ADDAC System - Swell Physics Review
Ever wondered how you could use waves in modular synths?
Modular synths are so cool! For me, the most exciting part about the Eurorack modules world is that you can see any completely out-of-the-box idea come to life. Module manufacturers truly push the boundaries of electronic synthesis into uncharted territories and they’re not afraid to create designs that are not following any conventional paths.
One of those brands is definitely ADDAC System. I’ve had the chance to try one of their latest modules called Swell Physics and I can honestly tell you it’s been a very exciting journey exploring it and finding ways to implement it to my patches. Swell Physics tries to emulate the movement of waves in the ocean and creates CV signals that move freely depending on the parameters you set. It might sound like something too sophisticated and hard to fully wrap your head around it but, in reality, it’s not that complex - and it’s certainly fun. In any case, that’s the fun part of having a modular synth. You can experiment and explore modules by patching without really having to fully understand how they work!
Overview and Controls
Right out of the box, you’ll immediately see that Swell Physics is a very well made module. It’s beautifully built, everything is clearly labeled, and both the knobs and the patch connections feel great. It is a 10HP module which is probably the golden standard for having enough controls and features without being too big for your case and has quite a few knobs, switches, and a lot of connections.
The concept of the module as ADDAC System explains it, is to think of the 4 CV signals that have separate outputs on the bottom of the module are like four buoys that are traveling in the ocean. You can then control the spacing & speed of their movement, the height of the waves by using the knobs, or even agitate the water to make things more complex! The naming of this module - Swell Physics - is so to the point as the signals coming out of it are swelling in and out just like waves do. You can even replicate wave sounds by using noise and swell physics and you’ll be instantly transferred next to the ocean!
If you sit and read the manual like I did, you’ll be amazed at how they scientifically recreated this natural phenomenon of 4 little buoys sailing to the sea. I won’t go too much on the science behind it but, instead, I’ll try to explain every function in very simple terms to make it easier to understand what it can do and how you can control it.
Knobs & Switches
On the top part of the module, there are 6 knobs, 3 switches, and 10 little lights that give you a visual representation of what’s happening inside.
Swell Size: This knob controls how big the waves are which translates into voltage. The bigger the waves - the more the voltage coming out of the outputs.
Agitation: Agitation makes the signal go from smooth to more abrupt with little spikes of voltage as you increase it. The more agitated the water is, the more unpredictable it gets.
Spread: With spread, you can increase or decrease the distance between the 4 signals. So if you increase the spread it will take more time for the signal to go from output 1 to 2 etc.
Simulation Speed: The Sim. Speed is very similar to the frequency of an LFO. It determines how fast each cycle will happen.
Offet and Output Gain: With the last two knobs, you can set the signal to any voltage between -+5V or 0 to +10V
Now for the three switches. The -+/+ switch will set the module to either -+5V or 0 to +10V. It essentially allows you to have bipolar or positive modulation. The bottom switch will just change whether the CV input for Offset and Output gain will affect the Offset or the Output Gain knob. Lastly, the middle switch changes the module’s mode. There are two modes - Scrolling or Evolving Mode. I’ll do my best to explain the difference between these two modes. Essentially the difference between them is that in Scrolling mode, the buoys are moving independently while in the Evolving Mode, they affect each other. Imagine having the 4 signals running on their own or being tied to an invisible string that makes each other react to the movement of the closest one.
Lastly, there are CV inputs for all top four knobs and one shared CV input for Offest/ Gain. The top four CV inputs also have a dedicated attenuverter which is always handy!
I also have to mention that there are also 3 additional outputs on Swell Physics. There are two outputs for Gates and one that outputs the Average value of all 4 CV outputs. Gate 1<2 outputs a Gate whenever output 1 is lower than output 2 and Gate 3>4 outputs a Gate whenever output 3 is bigger than output 4.
Overall Experience
Ok, enough with the technical specs. When I first heard of this module and didn’t really know what it would do, I must admit I thought it would be something like an auto-swell for incoming signals. More of an effect rather than a modulation module. But it has nothing to do with that. My first couple of days were, as always, spent trying to figure out everything myself without reading the manual. This is something I always do to understand how intuitive a module or any other piece of gear is. So, for example, using the CV outputs to modulate Filters immediately works and you start to get some movement going. Just by tweaking the knobs, you can understand what is happening if you use it with something that is clearly audible like a Filter’s Cutoff so I didn’t have any trouble understanding it by myself.
The very random and constantly moving nature of this module makes you think of ways to best utilize it. I’ll share a few patch examples below that I think shine by using Swell Physics. It is definitely not your standard modulation module like an LFO would be. You can of course use it like you would use an LFO and just modulate a few parameters on your modular synth and just let it do its thing. Using the example with the Filter’s Cutoff I mentioned before, you can just take its outputs and modulate your Filters’ Cutoff points and make them move around in a relatively random manner which is great!
But as soon as you realize that all 4 outputs are somewhat connected, it will spark even more ideas. I really like finding ways to use all four of the CV outputs in the same patch and make it revolve around this module. I think that it makes it way more interesting and Swell Physics really stand out more this way. It’s definitely a more ambient-friendly module, especially at slower speeds. That in-and-out fading that you get is perfect for creating movement and leaving room for your sounds to breathe and have their moments. I’ve used it quite a lot for pads and more sustained sounds to emphasize on its swelling characteristic but also for bringing melodies in and out of the mix.
The light indicators on the top are also very useful since you can see which signal is active and if it’s positive or negative and you also have a visual indication for when the Gates are triggered. I’ll be honest and say that I haven’t used the Gate outputs that much other than triggering a voice’s envelope but I’m sure I’ll find a way to utilize them more in the future.
Patch Ideas!
To get a better idea of what you can do, I have a couple of patch ideas I’ve worked on with Swell Physics. And I can definitely say that patch idea no. 2 is one of my favorite patches ever made on a modular synth!
Ambient Melodies
Our first example is pretty simple. Here I use Swell Physics to control the amplitude of 4 oscillators. To make this musical, I played a sequence on all four oscillators from the KeyStep Pro Chroma and let Swell Physics decide when each melody from each oscillator will appear in the mix.
You patch the outputs of Swell Physics to the CV inputs of your VCA where each voice is in and let it work similar to an envelope!
You can still play your melodies or sequences but by using Swell Physics those same melodies will be drastically changes since each part will be heard at a certain point the module decides.
It will also happen in a swelling manner which is very pleasing and it can transform a repeating pattern into something more interesting and exciting. Then you can feely mess with Swell Physics parameters and find your sweet spot!
This is a great way to mix a few voices together and introduce randomness to their mix. The difference this makes compared to triggering each voice alongside each Pitch CV is so big you have to hear it to appreciate it!
Floating Modulation
This was my favorite patch so far! When it comes to LFOs, I really love it when I can fade them in and out so I thought I could use Swell Physics to do exactly that since most LFOs don’t have this built-in.
Here, I’m using 4 LFOs from øchd and I’m patching them in a VCA to attenuate them. Then I’m taking the outputs of Swell Physics and patch them in the CV inputs of the VCA to control when the LFO is on and when it’s not. You can now take the outputs of the VCA and patch it to Filters, Effects, or anything you want to modulate with them!
So now instead of having a constant LFO modulating a parameter, you can instead have Swell Physics bringing the modulation in and out for you. I tried that with the Filter Cutoffs of 4 oscillators playing their own melody at the same time and the patch became so much better!
The unpredictability of when the modulation is going to appear is really fun and will results on a new sequence every single time!
Conclusion
I really enjoy having such a unique module in my case. Swell Physics is not just an innovative idea but it’s also so well executed! You have absolute control over what’s going on, you get some visual feedback, and you can also modulate the module in various ways. My introduction to ADDAC System could not be better and I’m looking forward to the next module I’ll add to my modular synth.
It’s one of the modules that will make your modular synth stand out and differentiate it from being a glorified synth that could have been a pre-built synthesizer (and would cost 1/10 of what you paid). Swell Physics takes a concept from the real world and translates it into a Eurorack Module in such an elegant and useful way. It might not be the module you’ll use on every single patch but when you do include it - it will make a huge difference and will elevate your patch to a whole new level.
If you’re looking for something totally fresh and mysterious, make sure to check out Swell Physics and all the other modules ADDAC System created. You will definitely have a ton of fun using this one and your patches will be floating and beautiful like sailing through the ocean!
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