World premiere: E-RM introduces Polygonal Synthesis

E-RM’s polygogo Eurorack module is the very first digital stereo oscillator to feature the brand-new Polygonal Synthesis technique, invented by E-RM founder Maximilian Rest and DSP specialist Christoph Hohnerlein. Based on complex two dimensional amplitude shaping of sine waves, the polygogo is a performance-oriented, high-quality instrument which allows you to explore fascinating sounds and shapes alike.

Thanks to the combination of Polygonal Synthesis, two internal modulation sources and a beefy, fully-analog overflow stage, the polygogo is capable of generating an extremely wide array of animated spectra. Its results range from lush drones, massive basses and fierce leads to glitch madness and even sounds reminiscent of acoustic instruments.

Its “single knob – single function” interface, created in collaboration with instrument designer Tatsuya Takahashi, makes the polygogo not only a terrific live performance synthesizer, but a great tool for meticulous sound design as well – no menus involved.

E-RM polygogo eurorack module showing a polygon of order 3 with slight FM modulation.

You’d like some visuals that match your creative sound explorations? – The polygogo can deliver! Just connect its X and Y outputs to a laser system, X/Y plotting visualizer or video modular and enjoy some intriguing, constantly moving and transforming shapes on an external screen. 

Details on the Instrument

Polygonal Synthesis is heavily centered around the interaction between user and polygonal object behind the OLED screen. Based on the number of vertices (order) and their displacement (teeth), the fundamental tone and the harmonic ratio are created. Rotational modulation (roll) pans the sound in the stereo field or acts as a vibrato. The internal linear FM operator (OP ratio / OP amt) can modulate the fundamental frequency and its high spectral content. An analog overflow stage at the output (fold) is able to act as a wave crusher – thus, it gives sounds the finishing touch right in front of the output (X/Y).

All main parameters are accessible via sliders. For fine-tuning and to give sounds some additional tweaks, potentiometers were added. Control voltages can be used to modulate each and every parameter. With a cable plugged into one of the CV inputs, the corresponding potentiometer turns into an attenuator respectively attenuverter. Push buttons allow you to choose between three modes of operation. In detail, there are “Infinite Cycling”, “quantized Order” and “stepped OP ratio”. Last but not least, a hard sync input is available.

Polygogo from E-RM Erfindungsbüro

Polygogo from E-RM Erfindungsbüro – captured at Superbooth 2019; Valhalla DSP added

Gepostet von Loopop am Montag, 13. Mai 2019

• E-RM Polygonal Synthesis technique
• 384 kHz internal sample rate
• 24 bit / 96 kHz stereo output
• High contrast OLED interface
• Six performance sliders for all main parameters
• Eight fine tune potentiometers / precision attenuators respectively attenuverters
• Three push buttons with LED feedback for selecting a mode of operation

 Sound shaping parameters and their control elements

• Pitch (slider, potentiometer)
• Order (slider, potentiometer)
• Teeth (slider, potentiometer)
• Roll (slider, potentiometer)
• Operator Ratio (slider, potentiometer)
• Operator Amount (slider, potentiometer)
• Exponential FM Input (potentiometer)
• Fold (potentiometer)


• High speed V/oct and exponential FM inputs (24 bit / 96 kHz)
• Six actively filtered CV inputs (16 bit / 6 kHz)
• One trigger input for hard sync


• 3U Eurorack module, 32 HP wide, 26 mm in depth
• 110 mA @ +12 V
• 15 mA @ -12 V
• Weight: 266 g

Availability and Price

The polygogo Eurorack module will be available in Winter 2019.
MSRP is 539,- € incl. VAT.