Make Noise Plexiphon, super tempting!

After my last few nights re-engaging with the Morphagene, and remembering the introduction of the Make Noise Plexiphon at Superbooth 2026 marking another significant chapter in the ongoing collaboration between Make Noise, and Tom Erbe of Soundhack. It got me looking at the Plexiphon, which is billed as a "stereo modeless spatial texturiser", the Plexiphon occupies the notoriously difficult-to-tame territory between a multi-tap delay, and a dense reverberation.

For those familiar with Erbe's previous DSP architecture, such as the Erbe-Verb or the Mimeophon, the Plexiphon represents a genuinely fresh hardware start rather than a sequel. At 16HP, it offers a fascinating proposition for any Eurorack system: a continuous, fully voltage-controllable sonic space that treats time, and reflection, as fluid concepts.

The End of Algorithmic Isolationism

The most striking aspect of the Plexiphon's design philosophy is what is missing from the front panel: there are no mode switches, no preset wheels, and no discrete algorithms to toggle between. Classic effects processors traditionally force you to choose between a 'Hall', 'Shimmer', or 'Tape Delay' mode. The Plexiphon eschews this entirely.

Instead, it asks you to navigate a continuous spatial topography where every parameter can be modulated simultaneously. A slow LFO does not crossfade between two fixed states; it organically reshapes the architecture of the space itself.

Architecture of Space: Plexus and Size

Two primary parameters govern the core geometry of the effect:

• Plexus: This control dictates the number of internal feedback paths and the degree to which they are tangled together. At low settings, the module produces clearly articulated, discrete delay taps. As you increase the Plexus value, these taps multiply and weave into a dense, continuous wash of sound.
• Size: This parameter establishes the temporal relationship between those feedback paths. Its behaviour is contextual. When Plexus is low, Size acts much like a classic delay time control. When Plexus is high, it dictates the perceived dimensions of the reverberant room.

This interplay allows for incredibly expressive modulation. Driving these parameters with complex CV, such as a chaotic source or an irregular sequence, yields filter-like movement; and spatial smearing that blurs the line between rhythmic echo, and ambient wash. Pushed to its extremes, the architecture even lends itself to aggressive, Karplus-Strong style physical modelling tones.

Timbral Shaping and the Stereo Field

To sculpt the texture of the echoes, the module features Diffuse, and Color, parameters. These allow you to push the reflections from soft to sharp, and from bright to dark, taming the high-frequency content of the feedback loop as it decays...

However, the Plexiphon truly excels in its manipulation of the stereo image:

• Couple: This determines how isolated or intermingled the left and right channels are, allowing you to fluidly shift from dual-mono processing to a fully interlaced, complex stereo image.
• Skew: This applies opposite or linked changes to the Plexus, Size, and Color parameters across the left and right sides. A single CV input here can pull the right channel towards a long, bright reverberation whilst simultaneously tightening and darkening the left channel.

The Envelope Follower: A Patching Centrepiece

A highly considered detail that elevates the Plexiphon from a standard end-of-chain effect to an integrated synthesis tool is the inclusion of a dedicated CV output. This jack provides an envelope follower signal derived directly from the audio input.

This opens up deep patching possibilities. You can patch the envelope follower back into the Plexiphon's own Diffuse or Size inputs to create ducking reverbs or dynamics-driven room expansions. Alternatively, you can route it elsewhere in your system to drive a VCA, open a filter, or modulate an LFO rate in time with the spatial trails.

Final Thoughts...

The Make Noise Plexiphon is not designed to be a "set and forget" reverberation unit. It is an instrument designed to be played, sequenced, and heavily modulated. By abandoning rigid algorithmic boundaries in favour of a fluid, continuous spatial processor, Tom Erbe, and Make Noise, have created a module that seems it will reward curiosity, and complex patching. As a person always looking to explore the fringes of time-based processing, and dynamic spatial textures, it is undeniably very tempting....