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. ↩︎

A Resonance Wobble Experiment

One of the beautiful things about eurorack is the many happy accidents that we all run into on occasion. Those times when some combination of conditions present at just the right moment seems to produce something magical. You don’t necessarily know what got you there, but nonetheless, here it is and it’s glorious. Though we may not always know exactly what leads to these enigmatic moments of splendor, there are things we can consider when seeking to be able to use those sounds as part of your artistic arsenal. It’s one thing to hap into something beautiful, however you might describe that term, but it’s another thing altogether to reproduce whatever it is you heard to make that magic an intentional part of your sound. To play it, rather than have it fall in your lap.

A couple of days after Jamuary concluded I made a patch on the Make Noise synth that made me stand up and stare. There was a whisper. An oscillator speaking softly into a filter’s ear, quivering as it tried to muster enough courage to get sound out. It wasn’t unlike bowing a string as lightly as possible, or trying to play a wind instrument as quietly as one can. There was a vulnerability in the voice, seemingly lacking the confidence to speak, or like trying to speak when you’re crying and your lips quiver. There was a wobble that was absolutely intoxicating, and I was set on trying to reproduce that wobble.

When I first set out to try and recreate this sound, I first isolated the conditions of the patch I wanted to emulate. Of course oscillators can’t speak softly. They only know one output level, generally speaking. I documented every patch connection and knob setting from this sub-patch. I verified modulation sources and any peculiarities. I thought about this patch a lot, writing extensively in my Notability patch book, and narrowed it down to three factors. At least theoretically.

  1. As low a level going into the filter as possible. On my original patch, I used QPAS as my first filter, and controlled levels with the input VCA knob. I initially did this out of necessity because the other voice in the patch was very quiet by its nature, and when any real level was given to the oscillator going through QPAS it was too loud. I discovered later that night that the lower the level, the better the conditions for interesting wobbles. If your filter does not have input level control, you can use an attenuator or VCA before going to the filter input.
  2. A filter with some fairly aggressive resonance. It need not scream like a Polivoks, but the resonance needs to be pronounced before it goes into self oscillation. If the resonance is non-linear, it’s even better. I’ve also surmised, perhaps errantly, that a vactrol-based filter would be better suited to this job because of the inherent drag and voltage drift of vactrols. The filter creating pronounced wobble in my Make Noise patch was QMMG, a vactrol-based filter, processing a signal that had already gone through QPAS. I could be wrong, but my experiments trying to reproduce the wobble seem to bear out this conclusion. I don’t have a vactrol-based filter in my main synth, but none of the filters I used in my experiments had the same sort of wobble as that produced by the QMMG.
  3. A slow moving modulation signal that moves the cutoff frequency through the fundamental frequency of the note. I’ve found the slower the better, but there are diminishing returns to that proposition. When you add resonance to a filter, you’re creating a small hump in the EQ curve at the cutoff frequency by feeding it back into the filter’s input. When that cutoff frequency intersects and passes through the fundamental frequency of whatever signal you’re passing through it, you get a small wobble. The resonance itself and the modulator’s frequency and shape can alter that wobble some, and can change its character, as do any curves you might put on your modulating signal.

Of course all of this was theoretical, and much of it still is, even if I’ve received some form of verification via Google AI, and tangible signs that I’m on the right track through my subsequent experimentation.1

When I set out to make a patch yesterday, my goal was to first experiment with recreating filter wobble through my main synth where I have a plethora of filters of all sorts. My first thought was to experiment wholly within the Frap Tools Cunsa. I can create sine waves with the first filter and still have three filters with which to experiment, all with normalized patching to make things simple. I was pretty quickly able to create some wobble using my three guideposts listed above, but it was very consistent, and exciting as it was to know I was on the right path, I felt that perhaps the Cunsa was simply too polite a filter to get the best results. Abandoning Cunsa, I next went to the Joranalogue Generate 3 feeding Filter 8, but I never felt like I could get anything close to what I wanted. The cutoff was always too high, and I couldn’t tame the harmonics in a way I wanted. So I switched to a single sine wave from Filter 8 feeding the Bizarre Jezabel Seju Stereo, which was okay, but not special, so I went to the Pkhia, which didn’t work very well. I moved on to the Pkhi Mk3, and had a promising start, but it didn’t progress much. Finally I went to the Blossom, a multi-output filter inspired by the legendary Mannequins Three Sisters, and I heard…something interesting. The wobble was there, and had a bit more character than the simple hump like the rest of the filters. I had found the subject for the rest of the day’s experiments. I spent well over two hours exploring different filters, and of those I tried, a simple sine wave into Blossom was definitely the most compelling. I have other filters that I think are good candidates, namely the Verbos Amp & Tone and Instruo I-ō47, but neither of those cases were in the synth when I turned it on. I’m definitely interested in trying those filters, as both have just the right kind of resonance, I think, to be compelling options.

After I’d finalized a base sound I wanted to use for the rest of the patch, a single sine wave into a resonant low pass filter, I worked up a sequence in C Lydian on the very excellent Doboz T12, and went to work. Like the voice used in my Make Noise patch, this voice would also be completely un-gated, sauntering along, only being level modulated in the filter by the slowly moving function of a cycling Contour 1. The cutoff point is set lower than the lowest fundamental frequency so that there would be times when no notes of the sequence come through. Because Blossom doesn’t have level input control, I ran the output of Filter 8 through an attenuator to initially make the sound as quiet as possible while still being (mostly) audible.

I decided to use a staggered clock. One that is gated by a clock divider, so as to never have continuous repetition. I multed a single x1 clock output from the Sitka Gravity to the Nonlinearcircuits Divide & Conquer in order to create my gate. Because the Gravity is in its infancy, there are several basic things it can’t do. As of now, Gravity’s clock (and sequencer) only outputs triggers, and not gates, so I couldn’t use the duty cycle of a gate output (like those on Pamela’s Pro (and New, and OG) Workout) to gate the x1 trigger that would ultimately go to the clock input on the sequencer. I wanted the clock to start and stop every five beats, and Divide & Conquer was able to provide a gate that enabled that staggered clock for my sequence to follow. The sequence itself is simple. It’s a couple of scale lines going up, with a very low probability (11%) of getting a quantized random pitch within seven semitones (a fifth) of any given step of the sequence. But because the cutoff frequency of the filter goes below the lowest fundamental pitch, the sequence flows in and out and isn’t steady. Notes hold in beautiful ways, and the sequence doesn’t repeat despite being only 16 steps long.

Once through the now occasionally wobbling filter, the audio went straight to the Bizarre Jezabel Mimosa. Mimosa is what I consider to be the most beautiful distortion I’ve heard in any format, short of very high dollar guitar amps. Of course the word beautiful is doing a lot of heavy lifting here, but what I mean is that it can heavily distort something, while still allowing the source to shine. It adds life, even when the dials are pinned. No matter what, you can always let some of the original dry signal through which helps keep shape in the audio regardless of the amount of distortion is applied. From gentle piano notes and sine waves (such as those in today’s patch) to ripping saw clouds Mimosa just does the right things whether using it for some gentle saturation or full on sonic destruction.

In this patch Mimosa started gently, with both the output volume and distortion amount both turned low. As the piece progressed, gain was adjusted upwards at multiple points. The first place was the original audio signal on the way into the Blossom. This allowed its resonance to growl a bit more rather than wobble. Higher input levels into the filter also mean higher output levels from the filter, and Mimosa is very sensitive to input level. Even at the same knob settings, input level is a crucial determinant of the final sound. Lower levels at the input might just have a bit of coloration or slight crunch, whereas loud sounds will rip or soar. It’s part of Mimosa’s magic. After I adjusted the initial input as loud as I dared, I started to slowly raise the output volume and distortion amount on Mimosa, as well as the amount of wet signal. From gently whispering and quivering to finally finding one’s voice to sing, all from nothing but subtle gain changes along the way. From Mimosa, the audio went to a new addition in the synth; the Addac Systems Addac814 6×6 Stereo Matrix Mixer to be distrusted to several effects.

It should be reiterated here that every sound is this patch arises from one single sine wave fed by one simple sequence, with but a single parameter being modulated by a lone triangle function (the filter cutoff). Of course that isn’t the only sound in total. That lone sine wave is repeated all over the place with overlapping delays, looped with four simultaneous digital tape heads and a delay of its own, and reverberated. The first delay, a Bizarre Jezabel Quarté Mk2, mostly added some lovely texture. A bit of a wash of decays in the wake of the melody, its gritty tail disintegrating into nothingness, which added depth and color. Repeats were set to moderately long, with a slow(er) delay time. With the PT2399 delay chips, the longer the delay time, the noisier it will be. The second delay was an Olivia Artz Modular Time Machine, with 4 active taps. It’s clear digital voice echoing the distorted sines near perfectly. Both delays are set to different times which really served to fill out space and maximize this one simple voice with the most basic of sound waves.

As beautiful as this very simple sequence was, I wanted to see if I couldn’t perform some complimentary embellishments, and decided to once again delve into the Cutlasses Instruments Gloop. I’ve only used Gloop a couple of times, but it’s already captured my attention. Some modules take some time to gel with. Despite some sloppy transitioning in my first couple of uses, I immediately took to Gloop. Its interface is (mostly) intuitive, and it’s a capable looper with some very cool tricks. It’s pretty easy to create compelling loops with Gloop. That said, it does have some drawbacks, at least in its current iteration. Though it’s packed with some clever effects that can be eminently useful with a looper, delay, reverb, and a host of tape-related effects like tape degradation, wobble, noise, and saturation, these effects can only be used on one channel or the other, and not both. Though Gloop has two outputs, it’s not really stereo, but dual mono. Each of the four heads can be panned in a stereo fashion and be used in one or both outputs as if it were a stereo signal, but for reasons I don’t understand the effects can only be used in one output at a time. This imbalance can definitely be a problem when trying to create a consistent stereo field. I was hoping to use the degradation effect, wherein the audio degrades as it would on a tape machine with each successive loop, fading out to nothing after a time. In loopers this is generally simulated by constantly low passing the signal at progressively lower cutoff frequencies in order to gradually roll off the highs. It’s a crucial component of Frippertronics, for instance. Allowing a loop to fade to nothing is also a beautiful way to end a track, and unfortunately I can’t do that with Gloop while using both output channels. In lieu of using Gloop to add tape hiss, I was able to add noise to both channels in the mixer via the very excellent DAW Cassette by Klevgrand, but that was an improvised half-measure. I think I can patch a workaround, but it definitely won’t function in quite the same way. A slow moving negative function into a wide open filter cutoff should get me at least part of the way there. Timing would be an issue. How long should this envelope be? What happens if I get to the end of the function, and I haven’t pressed stop on the recorder? Will the cutoff reset to fully open? That would be bad. But those are problems for another day.

I recorded a length of the sequence to Gloop, then while the sequence continued to play configured the four play heads and slowly started to raise the level on the looper, while lowering the level of the continuously sauntering sequence. Though this transition isn’t perfect, it’s much smoother than in tries past. I would use a crossfader like the WMD AXYS to more smoothly move between the two parts, but because the individual voices were being multitracked separately, I crossfaded in the mixer by hand using the Michigan Synth Works XVI Faderbank CV and Midi controller. The first and fourth heads were hard panned left and right at 2x forward and 4x in reverse respectively, while heads two and three were panned in the middle at 1x forward and .5x forward. I manually played the loop size and location within the loop of all four heads until it I manually faded out the hard panned parts before fading out the base melody and its half speed sibling. But not even Gloop was without its own dedicated delay, the ever-excellent Venus Instruments Veno-Echo. I used a x4 output from Gravity, with a /3 clock division set in Veno-Echo, which gave me a dotted eighth note delay, an always interesting pattern.

Both voices were mixed together in AUM and sent to the Walrus Audio Slöer using the Rain algorithm with almost no diffusion, and the clock speed at its slowest, adding to an already textured outcome. A medium long decay and high modulation finish off the track.

Modules Used:
Sitka Gravity
Nonlinearcircuits Divide & Conquer
Doboz T12
Joranalogue Filter 8
Joranalogue Contour 1
Bizarre Jezabel Blossom
Bizarre Jezabel Mimosa
Bizarre Jezabel Quarté Mk2
Addac Systems Addac814 6×6 Stereo Matrix Mixer
Olivia Artz Modular Time Machine
Cutlasses Instruments Gloop
Venus Instruments Veno-Echo
Intellijel Amps
ST Modular SVCA
Knob Farm Ferry

Outboard Gear Used:
Walrus Audio Slöer

Software Used:
Klevgrand DAW Cassette
Toneboosters TB Equalizer 4

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

  1. I put very little stock in the accuracy of AI at this stage in its development. However, it stated the same three conditions I had independently surmised, and so choose to engage in a bit of sweet, sweet confirmation bias. ↩︎

Jamuary 2510

Between work and the second snow storm this week I was super short on time, which made today another iPad only affair. I started with something similar as with Jamuary 2507 and 2508, the Alexandernaut Fugue Machine feeding two instantiations of Decent Sampler, one with cello samples and the other with viola. Both go through some delay and reverb, and later Fluss, a beautiful granular synthesizer by Bram Bos and Hainbach.

I have lots to work to do with these sort of patches, and with this one in particular. I’m a midi novice, and still inexperienced with software instruments, particularly those on the iPad, so good chunks of my time were figuring the best way to do X or Y. It’s a pain, but the effort has not gone unrewarded, and, more importantly, I’ve opened a new world of possibilities for the future.

Plugins Used:
Alexandernaut Fugue Machine
Decidedly Decent Sampler
Numerical RP1 – Dual Digital Delay
Blue Mangoo Stratosphere Cloud Reverb
Bram Bos + Hainbach Fluss

Performed and recorded in 1 take in AUM on iPad.

Jamuary 2508

I was short on time yesterday, so put together a reasonably simple patch on the iPad. This Jamuary I’m purposefully trying to use unfamiliar techniques with unfamiliar instruments, and that’s what yesterday was all about in the little time I had. But the patch turned out so beautifully that I wanted to take some time to explore its possibilities in the modular. My first thought was to try and use the Oxi One as a Midi > CV converter so that I might patch the outputs of the Alexandernaut Fugue Machine to something like the Synthesis Technology E370 or some other quad sound source. But despite spending the better part of three hours trying to figure it out,1 I still had achieved no progress and so abandoned the idea and decided to do the next best thing. To patch a more intentional version of Jamuary 2507 into the modular and run it through several effects and see if I couldn’t come up with something new.

The initial patch is the same. Fugue Machine feeds the Klevgrand Speldosa and Decidedly Decent Sampler software instruments in AUM. Yesterday those went to reverb and I called it a day. The patch was beautiful and full of promise. Today went much further. The outputs of both Speldosa and the Cello samples were sent from AUM, via the ES-9 outputs, to the AI Synthesis 018 Stereo Matrix Mixer so that they might be spread around the system to three different effects, shifted and morphed matrix style, and finally sent back to AUM before getting some reverb. Though I’m trying new techniques with new things, that doesn’t mean everything in a single patch, lest I become overwhelmed and frustrated.2 The effects I chose were the Venus Instruments Veno-Echo,3 Pladask Elektrisk Dradd brothers, and the Rossum Electro-Music Panharmonium. Speldosa and the cello samples were sent to the delay, with Speldosa only going to Panharmonium, while the cello only was initially sent to the Dradd(s), before adding the delay to the Dradd(s)’ input, slowly adding more, and allowing those higher pitched notes to be granular-ized and spread through the stereo field. The Dradd(s) really turned out to be the highlight, though the delay isn’t far behind. Panharmonium sounds nice, as it always does, but seemed to get lost when it wasn’t leveled as a prominent voice in the mix at a given moment.

Modules Used:
AI Synthesis 018 Stereo Matrix Mixer
Venus Instruments Veno-Echo
Pladask Elektrisk Dradd(s)
Rossum Electro-Music Panharmonium
Nonlinearcircuits Triple Sloth
CuteLab Missed Opportunities
Calsynth Twiigs
Frap Tools 333
Knob Farm Ferry

Outboard Gear Used:
Walrus Audio Slöer

Plugins Used:
Alexandernaut Fugue Machine
Klevgrand Speldosa
Decidedly Decent Sampler
Toneboosters TB Equalizer
CoVariant

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

  1. To be fair, I struggle with just about everything with the Oxi One. I really need to revisit it with purpose. ↩︎
  2. I recently suffered that sort of frustration when I put two completely unfamiliar modules in my Xmas 2024 Synth. It was an exercise in frustration when it should have been a relaxing time. ↩︎
  3. I used CoVariant, a now seemingly discontinued midi > cv plugin for the iPad to send out an analog clock from the iPad that is perfectly in sync with the midi clock generated by AUM. I will never delete this plugin as long as it continues to work. It also does midi > CV conversion (but I couldn’t figure it out). ↩︎

Red Orange Yellow Green: A Synth Test Turned Beautiful

While I was testing a synth I built for my brother and me to play while on a family vacation, I wanted to see if I could get something more ambient from what I perceived as a more rhythmic-oriented case. I have a master clock, a sequencer, a chaotic/random gate producer that likes the time grid, all dedicated to staying in time. My brother is more of a shake your booty type of guy and I wanted to bring something he would enjoy too, so rather than chaos and random ahoy, I put in several modules that he could feel comfortable with too. But rather than resign myself to grid based tempos and rhythms from this synth, I ventured to see how I might go about creating something more freeform. Instruments tends to direct their players towards certain ways of doing things. Modules do the same via their UI cues. All modules demand some particular workflow which lends towards different styles as a result of their design. But this subtle push by module makers doesn’t preclude using their designs in ways that maybe they weren’t designed to be used, or in ways they hadn’t considered. Individual case builds likewise push musicians to patch in certain ways.

Since this was a test, I started with a familiar idea and tried to see how I might create an irregular clock in order to use Stochaos to hit the Disting Ex in the SD Multisample mode using the LABS Soft Piano samples. It’s one of my favorite voice patches, and generally it sounds beautiful. Enter the Sitka Instruments Gravity.

The Gravity is a 6hp, 6 output master clock. It doesn’t have the sorts of clocked modulation options that something like the ALM Busy Circuits Pamela’s Pro Workout has, nor does it have the quick, hands on manipulation of the Make Noise Tempi. But it does have a fair few things going for it. It’s a rock solid clock, and easy to manipulate, even at first glance. The UI is intuitive, and its distractions few. Each output has three modes: Clock, Probability Clock, and Sequencer. The clock and probability clock does what it says. The outputs put out short triggers according to a clocked division or multiplication of the master tempo.1 Timekeeping is not exciting, however it is crucial. But the killer app in the Gravity is that its tempo can be modulated by control voltage, a feature not found in every master clock. At this realization I knew just exactly how I was going to get my wonky clock.

After plugging in a smooth random LFO from Batumi II + Poti II and tuning its frequency and amplitude to taste, we had a modulating clock that randomly floats above and below the master tempo. The Gravity gives a numerical option when the master tempo is being modulated, called Range. It’s simply a number that goes up by tens. Although initially I wasn’t sure just exactly what that number represents, the developer noted that it’s a fixed maximum BPM deviation above and below the set master tempo. So if your tempo is set to 80bpm, for example, with a Range of 10, it will swing as low as 70bpm with -5v of CV, and as high as 90bpm with +5v of CV. Clever. Subtle undulations is one thing. Wild tempo fluctuations is something else altogether, and having a defined maximum range built in to the modulation is a really good way of making it easier. This clock was fantastic, subtly shifting faster and slower. Being anticipated, while not being predictable, and never on a strict grid. Perfect.

Although I didn’t need more triggers than what Gravity can supply to ping the Disting Ex, I did want those triggers to extend laterally, never close to anything we could call a pattern. Stochaos once again provides a beautifully timed spread of triggers which form the basis of the piano voice in the patch. It always takes some clock adjustments to get the triggers just so. In this patch I ultimately used a x8 multiplication of that modulated clock with a 20% chance of skipping a beat to drive Stochaos. This kept triggers coming at a reasonable pace for Stochaos to spread the gates through its various outputs, helped by the retrigger setting in the SD Multisample algorithm to “Synth” to keep it from going too cluttered with notes.

For pitch, I used three of the four Swell Physics outputs into Quantermain (in C major). One of the quantizers was set to quantize to all 7 notes in the scale, with the other two set to quantize only to the root, third, and fifth. This turned out to be a wonderful method of getting pitch. The outputs on Swell Physics are all inter-related, and something akin to phased LFOs, only the phasing is more organic. Swell Physics is not a single speed with waves sliding back and forth, but the movement of the ocean, with ebbs and flows that can’t be strictly controlled, and where each wave affects the others. All of their speeds fluctuate, as do their amplitudes. This set of waves allowed for a good spread of notes, with minimal dissonance.

The Soft Piano sample outputs from Disting go to the Qu-Bit Nautilus for some unclocked delay. Feedback and Depth are lightly modulated by the highly attenuated AVG output from Swell Physics, while a highly attenuated saw ramp LFO from Batumi II + Poti II modulates Reversal. The patch starts with no Chroma (Qu-Bit speak for an effect inserted into the delay feedback path), but heavy distortion is introduced later on as the patch heightens. Using the delay feedback line for distortion, as opposed to using distortion before the delay, still allows for the piano notes to sing through quite clear, before being clipped to hell over and again as the repeats fade away.

After going through Nautilus, the signal made its way to the Make Noise QPAS for some light HP filtering. In most situations I would run a hard clipped signal through a LP filter to shave off some of the most egregious harmonics, but for some reason I preferred the HP filtering in this patch (I tried all four stereo outputs before deciding on HP filter), and so I won’t be too harsh on myself for an intentional decision made in the moment. The only modulation is via the 1 < 2 and 3 > 4 gate outputs on the Swell Physics via the CuteLab Missed Opportunities to both !!¡¡ inputs for some occasional shooting stars.

But getting a pretty flow of random piano notes wasn’t the final goal. The final goal was to test the new elements of this case so I’d have a basic understanding of how to use the case in a style I enjoy, and hopefully avoid having to constantly dig through manuals during the little time I’d have to patch on the trip, which brings me to a real beast of a module: the new Doboz T12, a 17hp (😕) touch controller, arpeggiator, and sequencer. I had half-assedly tried to get it going a couple of times over the last couple of weeks, but came up empty both times, so it was time to sit down with the manual and dig in.

At first I was intimidated by the T12. There’s not much on the panel outside of 12 touch plates, a screen, a couple of buttons, and an encoder to give you cues, and the options in the screen are many. But once I got over the initial hurdle of Step 1, the intuitive nature of the screen UI took over, which makes it generally simple to navigate and use. The T12 has 4 modes: a touch controller, an arpeggiator, a very straightforward up-to-32 step sequencer, and a more complex extended functionality step sequencer. Although I certainly want to understand the Complex Sequencer, my aim was to tackle the touch controller (why I initially bought the T12 to begin with), the arpeggiator, and the simple step sequencer.

Despite being a bit overwhelming at first glance, having loads of options in the UI, the T12 workflow is both fast and intuitive. Not only are there the standard pitch CV and gate outputs, but also a secondary CV output for something other than pitch. You can set vibrato, including a delay, gate probability, random note probability, touch behaviors, and many other facets of your sequence quickly and easily. The AUX CV output can send envelopes, slewed gates, secondary raw CV, amongst other stuff. The T12 is a really powerful, highly flexible, and intuitive module that is fun to use. Just don’t forget to save your work in one of the many save slots, or else you’re gonna lose all your shit. Ask me how I know. Fortunately this particular patch is pretty easy to reproduce should I have the need.

For this initial patch I wanted to keep sequencing as simple as possible. A slowly plodding 10 note, repeating sub-bass line via the Humble Audio Quad Operator that would flood the audio and shake the room. I was loosely aiming for a post-rockish feel in the progression. It’s intentionally loud, though not so loud that the piano can’t still be clearly heard. With the wandering clock set to /8, and after a smidge of tuning the individual notes in the sequence to what I wanted, I pretty quickly got what I was after.

Which isn’t to say that the bass line is without issues.

Firstly, I’d like to note that both the high level and super-low frequencies were exactly what I was trying to accomplish. I was looking for film score kind of epic. The kind of bass that rattles walls and that you can feel in your stomach. That said, there’s far too much audio gear, including very high quality audio gear, that has a difficult time reproducing C1 (32.70Hz). My audio monitors, a set of Focus Alpha 80 studio monitors only reach down to 38Hz before the cutoff becomes pronounced. At 32Hz, the tone could still be heard, but not with near the authority it should have. D1 (36.71Hz) had similar issues, although not nearly as marked. By the time we get to E1 (41.2Hz) things are booming, but of the 10 notes in the bass sequence, only 5 can be heard with the vigor I intended, and that’s through a good pair of studio monitors. Fortunately the cans I used to record this patch, a set of GK Ultraphones, and the AirPods Max Bluetooth headphones I use for general listening, have no pronounced problems with reproducing the low C. But if I were to record this patch again, and I’m highly considering it, I’ll pitch the entire piece up 4 full semitones (E1) to avoid that conundrum. It’s one thing for a bass heavy piece to not play through phone, tablet, or laptop speakers. It’s a different sort of problem when high quality studio gear can’t do it. Any system with a subwoofer should really shake the foundation, but you shouldn’t need a subwoofer to properly hear music.

The last voice was a spur of the moment addition to the patch. I didn’t know exactly what, but I knew the patch was missing something. It needed one last final touch. It needed Plaits. Though it certainly has its limitations, Plaits is one of the most versatile and best sounding oscillator modelers available. Everything from kick drums, a scaled down Rings algorithm, and FM, plus more is possible with Plaits. At first I didn’t really know what I wanted, other than it be sparse. The Rings algorithm didn’t really fulfill the role. It took away from the patch as much as it added to it.

But as I made my way through the modes one by one, I landed on the final green algorithm: Vowel and speech synthesis. This would normally be unremarkable, but as it happened, I kept hearing the word “Red.” How the various knobs had been set while testing other algorithms landed me smack at the beginning of the colors of the rainbow. I slowly turned the Morph knob to see what else was hidden there, and found a slew of words. At first I set up modulation of the Morph to cycle through the words quickly. Think Robot Auctioneer. And although this addition certainly moved me in the right direction, it still wasn’t the destination. There were too many words being synthesized too quickly. It was slightly distracting, and not wholly complementary.

After a bit of envelope experimentation, I settled on 4 words: Red, Orange, Yellow, Green, “said” at a slightly slower than “natural” pace, and with a fairly thin tone. This gives the voice an almost sad feel, which I think slightly tempers the optimism and hope found in C major piano alongside an epic bass line. It brings a bit of the non-perfection and often lonely feel of reality back into scope, and that even non-perfection and loneliness can be contained within beauty.

After repeated listens, I know that I wouldn’t send any pitch information to Plaits were I to record this again. I think having it repeat at the same pitch would have an even larger impact, and be more focused.

One last new module I used is the Intellijel Amps VCA. Two of them chained, actually. Although I initially planned and built this case with an Intellijel Quad VCA, I recently realized the power of fully cascading VCAs,2 and decided to replace one of my Quad VCAs with this pair of Amps. Even with the first use I could see the utility in cascading inputs. The ability to patch one input and get out several signals that are related, yet separately attenuated and/or modulated, for use throughout a patch is powerful. Of course multiple related outputs could also be accomplished by patching multiplied copies of the signal into all four VCA inputs, but with cascading inputs we can eliminate at least six patch points and three patch cables. Efficiency is key. Add in ring modulation and signal inversion, and Amps is a powerful tool indeed.

Modules Used:
Sitka Instruments Gravity
Doboz T12
Nonlinearcircuits Stochaos
Expert Sleepers Disting Ex
Humble Audio Quad Operator
Mutable Instruments Plaits
Mutable Instruments Veils
CalSynth Changes (MI Stages) (w/ quimem)
CalSynth uO_C (w/ Phazerville)
Addac Systems Addac508 Swell Physics
Xaoc Devices Batumi II + Poti II
Make Noise QPAS
Intellijel Amps
Qu-Bit Electronix Nautilus
Blue Mangoo Stratosphere Cloud Reverb (AUv3 plugin)

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

*****

  1. According to the developer, Gravity should (fairly) soon get a firmware update which adds the ability to adjust gate duty size as a prominent feature, rather than only short 15ms triggers. This addition would make the Gravity outputs far more useful as a clocked modulator, and make it able to trigger longer ASD or ADSR envelopes that are determined by gate length. The developer has also noted that MOAR divisions and multiplications of the master tempo will be added.
  2. A fully cascading VCA is one in which all inputs, CV inputs, and outputs are normalized to the following channel until the normalization is broken by a plugged in jack. This configuration allows for a flexible array of both CV and audio patching, capable of complex mixes or routing.

Swell Physics – A Fourth Revision

Although I sometimes re-work a patch after recording it, I generally make a couple of obvious (to me) changes, re-record it, and move on to something new. But something about my Study of Addac’s new Swell Physics captivated me, and compelled me to go through several revisions and re-records to flesh out something interesting.

The base of the patch is the same: Swell Physics sends out modulation, which controls the level of the four voices of the RYK Modular Algo, and drives most of the modulation in the patch. The RYK Modular Algo output runs through a filter, and into Beads. All of these are mixed and sent to a reverb. But just about every aspect between those modules has changed. Modulation has been added, subtracted, and tweaked. I went through 4 filters before finally finding one with the right sound. I’ve experimented with different settings on all of the modules to find just the right sound. I added in delay to give some subtle length and a nice tail to the swells as well as the spray (which was also added). With dramatic results, I also changed reverb to the beautifully haunting Walrus Audio Slöer. All in all I spent upwards of 12 hours building and tweaking this patch, making no fewer than 13 different recordings, constantly evaluating the results and searching for way to improve it.

It’s hard to document all of the changes. There were so many. But suffice to say that nothing within the patch went without heavy scrutiny and experimentation. It’s the first thing that I’ve made which resembles something like a finished piece of music.

Modules Used:
Addac Systems Addac508 Swell Physics
RYK Modular Algo
Intellijel Quad VCA
Bizarre Jezabel Pkhia
Joranalogue Orbit 3
Joranalogue Filter 8
Joranalogue Compare 2
Frap Tools Sapel
CuteLab Missed Opportunities
Auza Wave Packets
AI Synthesis 018 Stereo Matrix Mixer
Mutable Instruments Beads
Mutable Instruments Veils
Atomosynth Transmon
Knob Farm Ferry
Olivia Artz Modular Time Machine
Walrus Audio Slöer

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

A Patch In Which The OAM Time Machine Does The Heavy Lifting

I keep it no secret that I’m a certified delay junky. I love all kinds of delay from murky analog repeats, to the beautiful compression of tape delay, to pristine copies of digital delays. I dig them all. Even if my collection has shrunken significantly, at one time I had over 30 delay pedals, I still have a few delay pedals I consider choice, like the Oto Bim, Vongon Polyphrase, and the Free The Tone Future Factory FF-1Y Future Factory. I have dual Echofix EF-X2 tape delays. And it shouldn’t be a surprise that I have several Eurorack delay modules. From the mighty Verbos Multi-Delay Processor, to the Xaoc Devices Sarajewo, and the Qu-Bit Electronix Nautilus to the Venus Instruments Veno-Echo (plus yet more), I’m covered when it comes to Eurorack delays. But when the new Time Machine from Olivia Artz Modular was announced, I knew there was no way I could pass on it for too long before I hit “Add to Cart.” Due to a confluence of random events, I was informed by OAM within minutes of the Time Machine being released for sale at Perfect Circuit, and so was able to snag one quick without the ~6 week wait time if you order direct from OAM. I would have ordered one anyways, but bypassing the wait was a nice surprise, and moving their product through retail stores helps them get more retail orders and wider distribution.

When I imagined the Time Machine, I was imagining a stereo version of the Verbos Multi-Delay Processor. I’m sure much of the Time Machine was influenced by the MDP, from its looks to its multi-tap nature. And although it can certainly replicate some of the things the MDP does, the Time Machine is definitely something different, and highly rewarding. True stereo is a wonder to behold.

One thing I’ve learned about testing delays is that if you really want to hear its voice, you need to feed it short transient signals. This moves the dry signal more out of the way and allows the delay room to breathe and be heard on its own terms. I use these quick notes to test every delay I get. With Eurorack, that test is almost always short pings in an LPG in order to see what’s its limits are. How clean (or dirty) are the repeats? How does the feedback behave? Does it do The Thing?1 How do the taps behave? How does the feedback go into entropy? This simple test allows me to really evaluate how a delay sounds and behaves.

This er of this patch is sets of sparse plucks of the Bard Synthesizers VTG (Vacuum Tube Gate – it sounds wonderful, if not quite like a traditional LPG). These plucks are created using the Humble Audio Quad Operator, which has the 2 waves being modulated by The Hypster, and one of the Ratios modulated by the Bindubba, into the LPG’s two input channels. The gates are hit by envelopes created by the CalSynth Changes (MI Stages), which is triggered by chaos-derived gates of the Stochaos. From the VTG, it goes straight to the matrix mixer, and onto the Time Machine.

After tweaking the Time Machine faders to get a delay pattern I really liked, I was pleased with what was happening, but I wanted more. Delays are cool and all, but dancing repeats do not make a track. After a second it clicked: “Panharmonium really likes short transients!” Although I wasn’t at all sure what I might get out of the Panharmonium, I thought it would be interesting, and that assumption was correct. After wiggling some knobs and adjusting the sampling interval (using a division of the clock used for the Time Machine), what I got was far more than interesting. It was the best thing I’ve heard from the Panharmonium in my own practice. A sort of distorted cello/upright bass sound that really fills in the space, and is harmonically relevant to the repeats that form the base of the track. Even if you can’t hear the repeats themselves through the Panharmonium, the sound of the it is a direct transliteration of those repeats in the form of resynthesis. Without the repeats, the Panharmonium isn’t making any sound. Since the Panharmonium sounded almost like something you’d hear in a sludge metal or Post-Rock context, I decided to also route the Panharmonium output to the Bizarre Jezabel Mimosa and really give it some drive, which was a perfect choice.

The patch is finished off with some reverb courtesy of the Oto Bam Ambient algorithm.

Modules Used:
Humble Audio Quad Operator
Bard Synthesizers VTG
Nonlinear Circuits Stochaos
Nonlinearcircuits The Hypster
CalSynth uO_C
CalSynth Changes (MI Stages)
Olivia Artz Modular Time Machine
Xaoc Devices Batumi II
Xaoc Devices Samara II
Rossum Electro-Music Panharmonium
Bizarre Jezabel Mimosa
AI Synthesis 018 Stereo Matrix Mixer
Knob Farm Ferry
Oto Bam

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

__________

  1. When it can sit on the edge of feedback without running away uncontrollably. It’s even better when it can do that at a low volume, while still allowing your repeats to go through at full volume. The EF-X2 is masterful at this trick.

A Chordal Soundscape With The Pianist, Odessa, Panharmonium, And A Couple Of Tape Delays

I’m not going to go in depth on this patch as there’s a lot of modulation happening and I can’t possibly document it without rambling in circles. I’m also using several techniques I’ve already written about, like using chaos at a clock, running a delay into the Panharmonium, using tape delays, and panning using VCAs.

A couple things of note:

The Echofix EF-X2 tape delays have incredibly good overdrive. The clipping is all analog and is both warm and musical. I would absolutely use the preamp alone to add anything from subtle saturation to thick overdrive. All of the distortion in this track is from the pair of EF-X2 tape echoes.

The Pianist by NOH-Modular is a highly capable chord sequencer. Building progressions is easy and the interface is intuitive. It certainly has faults (that I’ll discuss later in a more comprehensive review), but overall it does an absolutely fantastic job.

Odessa is Odessa and I will make no apologies for it.

This is the first patch during which I’ve used both the go-to AI Synthesis 018 Stereo Matrix Mixer alongside my new mono (voltage controlled) matrix mixer, the Transmon by Atomosynth. I used the latter to mix the Sofia Mix output with the Odessa partials outputs, while panning the Odessa fundamental slowly from left to right (although I can’t really hear the panning in the mix if I’m honest). Having a voltage controlled matrix mixer with individual outs for 12 of the 16 channels, along with 8 channels that can attenuvert makes for a compelling piece of kit. The possibilities are endless.

Modules Used:
NOH-Modular Pianist
Xaoc Devices Odessa (+ Hel)
Xaoc Devices Zadar
Xaoc Devices Lipsk
Xaoc Devices Erfurt
Xaoc Devices Samara II
Xaoc Devices Batumi II (+ Poti II)
Rossum Electro-Music Panharmonium
Holocene Electronics Non-Linear Memory Machine
Atomosynth Transmon
AI Synthesis 018 Stereo Matrix Mixer
Nonlinearcircuits The Hypster
Nonlinearcircuits Divide & Conquer
Nonlinearcircuits Triple Sloth
Auza Wave Packets

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


FX Sends (and Returns Too)

As I was restructuring my synth into Subsystems, I was adamant that I wanted a varied and flexible outboard FX section. Although I love Eurorack FX, I’m fairly convinced that many FX are better outside of the case, rather than a module in it. Modulation sounds great on some FX, like delay, but causes chaos in others, like reverb. I’m know that there are lots of great pedals that aren’t in euro form, and that pedal companies have been perfecting FX for decades. The first stereo reverb, for instance, came about long before Eurorack was even invented. Why reinvent the wheel, or limit myself to only euro FX? That’s counterproductive and boring.

But I also had a logistics problem. FX sends and returns are traditionally handled through a patchbay, and as mightily as I tried, I couldn’t imagine a good way to implement a patch bay in my Eurorack system. Patchbays make connecting audio gear simple and intuitive. I use them all the time on my recording/editing desk. But this time it was not meant to be. The Eurorack specific patchbays on the market aren’t quite flexible enough. The Patchulator and Patchulator Pro don’t offer full-time access to every effect from any given number of sources. Theoretically I wanted to be able to play all 10 of my effects simultaneously, with 10 different sources. A patch bay makes this easy, but without one I’d have to come up with something different.

That something different took a while to assemble, and for all I know may not even be the best way. But even if it isn’t the most efficient way, it’s a way that works. I can run any source to any effect at any time. I can chain effects with ease. I don’t have to do any unplugging and plugging in of pedals. They’re all available, all the time. Awesome.

I long searched for a send/return module that would meet all of my needs. It had to have stereo inputs and outputs, fairly small (because I knew I would need 9 or 10 of them), a way to control the send level, and a way to mix from 100% dry to 100% wet. There are several Eurorack send/return modules, but few are fully featured. After testing a couple, the one that fit the bill best is the Knob Farm Ferry. It has everything I was looking for. It can function in mono or in stereo, has send level (which also functions as a crossfader with a switch), mixes from full dry to full wet, and all in just 4hp. To top it off, the Ferry even includes the requisite TRS > Dual TS insert cables to connect your line level outboard effects and pedals. A nice set, I might add, and not something you’d find on Amazon for a couple bucks with generic plastic connectors and cheap cabling.

Since I have 10 pedals I wanted to use as FX with my synth, I knew I needed at least 9 Ferries. I already had a Strymon AA.1 that I was determined to use so I ordered 8 more Ferries in 3 separate batches. Knob Farm even sent me a free Ooots, a very excellent output module that I use with my satellite synth.

The modules themselves have been installed for a while, but I procrastinated fiercely with getting everything patched in. Patching in 10 separate pedals, all with stereo I/O (and some with MIDI) is quite the chore, and I was dreading it. I didn’t want a proverbial rat’s nest, which meant careful labeling and deliberate cable routing with lots of Velcro cable ties to keep things as orderly as possible.

Does it work?

Once I had everything patched in came the nit-picky task of testing. Are all the modules connected to their pedals correctly? Are all of the modules set up correctly for stereo sends and returns? We’re about to find out.

For this type of testing I’ve found that very simple sources work best. They’re easy to patch, and give good, regular feedback if something is amiss down the chain. Today I set up as simple a patch as I could muster: the “Final” output from Brenso into CUNSA being used in LPG mode, with an envelope from Falistri modulating the LPG, and the EOF gate striking the wavefolder of Brenso. Falistri was set to cycle at a fairly slow rate; about 72bpm. This gave me constant boings, with some space between to let the FX tell me whether they were working or not.

I manually patched that boing to each and every Ferry, and from each Ferry to my output module (Expert Sleepers ES-9), ensuring that everything was set correctly. All mono/stereo switches were set to stereo, the Gain/Xfade knob switches to gain. I then tested the wet/dry mixing, and gain of each. Of course I also took the time to ensure that the effects were working, and had some fun, particularly with the delays, despite such a monotonous source. It took about an hour, and although I ran into 2 separate problems (I had inputs and outputs mixed up on the Oto Bam and Boum), everything went about as smoothly as it could. Nice!

The FX are in, and now it’s time to jam.

Stereo Ping Pong Delay In Eurorack (and outside too!)

Ping Pong delay is easy, right? Just tick a box in a plugin, or flick a switch on your handy stereo delay unit and you’re done, right? Well, sure, but that’s all digital. What I’m talking about is ping pong delay, old school. Patching 2 mono, analog delay units in order to create ping pong delay in the stereo field.

When I first started thinking about how to do this, very few ideas came to mind. Of course there is the pseudo ping pong trick of setting one delay time at X with the other delay at 2X, which would give you a repeat on one side then the other. But that only works for exactly 1 repeat per channel. If there is any feedback, the first delay will sound again each time the second plays, which means it’s not really ping pong at all. It’s only kinda sorta ping pong. I wanted something better. The real McCoy.

As I started to research analog ping pong patching via Google, I was quickly dismayed. There aren’t really any good sources I could find to explain the method for patching ping pong delay. Nothing. Nada. After I couldn’t find the info I was after via research, I decided to ask. I asked on an audio engineer forum. Crickets. I asked a home studio group on Facebook and was met with “Just use a plugin. It sounds the same”, as if that’s a good answer to the question of how to patch analog hardware. I looked in my own studio recording books, which were all silent on the matter. It’s as if this information just doesn’t exist, or, more accurately, was outdated by the time the internet arrived, and the knowledge on how to perform this studio trick was simply never recorded digitally. It’s a lost art from the days of yore when everything had to be patched manually, and no one outside of studios used it. A voodoo spell that not even those inside of professional working studios seem to use any longer. Analog ping pong delay is dead.

After searching for what seemed like forever, I finally happed upon a video which explains using 2 analog delays in ping pong fashion, with the aid of a desktop mixer. The patch is fairly simple, even if it’s not intuitive.

Sound Source > Ch 1 input (panned center)
Ch 1 Aux Send > Delay 1 input
Delay 1 > split directly to Ch 2 input (panned hard left) and Delay 2 Input
Delay 2 > Ch 3 input (panned hard right)
Ch 3 Aux Send > Delay 1 input
Mixer Stereo Output

Be sure that both delays are set to the same time. Be extra sure that the feedback (repeats) for both delays are set to the minimum (1 repeat). The Aux Send of input 3 (Delay 2) controls the number of repeats. BEWARE: This is a feedback patch. It can get out of control very quickly. Use the Aux Send wisely.

But I don’t have a desktop mixer, and although they can be had inexpensively, I didn’t really have much use for one outside of wanting to do tape echo ping pong delay. I used to have a Xaoc Devices Praga in my eurorack synth, which would have been ideal, but I sold it in favor of decentralized mixing alongside using a matrix mixer. Hmmmm….

A matrix mixer is nothing if not a set of inputs, sends and returns. “I think I can make this work, even in the context of my matrix mixer being full stereo”, I thought. And sure enough, after several drafts in my Notability folder for synth patching, and experimenting with dummy cable theory, I had a solid plan. I just didn’t know if it would work.

The theory with a matrix mixer is the same, but because mine is stereo, I had to use make clever use of some dummy cables in order to defeat L> R normalization at the inputs to ensure everything was in the correct channel at the outputs, while still having access to the dry and wet signals independently to mix their respective levels later in an output mixer. To mix the dry and wet in the matrix as it’s patched would leave the dry signal in the left channel only. No good.

Sound source > Input 1L, with dummy cable in 1R
Output AL/R > mono mixer > Delay 1
Delay 1 > Input 2L, with dummy cable in 2R
Output BL > Delay 2
Delay 2 > Input 3R, with a dummy cable in 3L (it is not necessary to use a dummy cable here, but I’m using one for consistency)
Output CL > Output Mixer (Pan Center)
Output DL/R > Output Mixer (Pan L/R respective, or use a stereo input)

Knobs with an X are fully CCW (off). Knobs with a green check are mixed to taste. Knob with the red check is controlling feedback for the repeats. BEWARE: Ch 3A is feedback from Delay 2 to Delay 1. It can easily run away out of control and blow your speakers, headphones, and/or ear drums. Use it sparingly.

This method also makes use of a separate mono mixer to act as a send for both the source and Delay 2 to Delay 1. It what helps make the magic happen. Without the mixer, I couldn’t get the source and Delay 2 to Delay 1 without getting channels mixed up. Everything must remain on discrete channels in the matrix. As a result of the several dummy cables, Ch A’s outputs are discrete channels being used in a dual mono setup rather than in stereo, with those signals being mixed separately before going to delay 1. It was the only way to accomplish the task of sending both the source and Delay 2 inputs to Delay 1 while keeping those signals unmixed and discrete inside of the matrix mixer for final output.

Heed the inputs and outputs used very closely. It seems a bit odd, but it ensures that the stereo field is intact and signals remain properly separated until the final output mix. Deviate at your own peril.

The dry output is from Ch C, with the wet stereo output from Ch D. Pan the Ch C output to the center, with Ch D being panned L/R respectively.

This patch can likely be simplified (and perhaps sound better as a result) by splitting the audio at the Delay 1 output rather than relying on the matrix mixer to send the output of Delay 1 to Delay 2. This experiment, however, is for another day.

Although I haven’t pondered the nitty gritty of this patch in a mono matrix mixer, I think it would likely be a better tool for the job, but my first inclination is that you would need 5 outputs, and not the standard 4.

Enjoy!

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