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ST Modular has garnered acclaim for its DIY Eurorack Modules, which empower users to assemble personalized modular synthesizers using supplied PCBs and components they acquire themselves.

The array of modules available spans oscillators, filters, sequencers, mixers, LFOs, envelope generators, effects., but also desktop synthesizers and tools, each meticulously designed by ST Modular to offer exceptional versatility. These modules cater to an extensive range of sound manipulation and modulation possibilities.

The origin of these modules traces back to a personal hobby managed by an individual enthusiast. The expertise in electronics and circuit board construction essential for bringing these projects to life was acquired through a blend of book learning, hands-on breadboarding, and engaging conversations with fellow synthesizer enthusiasts. Until today, ST Modular is operated as a non-profit small business, utilizing all revenues to cover costs for prototyping new modules and synthesizers.

ST Modular doesn't directly sell its designs, but instead provides licenses to third parties for manufacturing and distribution. Alongside the sale of PCBs, panels, and DIY kits, certain partners of ST Modular also provide fully assembled modules.


Stefan Tretau

The S and T before Modular

Hey! I am Stefan — a multi-faceted individual acknowledged for my roles as a devoted father, a loving husband, and a passionate musician. My journey in the world of music commenced during the early 2000s, where I found myself captivated by the realm of electronic music. Armed with a selection of electronic instruments, including a TB303, MC307, Micro Modular, and Xbase09, I embarked on a creative exploration that would come to define my artistic identity.

In due course, my musical endeavors expanded beyond personal exploration. Live performances became an integral part of my artistic expression, and I successfully transitioned to releasing music on esteemed labels such as Heimatmelodie, Karmarouge, Fortek, Broque, and Night Drive, etching my presence into the electronic music landscape. Sometime around 2010, I took the step of founding my own label, ST RECORDS. The journey began with the vinyl release "Whatever Happened," and to this day, it remains the platform through which I share my music with the world.

Yet, my interests transcended performance and production, leading me down the path of curiosity. In 2015, a pivotal juncture in my journey arrived when I grasped the intricate mechanics behind sound generation, particularly concerning Schmitt Triggers and Operational Amplifiers. This understanding marked the genesis of a fresh chapter, propelling me into a phase of self-guided learning encompassing circuit board design, soldering techniques, and culminating in the construction of my first DIY effect pedals. The allure of the "do-it-yourself" ethos grew stronger, prompting me to deepen my knowledge, craft my own schematics, and experiment with prototypes on breadboards.

As my passion for modular synthesizers burgeoned, I embarked on a new venture in 2017 — designing my own Eurorack modules, such as "Switched", "Triple Tom", "Cyllene" and "Franz". The positive reception and subsequent demand from the DIY community inspired me to take the next step. Recognizing the enthusiasm for recreating these modules, I made front panels and circuit boards accessible through This marked the genesis of ST MODULAR, an endeavor driven not by commercial aspirations but by a desire to innovate within the modular synthesis landscape.

Unlike the usual practices in the industry, ST Modular is more about pursuing a personal artistic vision for me than fulfilling the wishes and ideas of others. I prioritize uncharted functionalities and distinctive designs, unfettered by market trends. This approach enables me to cater to my own artistic instincts while fostering a sense of community engagement among fellow enthusiasts.

ST Modular remains a project driven solely by passion, devoid of profit-oriented objectives. Witnessing individuals create music using modules I've conceived brings me immense satisfaction, encapsulating the essence of artistic camaraderie. The crux of my journey lies in the harmony of music, where notes and circuits converge to create a symphony that resonates beyond temporal confines.

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