Daisy in the Wild: XTRIKE

XTRIKE is an upcoming Daisy-powered wavetable synthesizer and workstation designed for musicians to explore sounds and perform dynamically using its large onboard drum pad and magnetic tactile controller.

Musicians can sound design with its internal wavetable synthesis engine and trigger notes by hitting the velocity-sensitive pad surface with their fingers or drum stick. They can also expressively alter the triggered sounds using the magnetic bend controller.

X Audio Systems, based in Torino, Italy, is dedicated to designing instruments that inspire creativity. Their emphasis on sonic exploration is evident in their current lineup, Beats FM and VCRadio, which both allow musicians to manipulate incoming audio from the onboard FM/AM/SW radio receiver. We spoke with Charles from X Audio Systems to learn more about XTRIKE.

Interview with Charles Bisaillon

ES - We would like to start this interview by getting to know you better and learning about your background in music and synth development.

CB - My name is Charles. I’m Canadian, but I’ve been living in Italy for many years with my family. My passion for musical instruments started at a very early age, initially with acoustic instruments and gradually shifting toward electronic devices. I graduated in electronic engineering in 2008, but life had other career plans for me and I’ve never worked in that field. So, music production and synth building remained a part-time hobby for years.

Then in 2020, the pandemic came along. It shattered what I had built and relied on. That’s when I knew I had to invent something new, and the BEATS FM was born. This strange and unusual musical instrument generated a lot of hype online and resonated throughout social media. So, the X Audio Systems team was formed and the instrument went into production.

Today, X Audio Systems is a team of 7 people passionate about electronics and audio devices. Our objective is to provide musicians worldwide with innovative ways to compose, perform and produce music. We love to explore the unknown!

ES - We would love to hear more about the inspiration behind XTRIKE. What kickstarted this project?

CB - XTRIKE is the result of many years of experimentation with different synthesizers, electronic drums and signal processors. Our aim was to develop the most intuitive user interface for musicians of all backgrounds, including non-musicians. So we sat down and thought about it. Soon, we all agreed that finger-drumming is probably the most intuitive approach to music, although maybe a little bit too simple (some would say). But the idea was fresh and innovative and we decided to get the project started with a piezo element, where we could map the velocity (how hard we hit the piezo) to just about any parameter (and there are a lot of parameters).

And a new synthesizer was born out of this innovative, over-simplified approach.

ES - What has the developmental process been like?

CB - The first mono prototype was made on a breadboard, plus a PCB board with a piezo element glued underneath. The responsiveness of the interface was amazing! We had a very precise sensor, with a large range and very low latency. It was so much fun to play with.

Programming was a lot a fun as well, There a lots of free libraries to work with, some of them sound really nice. So we worked with a combination of free libraries and some other functions that we made ourselves, like the stereo wavetable engine for example. We ended up implementing so many functions and used so much processing power that a single daisy couldn’t handle it anymore. The problem was mainly linked to the processing power required to run the sound and the display smoothly, while raising the number of voices. So for the second prototype we switched to a dual-daisy approach.

But for us, the most difficult aspect of synth creation remains the mechanical part: the faceplate, the backplate, the PCB production, etc. It’s important to work with reliable suppliers to get professional results. Furthermore, it’s very improbable to get everything right on the first run. There’s always something that was overlooked or something that changed over time. So we adjust it and go for a second run, or a 3rd, until we have a nice professional unit.

ES - XTRIKE's key features include the large velocity-sensitive pad surface and the magnetic bender. What was your motivation and goal in creating a tactile instrument?

CB - The motivation for a tactile instrument comes from the fact that I find myself finger- drumming on just about any surfaces during the day. It feels so natural to follow a beat with your fingers, like playing along with the car’s turn signal click, for example.

So, the pad was projected to trigger sound on very small vibrations and to be very responsive to touch (although the responsiveness can be adjusted). The instrument was designed with a percussive approach in mind, but soon became a complete synth with a powerful auto-tuning and micro-tuning engine. Basically, you can play different notes and musical scales (you can also make your own scales), depending on how hard you hit the pad. “Velocity to pitch” sounds like a crazy idea, but actually when combined with auto- tuning and micro-tuning, it opens a whole world of possibilities.

The human to machine interface is one of the main drivers behind the creative process. So, our main focus in developing the 3rd revision is to concentrate our efforts on a new pad that will combine enhanced responsiveness and playability. We want to give the musician something more than just a velocity parameter, but without compromising the soul of the instrument. That’s what we’re working on right now.

ES - The magnetic bender looks fun to play with! It's quite different from a conventional pitch wheel. We are curious to hear how you came up with the design.

CB - The magnetic bender is unique. It uses opposing magnets to create resistance to displacement and to precisely balance the centre point. It’s fast, precise and in permanent equilibrium. The only mechanical contact inside the bender are the 2 ball-bearings, so the tactile experience is the smoothest it can be. An analog Hall effect sensor was then carefully positioned inside the magnetic cluster to harness the field’s displacements and use it to control a range of different parameters.

So we produced circa 15 different version of the 3D printed designs, until we were satisfied with the results. It was very difficult to position the Hall sensor inside the complex magnetic fields, they are constantly stretching and compressing according to bender displacement. We didn’t have the mathematical knowledge to calculate the optimum position, so we ended up making a lot of tests and a lot of mistakes before getting satisfying results.

ES - Micro-tuning, still a rare feature in synthesizers, is also a key aspect of this instrument. We would love to hear your experience with microtonal music and why you chose to incorporate it into XTRIKE.

CB - Only few synthesizers today give you the possibility to use micro-tuning. Sometimes musicians like to break the rules. Some other musicians like to play music according to their own cultural background, sometimes with different scales. We feel that the 12-tone per octave system works great for playing a number of musical genres, but is somewhat limited for experimental and non-western music producers. Basically, we didn’t like the idea of speaking only one language in a multicultural world.

When XTRIKE is in auto-tune mode, octaves are divided in 24 tones (instead of 12). This means that there’s a new note in between every note. Technically, every tone can be pitched up, or down, by 50 cents. The micro-tuning also works great when playing a MIDI keyboard, XTRIKE becomes an exotic music production device, instantly diving in Middle Eastern or Asian musical universes.

ES - What drew you to the Daisy platform for developing XTRIKE?

CB - XTRIKE is a project that started early 2024 after watching Takumi’s inspiring videos for beginners with the Daisy Seed. I already had decent experience in C++ and Swift languages, so I decided to give it a try. The first objectives were really easy to reach and I really enjoyed working with a complete system that required minimum external components to get results.

From the first day, the Daisy platform has delivered amazing performance, stability, reliability and flexibility. There are many assignable pins, which makes it a great choice for experimenting and also for more complex projects. There are different memory types and regions that offers a lot of flexibility. Also, it’s a great tool for education, it’s almost like a plug and play device, so you can start programming right away with a large number of libraries. In few words, I got hooked.

ES - We are intrigued to learn that this synth is powered by two Daisy Seeds! Could you tell us more about that?

CB - Because of XTRIKE’s percussive interface, having low latency has been a key element in the design process. Piezo elements have practically no latency, but XTRIKE requires massive processing power to operate 4 simultaneous voices with a number of effects and there are so many mathematical operations to complete. So, even though the daisy seed is a very powerful platform, it has its limits, and a dual-daisy approach was necessary to get the results we were aiming for. Even if that meant raising production costs.

The first Daisy Seed handles the 4 voices, the tuning engine, the sequencer, MIDI and all the controls. The second Daisy Seed handles the looper, the display and all the stereo DSP effects (synth and loop). A communication protocol was implemented so that both daisy could talk to each other and work hand in hand. This approach solved the latency problem for both the sound and the display. There’s probably even some margin left for further development (like raising the number of voices and adding new functions), if we can succeed in optimising our code to harness more of that processing power.

ES - What's next for XTRIKE? We would love to hear about your design plans as the prototype moves toward a final version.

CB - XTRIKE is still in development and the prototype is in pre-launch on Indiegogo.

The project should be ready for the official launch by the end of the summer 2025, or early fall. The architecture is very solid and the dual-daisy approach is delivering amazing results. From a programming point of view, the instrument is almost ready.

But before moving to the production phase, most of our efforts are concentrated on the mechanical interface, with major attention on the tactile pad. The pad is getting a complete overhaul, it’s being redesigned to be much more receptive to human expression, concentrating our focus on sensitivity and playability. The new pad will be mechanically isolated and available in different colours.

Furthermore, thanks to all the comments received online, we came up with a solution to adapt the instrument to a larger number of musicians. For now, we’ll just say that we’re working on a dual-function tactile pad. The goal is to get musicians (or non-musicians) to have the most simple and intuitive interface to play with, so to enhance their creative process.

Conclusion

It's wonderful to hear how much joy and excitement the X Audio Systems team is experiencing while developing XTRIKE. This will surely result in a new instrument that offers musicians a tactile and fun way to explore sonic and tonal possibilities.

If you're interested in keeping updated about XTRIKE, check out the Indiegogo page as well as Charles's Instagram and YouTube accounts.

XTRIKE TEAM
Charles Bisaillon - concept, circuit design, programming, testing, and communications
Francesco Mulassano - design, testing, and communications
Lorenzo Tanci - circuit design, programming, and testing
Alessandro Comanzo - circuit design and testing
Claudio Carando - prototyping and design
Luca Baù - testing and communications
Sébastien Jacques - testing and communications