Guest post: Blue Nautilus on creating Acidus Versio

Today, we chat with Blue Nautilus, the creator of the Acidus Versio firmware developed using the open-source tools available for Versio. Read on to learn about his inspirations, development process, and how Acidus Versio evolved. 

What’s your musical background?

I had some piano lessons as a kid and self-taught guitar in college, but my only formal music training came later in life when I was in graduate school and I started learning north Indian classical music. I trained on sitar as an apprentice to an Indian master for 5 or 6 years. That experience really taught me about the power of practice, the connection between expertly learned motor control and the fidelity of expression, and about the complex interrelationships between music and culture. Some of my VCV Rack modules have attempted to implement the sounds of Indian classical music. 

How did you get into modular?

I took one step onto the slippery slope with a semi-modular Moog system and the rest is history. The allure of the patch cables was something I couldn’t resist, and the perfect intermixing of technology and music just completely sucked me in. 

What inspired you to create this firmware?

I have always loved the idea that a piece of hardware in the rack could serve many different purposes depending on your current needs. One of my first modules was an Ornament & Crime, and whenever a new function came up that I didn’t have a module for, O_C was there to become that function. So the Versio platform seemed like the perfect extension of this idea. 

I had been playing around with the Daisy platform as a sandbox for testing out ideas that I had for my own modules, which I develop under the brand Seaside Modular. I had made some VCV rack versions of these modules and wanted to get my hands on them in the real world. I realized that the Versio could be a way to test some of the ideas in hardware before designing and building custom hardware for these projects. In 2022, I built a version of my generative sequencer, Proteus, for the Versio platform. This wasn’t intended really for anyone else to use, it was just a way to test some things, and for me to get familiar with coding for the Daisy. 

So I was already familiar with coding for the Versio when I started to discover the sounds of 90s acid house. I know I’m kind of… a bit late to the game with this. But like a 90’s musician finding a 303 in a thrift store, I was dusting off these old tracks and appreciating this sound for the first time in the early 2020s. I started to test out the dedicated 303 modules that existed at the time for eurorack and also to delve into the amazingly detailed analysis that exists of this synth’s circuitry and all of its quirks. That’s when I discovered Open303, a codebase written by Robin Schmidt that implements what aims to be a painstakingly accurate simulation of the Roland TB-303. 

Given that this software existed already, the quickest way to turn it into usable hardware was to use an existing, accessible platform. I began to wonder if Open303 could be adapted to the Versio. 

The entire codebase, however, was just too much for the little tiny embedded system that is the Daisy Seed. I decided to start hacking pieces out, and the first thing to go was the sequencer. The Versio could be stretched from its roots as an effects platform to be a sound source, but it wasn’t going to easily implement a sequencer. So I took out the sequencer and a few other things, and made it fit. And thus was born Acidus Versio. 

Did the firmware end up evolving beyond your original idea?

Since the code is open source, some other people have taken up the mantle of improving it. This is just more evidence of the great collaborative spirit of the modular community that the Versio platform has played a role in stimulating. For instance, Jeremy Blake aka Red Means Recording, took an interest in it, and made some adjustments to the sound and to the parameterization. I certainly didn’t anticipate the level of interest it got, but I think that’s just that I underestimated how much craving there is still for that specific sound. 

What part of the firmware are you personally most proud of?

That it works and kinda sounds enough like a 303 that people enjoy playing with it!

I did also like that I used the Versio’s toggle switch to allow the user to switch between several different sets of parameter ranges; one that mimics the original synth, one that replicates the famous “Devilfish” mods, and then of course there’s Synthdad Mode, which implements a suggestion that Youtuber Synthdad made while testing it.  

What tools, languages, or workflows did you use during development?

It’s written in C++ and relies on libDaisy, but this was a port and not code that I wrote from scratch myself, so it was an unusual experience for me. I had to understand what someone else had done enough to be able to modify it. 

Do you have any advice for people interested in creating their own firmware?

Just jump right in. Trial and error is the core of development. I recommend starting with some existing code (there are plenty of open source Versio firmwares out there), and just start changing things and seeing what happens! As far as I know you really can’t permanently brick the module with firmware, so there’s nothing to lose. 

Where can people download it or learn more about it?

You can download the firmware and find the manual at the github page.

I made a video about developing it, where I physically modified a Versio as well to have the original 303 knobs:

Red Means Recording also made a video on it.

You can find more from Blue Nautilus on YouTube, Instagram, and his website.