The Infinite Sunbeam

Here’s a patch that features a module based on stuff originally by @stschoen and @robertsyrett - it’s a new Pattern Bank Sequencer that’s less limited in patterns but less fickle to dial in a particular beat. Each row gets a knob and allows you to choose between one of 32 possible options. I’m refining the design so that it can have a few extra features, but here’s what I have so far. This also features @robertsyrett’s West Cat Oscillator which is my new fav.j

Note: Pretty high CPU patch: 32% on my Macbook Pro. May not run on all machines. If it doesn’t run on your device, just try deleting some stuff, like the pad at the bottom of the patch and the drums.

The Infinite Sunbeam.audulus (1.4 MB)


Breaking up the pattern into 4 4-bit numbers is a nice way to give back some precise control while still having loads of generative possibilities.


I wish I could understand how this works, because it is so good. Man, I have a long road ahead of me before I will be able to just assemble something like this. I suppose if it were easy, everyone would be doing it or nobody would be interested in it. I spent a good hour pondering/researching analog modular synth and, specifically, the concept of the mux/demux in the sequencer (I think that is what it is, anyway?) last night, and I just don’t get what it does. Grrrrr…so frustrating! :confused:

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Thank you! I will explain it to you :slight_smile:

I don’t think so - it’s pretty simple, even though it looks complicated.

It is easy, it’s just a technique you have to practice. This is my own technique that I’ve come up with - there are others to discover and master too!

This is an easy one - the Mux or multiplexer switches between sequence values. So if you have an 8 step sequencer, it can have 8 knobs going into each input of the multiplexer. The multiplexer is a little weird since it starts on input 0 (read up on arrays if you want to know why), so to select “Step 1” the multiplexer needs an input of between 0 and 0.999… - to select “Step 2” it needs an input of 1-1.999…, and so on.

The demux or demultiplexer is there simply to act as a display. One of them displays which steps are active (in blue) and the other which is the current sequence step (red).

In short, a multiplexer distributes many inputs to one output (knobs to create a sequence), and a demultiplexer distributes one input to many outputs (an “on” message to turn on lights in order).

Now on to explaining the patch:

  1. The clock - this sets the master tempo for the song. It is the fastest beat you’ll hear in the song. It is a steady beat, and would be boring if everything was controlled by it, so I’m using the sequencer I built to create a more rhythmic pattern.
  2. The clock divider - this is the module just below the clock. It divides the incoming clock signal by 32, so every 32 pulses from the master clock, it pulses once. It does this by counting the number of pulses that come through, and once it gets to 32, it lets it pass through. I’m using it to reset all of the sequencers so they stay in sync with one another, and I’m also using it to ping the randomize input in the random chance sequencer. It’s also pinging a flipflop that is adjusting the pattern for the snare, so every 32 beats, the snare pattern changes. A flipflop is basically a clock divider that divides by 2, but it holds its on/off state, so it’s useful for things like this.
  3. The gate sequencer - this does basically what the clock divider does, but instead of counting the incoming clock pulses, it multiplies the incoming clock signal against a pattern of on (pass) and off (block) signals. This allows it to “mask” the incoming clock signal and create a beat.
  4. The random chance sequencer - this is creating the main melody line. It is a four-step sequencer, and every time its R or randomize input is pinged, there’s a chance that each step will be set to a new random note. By adjusting the random chance % controls, you can adjust how often or not often they change.
  5. The modulation to octave attenuate-offset - this translates the 0 to 1 sequencer signal into an octave signal. You adjust the lowest note with the bottom control and the range of notes (how many octaves) with the upper control.
  6. The quantizer - this snaps the otherwise untuned sequence to a scale to control the oscillator.
  7. The synth - this is just an oscillator that @robertsyrett made with 3 LFOs modulating some parameters at different speeds - doing this livens up your sound and keeps it from being too repetitive. Other LFOs are controlling the cutoff and envelope amount to the filter. There’s a VCA and effects afterwards - pretty standard subtractive synth that uses a West Coast-style VCO.
  8. Everything else - it’s just drums into a mixer with their own gate sequencers, and a pad at the bottom that is basically a copy of the synth above, except it only gets triggered every 64 beats (because its envelope is opened by the flipflop, which is dividing the already divided 32 beat clock). That’s another useful thing with the flipflop - it can hold a note and open an envelope in a way that a clock divider alone wouldn’t. There’s a control at the top to fade in the hi-hat sound over the course of 45 seconds after opening the patch (or resetting it with the blue button).

That’s the how of the patch - but the idea really is simple behind it: create a beat, use a slowly changing pad as a base, and create a melody on top of it.

I usually start with a melody, add a drum part underneath it, and then the pad to complete it, but you can do it however you want.

A lot of the “trick” of modular and the way many people compose with it is you have sequenced parts going all the time and you simply fade them up/down and/or mute them to add more flavor. LFOs help too to keep the sound moving.

Setting up the patch took maybe 10 minutes, but the actual composition and adjusting and adding of LFOs where I wanted them took another 45m-1h.

So if you’d like to start doing this yourself, I’d suggest first turning everything down on the mixer except the main melody synth. Adjust the speed and the pattern and the key of the quantizer and make it your own. Then start adding back the drums with different patterns - try using LFOs to change the patterns too, or clock dividers, or use a gateable sample & hold module. Then add back in the pad (make sure it’s in the same key as your melody) and try to get it to do something different. Maybe you want a rhythmic pad instead of a sweeping pad.

In short, the best way to figure out how it’s done is to just sit there and play with the patch yourself. No amount of studying online will help you figure it out, and short of me explaining it like this, exploring it and poking around is the best option. Keep in mind that if you select a module, all other connections not made to that module are dimmed, so you can see what it’s connected to. That will help a lot too!


That’s amazing, thank you so much for explaining that to me! I wanted to ask how to do it, but I figured you probably have a million better things to do than to explain a patch to me that I thought might be too complex for me at this stage, but I actually understood that and intend to do exactly what you just described. This is what I was hoping I could achieve on my own if I researched hard enough, but I was getting nowhere lol! This forum is an invaluable resource to avoid the frustration I feel constantly as I try to fumble through this application solo. Thanks again, Mark! :smile:

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Absolutely - I always have time to explain and answer questions! Never hesitate to ask. Q&As like this also become valuable resources for the lurkers :+1:

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As a general lurker this is an absolute unit of a thread. Thanks!

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@robertsyrett I glanced at this the other day, but had no time to reply. thanks for your reply as well. @biminiroad made a great explanation that walked me through how to work with that patch, and I am super grateful for that, but I am still a little hazy on how I would use that concept in a practical way, myself, even though I can now clearly see how it works. sometimes I need a couple examples to see things in the level of extra clarity I need, as I stare at the world through the mind equivalent of broken glasses :rofl:


Most sequencers in Audulus are based on mux/demux nodes.


Runs without a hitch on my fresh 6th Gen iOS 11.4 & crackled earlier today on my Air2 iOS 12 but isn’t on the second try.