It’s 2024’s newest Eurorack module from CHAIR, The Center for Haptic Audio Interaction Research. But the inspiration dates back to some 1970s magazines and analog signal processing theory. What you get is an amazing physical modeling resonator for patching that sounds extraordinary. In a world of sound-alike gear, this is just the sort of experimental sound approach we were promised for the future.

The original source material is Michael Gerzon’s writing in 1971 and 1972 Studio Sound – a concept for “synthetic stereo reverberation” in the analog domain. That was a largely speculative project, as Gerzon – the inventor of ambisonics – realized that early 70s parts made realizing the idea impractical.

What a difference five decades makes, then. With the help of a lot of math, Clemens Wegener and Max Neupert from CHAIR created a stereo reverb effect that feeds the signals into a “rotation matrix” – which in turn means you can adjust the angle for lots of cool sounds. That makes an ideal, unique resonator that’s perfect for physical modeling synthesis and for patching physical modeling sounds. You’ll soon be able to read about this in a soon-to-be-published, already-peer-reviewed article entitled “The Aliased Complex Oscillator as a Paradigm for Analog Physical Modeling Sound Synthesis” – and maybe more math later on. But you can hear the results right away. CHAIR is showing this at Superbooth, but CDM gets an exclusive early preview.

It’s modern analog – but doing what wasn’t possible with early 70s analog. And the sound…

Love the way this looks. As you see you get copious voltage control, positive and negative level controls for every CV amount, a flexible send/return architecture (with dry/wet controls), VCF and VCA sync (each with on/off), dual X and Y architecture for everything, and of course the essential 360-degree rotation knob. Plus there’s that gorgeous display visualization – see below.

Max sends the test rig, which also includes lots of the terrific GLISS (which I love, and am endlessly behind on reviewing but will write up the moment I return to Berlin).

And here’s how it sounds:

More soon…