the large sequencers I’ve used René v2 is easily my favorite. I find it to be the most intuitive sequencer I’ve used. The sequencer in the Doboz T12 is also easy to catch on, and the Verbos Voltage Multistage is ultra-simple. But I’ve done nothing but get my teeth kicked in by some of my larger sequencers. Frap Tools USTA, Oxi One, and 4ms Catalyst Sequencer in particular. Perhaps it’s the lack of effort with learning them, or that I simply quit on them too quickly, but nothing kills a moment like manual digging in the midst of a patch. Fugue Machine, even if it’s walled in its own very small box, is but one of many tools that make sequencing much less of a chore, and can help spark the creative drive to explore more advanced sequencing. Fortunately, there are good ways of leveraging MIDI tools in Eurorack.

I searched for a couple of weeks for my ideal MIDI > CV converter. My main consideration was for sequencing polyphonic patches, so it needed to have at least four channels of pitch CV, gates, and velocity. There are several options. One of the more compelling options is the Der Mann Mitt Der Maschine DROID. It’s a CV generating and processing powerhouse that can do almost anything that can be done with CV, including MIDI > CV conversion. I even have a DROID, and it has a killer feature set. If you can program it. It turns out that I can program DROID. It’s not terribly hard, even if I still do it by hand rather than using the GUI tool to create patches. But DROID would take more space, and would only be useful in this capacity, needing all eight CV outputs for pitch and velocity CV. So I kept searching, and finally settled on the relatively new Befaco MIDI Thing V2. I already have and use the Befaco CV Thing CV > MIDI converter and find it good at its job, even if the screen is not fit for middle-aged eyes. It’s only 6hp, and can sit right next to the CV Thing.

One of the MIDI Thing’s features is that it has 12 outputs. Exactly enough for four voices worth of outputs, and what’s more is that the exact configuration for my initial intentions with MIDI > CV conversion is already saved as a preset, or Pre-Def in Befaco-speak, for quick and easy input and output configuration. I simply set the MIDI Thing to “Predef 2: Multi Timbric” in the Global Menu and it automatically set the incoming MIDI channels to 1-4 and preconfigured the outputs. Pretty slick. Since I was already in for a lot of patching, I opted to forego using the velocity outputs. That wasn’t a step I was terribly interested in today. I wanted pitch CV and gates to trigger envelopes, and by golly that’s what I got after spending less than one minute in the MIDI Thing configuration screen.1

Once I had my MIDI routed in the AUM MIDI Matrix, and properly set MIDI ”Predef-ed” in the MIDI Thing, I fired up Fugue Machine. Since I was testing the functionality of the MIDI Thing and how that would work with a modular system, I wasn’t overly worried with an elaborate, or even original, sequence, and just used one of the included presets. Although I had played with the sequence length and transposition while running through the patch before recording it (which was all supremely cool), I simply forgot when I improvised the recording. I was more preoccupied with timing each channel, the levels of each oscillator, and crossfading the ending. As a result, this recording is a repetitive sequence. It doesn’t repeat exactly because of the modulation, but there’s no variation in anything other than oscillator timbre.

For oscillators I chose the always excellent Synthesis Technology E370, with a User-Loaded Wavetable titled NOV that was left from a previous owner. Thanks, dude. It’s pretty outstanding. Tuning each oscillator to unison (in Morph X/Y mode), I ran each of the pitch outputs from the MIDI Thing to the v/oct inputs. I followed that up by using the eight outputs of the Nonlinearcircuits Frisson to modulate both the X and Y parameters of each wavetable for all four oscillators. This constant timbre changing caused by the modulation also causes dramatic volume changes as waves morph in and out of more and less prominent waveforms in the table. I initially wanted something glitchy, and turned Glitch on HIGH with Interpolation Off for each of the four channels, and while it was cool, it didn’t fit at all in with the overall tenor of the sequence itself. The tonality is too “positive”, being in the key of A Lydian, and the sequence too upbeat. I suspect it would work fantastically on slower, more drone-ish material.

After I routed the pitch CV and modulation, I ran the gates to two Frap Tools Falistris for some enveloping. In addition to being enveloped at the Control inputs, three of the four gate outputs were also multed to the Hit input on one of two Rabid Elephant Natural Gates to provide some beautiful pinging of these ever-changing tones coming from the E370. All four channels were processed through Natural Gate, but only three were pinged. The bass note was only enveloped. In this process I made a grievous oversight. While Falistri is a perfectly good tool for this job, particularly the pluckier notes, more defined shaping with a ADSR would have really served the slower voices well. It so happens that I have perhaps the most advanced ADSR generator in Eurorack, but I didn’t even think to use it, and when I did, I was way too deep in the patch to re-patch and reconfigure the envelopes, so I let it go.

To be honest, I was expecting hurdles to cross, but I was surprised when it all just worked. CV did what it’s supposed to do. Gates did what they were supposed to do. Everything was perfectly in tune and on time.

Once the notes were created in their respective Natural Gate, all four outputs went to the ST Modular Sum Mix & Pan. While three of the four channels were panned to mono, the fastest moving and highest pitched voice was being slowly panned in the stereo field. The stereo output was then routed to the Addac814 6×6 Stereo Matrix Mixer, and sent to the Venus Instruments Veno-Echo. To ensure a solid clock for the delay, I used the now-defunct (or at least unavailable in the United States according to the App Store – which would seem weird) CoVariant Clock AUv3 plugin, which converted the MIDI clock in AUM to CV and sent it out an ES-9 output as an analog clock. I’ve never really sought to use a MIDI clock as the master clock outside of the iPad. I’ve certainly never used it as the master clock in a Eurorack patch. But this clock was flawless, likely to due CV being generated directly at the source, minimizing switches and pass-thru cabling or USB MIDI jitter. Hopefully CoVariant remains a working plugin in iOS for a while to come as there are currently no other direct MIDI > CV clock converters on the iPad. Veno-Echo was set at x2 on both sides with similar feedback just shy of noon. I also added a smidge of drive in order to enhance the sample reduction I put in the feedback loop. Veno-Echo, with its cross-feedback and width parameter, really can create an enormous stereo field

And so can the Dradd(s). It’s no secret I’m absolutely smitten by dual Dradd(s). Despite this infatuation, my first instinct was to patch in Beads, but Beads just didn’t really have what I was looking for today. At least I couldn’t find it. But the Dradd(s) did. In fact, I had to decide between two modes which both had something very cool to offer. I ultimately chose the Tape mode because the octave up was too much to resist. I slowly started to fade out the oscillators once the Dradd(s) were at full volume, and allowed its magic to guide the rest of the recording, fading out in a glorious wash of the Rain algorithm on the Walrus Audio Slöer.

Modules Used:
Befaco MIDI Thing V2
Synthesis Technology E370
Frap Tools Falistri
Frap Tools Sapel
Rabid Elephant Natural Gate
Nonlinearcircuits Frisson
ST Modular Sum Mix & Pan
ST Modular SVCA
Addac Systems Addac814 6×6 Stereo Matrix Mixer
Venus Instruments Veno-Echo
Pladask Elektrisk Dradd(s)
Knob Farm Ferry

Outboard Gear Used:
Walrus Audio Slöer

Plugins Used:
Alexandernaut Fugue Machine
CoVariant by Alan Clifton

  1. It should be noted that the MIDI Thing also produced velocity CV, I just didn’t use it. ↩︎

Jamuary 2531

I wanted to do something very different today. Throughout Jamuary I’ve done drones, rhythmic pieces that one might even dance to, as well as many other styles. I even have a classic Rings > Beads patch. It had been a long while since I played my 4ms case. I can recall the last patch I used it. It was a pretty cool patch featuring the Ensemble Oscillator (though not one I uploaded to peaks and nulls), and before that was a patch last February. I hadn’t touched it at all during this Jamuary; it was one of the two cases I hadn’t touched at all (the other was my Instruo case), and I wanted to hear those sweet, sweet wavetables again.

I had initially set out to duplicate my 4ms Wonderland patch. I really enjoyed that patch and wanted to see if I could do it again. The answer is probably, at least a close enough version of it, but I ran into the same problem I had when making it the first time. The output levels of the Spectral Multiband Resonator pings are so low as to need significant boosting. In order to get them in an audible range for humans, I needed to boost them by 20dB, then run them to another VCA to boost them yet more. All this boosting added significant noise. I’m sure it’s something I will lean into in the future (who doesn’t like a bit of noise?), but I wasn’t in the mood to deal with it for tonight. So I decided to use the Spherical Wavetable Navigator to trigger itself in LFO > VCA mode rather than drone in the background. I started it with no transposition or Spread, then slowly introduced modulation to both, along with the modulation present in the Browse, Latitude, WT Spread, and Depth parameters of the wavetables, constantly changing the timbre and voicing. This made the SWN go up and down minor scales, and have different arpeggio patterns.

The SWN was sent to the 4ms Dual Looping Delay, another first-use module this Jamuary. What a cool delay that I’ll definitely need to explore. In the process, I used the Industrial Music Electronics Malgorithm Mk2 in the feedback loop, often times a little too eagerly. I manually rode the input level to the Malgorithm. There was a sweet spot where I could get good crunch without starting to runaway with feedback. This crunched up some already fairly crunchy wavetables in a really nice way. The mix was sent to the output mixer for some reverb.

I also decided to have a second crack at the Cutlasses Gloop. Last night was loads of fun, even if the recording wasn’t perfect. What an excellent little instrument. I need to practice looping, especially when trying to use four different loops simultaneously. Looping slower or more sparse material is much easier. It’s definitely a performative skill I haven’t used much of in the past, and my meager skills show. There’s some unintended jumpiness as I tried to shorten and move the individual loops within the large loop. Though far more gracefully than yesterday’s debacle, the transition between the source and the looped recording was a little rough around the edges. I also made a boneheaded mistake with this track: I never put a reverb send on it in AUM (😬), so the only tails it had were the delays tails, which rode the edge of self-oscillation throughout the Gloop section due to giving slightly too much juice to the input level on Malgorithm. It’s better than nothing, but would have been better with reverb and not low-riding oscillation. This was not intentional. I likely mistook it for reverb, though I did know something wasn’t right.

The Shaped Dual EnvVCA and Dual EnvVCA performed all modulation in this patch. All of their outputs were modulating something. The Spread and Transpose on SWN, the Latitude, Longitude, and Depth on the SWN to navigate the wavetable sphere, as well as the Shape of two of the LFOs.

Modules Used:
4ms Spherical Wavetable Navigator
4ms Dual EnvVCA
4ms Shaped Dual EnvVCA
4ms Dual Looping Delay
Industrial Music Electronics Malgorithm Mk2
Cutlasses Gloop
AI Synthesis 018 Stereo Matrix Mixer
Intellijel Amps
ST Modular SVCA
Knob Farm Ferry

Outboard Gear Used:
Walrus Audio Slöer

Improvised and recorded in one take on iPad in AUM via the Expert Sleepers ES-9.

Jamuary 2517

Today’s patch was a long time coming. Several years ago I saw a patch from scratch video by Omri Cohen which used a Befaco Rampage as the base of everything else. It dictated volume, speed, when pitch changes would happen, timbres, and lots of others things besides. I was inspired, and immediately purchased a Rampage. Only I never tried that patch, and moved on to other great things.

Even though I no longer even have that Rampage, I do have several other Function Generators with many of the same features, and after watching the video again recently, I decided today was the day. Only I cheated a little bit. Rather than patch up various Sample and Hold modules to vary envelope length for the higher Brenso voice, I used the Addac506 Stochastic Function Generator which accomplished the same effect. I initially tried using a Falistri but the pitch was always changing a fraction too late for the cycling envelope, and I’d hear that pitch change. I worked on it for a bit, but decided to move on once I realized I wasn’t getting anywhere. To be fair, it was similar with the Addac506, but since I can negatively offset its functions directly, I was able to make it so that always happened in silence, and didn’t give a noticeable blip. I could have accomplished the same thing using a separate offset with the Falistri envelopes, but in a bit of laziness decided I didn’t want to patch it. I did use a certain kind of Sample and Hold for pitch voltage, via Quantermain for quantization into D# Phyrigian (which gives it a dark, mystical feel – like were walking through a dark elvish den), from the Nonlinearcircuits Helvetica Scenario. It differs from a standard Sample and Hold module in one unique way. Rather than using a noise source for sampling voltages, Helvetica Scenario uses a Jerk Chaos circuit running at 300Hz, which, from a practical standpoint, is similar enough.

That varying envelope and pitch control a Frap Tools Brenso, with its wave shape being modulated, along with a slight bit of modulation to the wavefolder. I’ll be the first to admit that I haven’t used Brenso very much. Not nearly as often as I should. I’m generally a bit intimidated by complex oscillators, and have mostly used them as two separate oscillators without the FM or waveshaping features, but in the spirit of loving my Frap Tools case and generally trying new things during Jamuary, I decided to give it a bit of a shot by using the waveshaper and wavefolder features. At least a little bit. I would have used some FM too, but decided to leave that for another day. I did note, however, that while patching Brenso, how beautiful the sound was. Reedy in some ways, at least before running it through the noisy PT2399 delay chip of the Bizarre Jezabel Quarté Mk2. I then ran it through to ST Modular Sum Mix & Pan to slowly pan the signal across the stereo field.

This voice was doubled by the Dradd(s) in Grain mode, time stretching the Brenso part, but at a fairly high clock rate to both shorten the buffer, and produce shorter grains.. I’ve really enjoyed using the Dradd(s) this way of late.

The ever oozing chord base underneath is the Humble Audio Quad Operator with a set chord of the one, three, five, and seven of D# Phrygian (D#, F#, A#, and B). I initially used three cycling envelopes from a pair of Falistris to control the level of those notes, but opted in the end to use a cycle similar to the one I used in Jamuary 2505 and 2511, where the End of Rise gate would trigger the next envelope, allowing the next note to fade in while the current note fades out. I should have used Sample and Hold on these envelopes to vary their length, but opted not to in the end to allow the main Brenso voice to monopolize attention. All four oscillators were mixed to mono in Intellijel Amps, and sent to the Bizarre Jezabel Pkhi Mk3 for low pass filtering before the output. The low passed audio signal was also sent to a the Venus Instruments Veno-Echo, which had its high pass filtering enabled in the feedback loop so as not to muddy the sound. I was never fully happy with how this voice turned out. The mix was too easily blown out, giving it a much darker and grittier feel than I initially intended, though after a bit of struggle, decided to lean into it a bit. I need to find a different way for gentler chord washes like this using saw waves. Some of the individual tones were buried in the mix, and at times the chord is lost.

My forgetfulness finally caught up to this Jamuary day. I forgot to take pictures of this patch before I had to turn everything off for the night so my wife could go to bed, so no pretty eye candy tonight. I may add some tomorrow. If I remember anyways.

Modules Used:
Frap Tools Brenso
Frap Tools Falistri
Addac Systems Addac506 Stochastic Function Generator
Intellijel Amps
Humble Audio Quad Operator
Nonlinearcircuits Helvetica Scenario
Nonlinearcircuits De-Escalate
Nonlinearcircuits Triple Sloths
Bizarre Jezabel Quarté Mk2
Bizarre Jezabel Pkhi Mk3
ST Modular Sum Mix & Pan
Venus Instruments Veno-Echo
Befaco/DivKid Stereo Strip
AI Synthesis 018 Stereo Matrix Mixer
Knob Farm Ferry

Outboard Gear Used:
Walrus Audio Slöer

Plugins Used:
Toneboosters TB Equalizer 4

Performed and recorded in 1 take in AUM on iPad via the Expert Sleepers ES-9.

Pinging Filters in Stereo

Pinging filters in one of my favorite modular patches. You can get lots of different tones, creating very LPG-ish sounds with beautiful ringing decays, booming drums, or melodic clicks and chirps to color your modular masterpiece.

The traditional way to patch a filter for pinging is really simple. Set the resonance on your filter on the verge of self oscillation, run a trigger or gate into the INPUT of your filter, get some pitch CV into the v/Oct input or the filter cutoff CV input. Now patch the output of your filter to your output (or through any effects you might want), and you’re in business. But there’s an inherent problem in many modern filters when patched in this way.

Pinging filters.
Traditional pinging patch.

Oftentimes the input will ping on the rising edge of your trigger, then click on the falling edge, which is not ideal. No one wants clicks in their music, except when you do, so we need a work around.

Some filters, in an effort to mitigate the click problem, have a “Strike” or “Ping” input meant for gates and triggers. The Joranalogue Audio Designs Filter 8 and INSTRUō I-ō47 are 2 examples, as well as the 2 filters I used in this patch.

No “Ping” input? No problem.

For filters without a dedicated input for pinging, simply patch your trigger or gate to an envelope generator with a snappy envelope. A very fast (or even no) attack and a short decay work well. Adjust the decay of your envelope and the resonance on your filter to affect the tail of the ping. It may take a bit of fiddling, and a little can go a long way, but your perfect tail is in there. Hopefully. Patch the filter output to your output module, and on every trigger you’ll hear a new note.

Make Note: Some filters are better pingers than others. Some don’t process v/oct well, or maybe the resonance is too finicky to get the ping you’re lusting after, so if you don’t like what you get with your first choice, move on to another. That said, most filters should work well.

But this post isn’t about just pinging a filter. It’s about doing it in stereo. And while I could tell you that this method is possible with just 1 filter (it totally is), this patch uses 2 independent filters for pinging, and a stereo filter for effect.

We start, as we most often do, with the clock. In this patch, we have the clock feeding 2 separate S&H generators, which will put out unrelated, random CV sequences. Both of these sequences then go through a pitch quantizer before being sent to the v/oct inputs on the filters. The sequences may be different, but we at least want them in the same key (unless you really like dissonance) for aural continuity. The clock also sends a trigger to a random gate skipper, which will allow only a subset of those triggers to pass through, ensuring that the 2 filters never receive the same beat sequence, providing stereo movement and depth. The gate skipper also send triggers to the final stereo filter, and an envelope generator, which is also modulating the filter. Yet another clock signal is sent to the delay to ensure our repeats are in time. The final clock signal is being sent to yet another Random Generator so that it can provide modulation to the final stereo effects filter.

Once triggered, the filters will send their quantized pings to a delay (pings seem to beg for delay), before moving on to the final stereo filter before going to the output. Listen to the result below!

Modules Used:


ALM Busy Circuits Pamela’s New Workout (Clock)
CuteLab Missed Opportunities (Random Gate Skipper)
Frap Tools Sapél (Random)
CalSynth uO_C (Pitch Quantizer)
Joranalogue Filter 8 (Pinging Filter)
Instruō I-ō47 (Pinging Filter)
Make Noise Maths (Envelope Generator)
Make Noise QPAS (FX Filter)
Make Noise Wogglebug (Random)
Venus Instruments Veno-Echo (Delay)

eleaf · Filter Pinging

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