Funkstern Plus

Funkstern Plus

Parallel to the design of musical instruments and kits, workshops and concerts, I have realized commissions for museums, artists and ensembles in recent years - for example automatic curtains for the exhibition Magic Machines (Netzwerk Medienkunst at Technische Sammlungen Dresden), soil microphones for Patterns of Paradyze (Festspielhaus Hellerau) or the development of the technology for the self-sufficient outdoor sound installation Paradiesplatz – Das Innere. They were all created in 2022.
Here now are insights into the development of the radio art object Funkstern Plus, which was commissioned by the Rundfunkorchestra (at this time


In the fall of '21, all signs in Saxony were pointing towards another Corona Lockdown. In those unpromising days, I was invited for a small residency at the Medienkulturzentrum Dresden. At that time, Konrad Behr, a member of the Rundfunkorchestra, asked me to help create a museum piece. The ensemble had won the "Born To Be Bauhaus" prize from the Bauhaus University Weimar for its unique live performances with sound collages made from radio material. As part of the prize, in turn, a work of art was to be given to the university's collection "Archiv der Moderne".
From the originally simple idea of an FM transmitter that feeds sounds of the orchestra members into the near-field radio, we jointly developed a modular construction with extended possibilities. The heart of the system is a 7-channel stereo mixer with direct FM transmission via the built-in antenna.
The concept of modularity also offers the possibility to use it in different constellations for the orchestra's live performances. Thus, the audience can listen to the sounds played via their own smartphones or radios set up in the room. For the museum object, we have developed modules with audio players and a synthesizer with light sensors, which can also be used as instruments for the live performances.
Here are a few technical details:

Radio base:


  • Mixer with 7 adjustable stereo input channels.
  • Either one stereo or two mono jacks (6.35mm) can be connected.
  • Channel 1 can be switched to output for monitoring or recording purposes.
  • Adjustable master volume with 7-segment LED display.
  • The sum is forwarded to the FM transmitter. This transmits directly into the room via the antenna. The transmit power is adjustable.
  • Built with Adafruit Si4713 Breakout Board and a Teensy LC as controller.
  • The transmitting power is adjustable up to 50nW and is sufficient for approx. 10m.
  • RDS radio identification
  • FM frequency can be changed by software
  • Power supply via 5V USB

Player modules:


  • Connected directly to the mixer via 6.35mm jack plug.
  • 7-segment LED display
  • Plays endless audio from Micro SD card
  • Built with Teensy 4.0 and Teensy audio adapter
  • Powered by a link from the base module
  • Can also be used stand-alone when connected directly to Teensy micro USB port

Synth module:

  • Technically almost identical to the player module
  • 3 additional light dependent resistors (LDRs) as sensors.
  • Different synths can be programmed
  • We decided to use an FM synth with sine waves.
  • Tones are then only generated when the amount of light near the synth changes.
  • The module calibrates itself constantly by a software routine. Light variations over a longer period of time (e.g. day and night or gathering clouds) have no influence.

Since the even arrangement of 7 modules in a circle results in a very odd angle (360° / 7 = 51.42857°), the design was not directly possible with my preferred PCB editor KiCAD. So all PCB designs had to be drawn by hand in Inkscape and later exported with the (great) plugin SVG2Shenzhen.



After several weeks and months of planning, designing and manufacturing, the Funkstern Plus was born.



For a variety of reasons, all related to the Corona pandemic, the final exhibition of the residency at the Medienkulturzentrum was postponed three times. This in turn resulted in the opportunity to present the now completed object for the first time with a concert at the finissage at the end of March '22.
That evening the Rundfunkorchestra created a concentrated, magical atmosphere. Radios scattered around the room played sparkling sounds and there was a live jam (NINJAM) with an orchestra member in Ankara /Turkey. Another part of the setting were room-filling video projections, as well as the playing of a piano string installation with violin bows by artists of the orchestra. The instrument, stretched over an entire wall, was part of the exhibition Echoes, which, however, is a completely different story.... (Teaser @youtube).



Since then the orchestra has played several concerts with the Funkstern Plus - e.g. here in September '22 for Radio Art Zone in Esch /Luxembourg.

Update 11/23: After a very spontaneous application, the Rundfunkorchestra and noisio were awarded the Sächsischer Staatspreis 2023 for Design for the Funkstern Plus in the category Digital Design . WHOA!!
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