Linux Audio Plugin Development (LAPD)
Inphonik
Linux Audio developer interview with Mathieu Demange and William Lamy from Inphonik
This interview was conducted by Amadeus Paulussen in 2025.
I have been using and loving the RX950, an AD/DA converter plugin, for many years, long before I switched from macOS to Linux. Since then, the makers behind Inphonik have also introduced the legendary SP-1200 (drum) sample machine from E-mu as a plugin under the name RX1200. I am delighted to be able to talk to Mathieu Demange and William Lamy from Inphonik today.
Dear Mathieu, dear William, a UI designer and a programmer who share a passion for music, that sounds like a dream team to develop plugins together. Can you tell us a little bit about how you found each other and how you came to develop plugins together?
William: Thank you, Amadeus, for having us! You couldn't be more accurate about our dream collaboration. Mathieu and I connected through our shared passion for the Demoscene—a niche culture of creative enthusiasts who blend programming, graphics, and music.
This community constantly strives to exceed the performance of what we've come to expect from computers since the 1980s. We both embrace this culture that encourages us to pursue better, more optimized, and efficient results, aiming for jaw-dropping innovations whenever possible. Our shared references guide our work, allowing us to instinctively move in the same direction without needing to consult each other. It's a natural synergy that we often jokingly refer to as a “Bluetooth connection” binding us.
As a small team, you support an incredibly wide range of platforms and technologies with macOS, Windows, Linux, iOS/iPadOS as well as VST, AU, AAX, Reason and NKS. Is this a challenge for you, or are you so well organized in terms of development that this doesn't give you a headache?
Mathieu: Indeed, developing our projects presents significant technical challenges. However, certain frameworks greatly simplify cross-platform development. For us, JUCE allows us to target macOS, Windows, Linux, and iOS simultaneously, along with various plugin formats such as VST, VST3, AudioUnit, and AAX.
While NKS is an extension sitting on top of the VST plugin format that requires additional implementation work, this explains why not all our products are NKS-compatible yet. Similarly, MPE is a standard that requires specific implementation, which might not be appropriate for our entire product line.
The Rack Extension format is architecturally unique and requires using the proprietary (but now public) Rack Extension SDK from Reason Studios.
These diverse formats have led me to develop abstraction layers that enable me to implement the core DSP code once and then deploy it across the JUCE framework and the Rack Extension SDK.
I also wrote quite a lot of tools and utility classes to be able to handle GUI stuff in a plugin format agnostic way.
Are you thinking about supporting CLAP in the future as well?
Mathieu: Absolutely! The CLAP format is already on the JUCE development roadmap, so we anticipate being able to implement it as soon as the framework supports it. We're closely monitoring its specifications.
Is one of the platforms you support more important to you personally than others?
Mathieu: The Rack Extension SDK for Reason devices development is particularly significant to me, as it was my entry point into DSP programming “for musicians”. A major technical advantage of this format is its enforcement of best practices in audio development, maintaining a strict separation of concerns between signal processing and interface components. This architectural strategy, coupled with a superhardened and sandboxed runtime inside the hosts, helps avoid common implementation pitfalls.
I have a deep attachment to the virtual rack paradigm in the Reason ecosystem because it reflects the hardware setup I grew up with, influenced by my father's professional audio equipment.
Reason's instrument and effect modules feature hyperrealistic interfaces that are user-friendly. From the beginning, the Rack Extension specification emphasized the importance of high-quality graphical rendering. In fact, when we initiated development on RYM2612, a 3D model-based interface was a mandatory requirement. Ultimately, the Rack Extension format allowed us to focus solely on core functionality without needing to address OS-specific implementation details.
Are any of the platforms and/or technologies you support more intensive for you in terms of customer support than others?
Mathieu: Statistically, the macOS / Audio Unit combo typically presents a few edge cases we don’t encounter anywhere else. In contrast, the Rack Extension format offers the most consistent runtime environment, not surprisingly since it was developed after other plugin architectures and probably benefited from all the lessons learned with them.
What do you think of GPU Audio?
Mathieu: This approach is conceptually similar to the paradigm shift that GPU shader programming represented when it first emerged.
The ability to leverage the massively parallel architecture of GPUs—originally designed for 3D rendering—for audio processing is technically fascinating. While I haven't conducted performance benchmarks in this area yet, I'm closely monitoring the technology's evolution.
Are you thinking about experimenting with it in the future?
Mathieu: For our current product line, I don't see an immediate implementation benefit from GPU acceleration, as it would create a hardware requirement divide between systems with dedicated GPUs and more resource-constrained configurations, on which I want our software to perform optimally.
However, potential applications for GPU acceleration could theoretically include, e.g., increasing polyphony counts in synthesizers, implementing more complex acoustic space simulations, performing higher-order oversampling, and machine learning-based models, of course.
Nonetheless, we are in an exciting era, watching significant technical innovations unfold while simultaneously working with emulations of vintage hardware that influenced my early years.
How do you go about developing plugins? What does the work process look like between the two of you?
Mathieu: Before starting a new project, I conduct a feasibility analysis to ensure that the audio processing algorithms can be implemented efficiently and faithfully. Once this critical validation phase is complete, William can begin working on UI design, sound design, and marketing assets.
William: Early in development, we collaborated extensively on usability engineering. Interface design decisions can take weeks, as can testing and determining the optimal implementation approach. The level of results we aim to achieve can only be accomplished through our collaborative process. Fine-tuning the graphical details also requires close coordination between us. We are committed to investing significant development cycles into that final quality percentage, which often distinguishes good products from exceptional ones.
Our constant objective is operational simplicity, which necessitates finding appropriate technical compromises. We want our interfaces to be intuitive enough that users won't need to open the user manual. As a result, much of our work involves problem-solving, and our development philosophy often emphasizes “less is more.”
What is your stance on copy protection, and what do you think of third-party solutions such as PACE's iLok?
Mathieu: It's interesting to note that we didn't initially need to address this concern with the Rack Extension format, as Reason Studios managed the entire licensing infrastructure. However, when we began publishing VST versions of our plugins, we had to determine our DRM strategy. This decision came together quickly. Pragmatically speaking, I didn't have the budget (or time) to invest in a robust protection system at that stage, and this approach also didn't align with our development philosophy. Our primary goal was to release RX950 efficiently.
William: We spent approximately half an hour analyzing the technical and business considerations. We recognize that piracy circumvents most protection mechanisms and that, as software users ourselves, we find authentication requirements, serial number activation, and license management agents frustrating sometimes.
Our most effective response was to implement an accessible pricing structure.
We are aware that our plugins circulate through unauthorized distribution channels, but our competitive pricing encourages users to purchase legitimate licenses to support ongoing development and gain access to direct technical support and community interaction.
There are several well-known plugin manufacturers in France. Do you exchange ideas with them?
Mathieu: We've had productive technical discussions with Arturia, the leading French developer in this sector. Alongside smaller development studios like ours, we've exchanged valuable insights with Low-Hiss (creator of eSPi) and waveTracing (creator of SP950), who share the same love for retro-digital sound reproduction algorithms.
What are your favorite plugins from other manufacturers?
William: We particularly admire the Swedish company Reason Studios, which delivers exceptional instruments and effects with thoughtfully designed interfaces. Their recent Ripley delay processor exemplifies their ability to combine technical efficiency, sonic character, and intuitive operation.
Mathieu: I love Klevgrand, who showcases a distinctive approach in audio plugin development, in almost every aspect.
William: Arturia provides an impressive product ecosystem with technically sophisticated sound engines and high-quality visualization components. Their Analog Lab preset architecture is remarkably well-engineered and user-friendly.
Are you already thinking about new products?
Mathieu: We are currently developing a project of unprecedented technical complexity for our team, with features that are significantly more advanced than our previous implementations. We can't disclose details at the moment, but we are very excited about it!
Can you possibly already announce something or give an outlook on the future of Inphonik?
William: This new methodology opens up technical possibilities beyond the hardware instruments and effects we are currently analyzing. We look forward to sharing technical specifications soon.