Superbooth 2025: AJH Synth Matrix VCF squeezes the 16 Oberheim Matrix filter modes into a module, and doubles them up with Polivoks spice.
Filters are essential sound shapers in subtractive synthesis. Moog, Roland, Oberheim, Korg, Steiner Park… each filter circuit has its own characteristics and sound. The Oberheim Matrix polysynth from 1984 offered one of the most comprehensive analog filter circuits, as it housed 15 different modes.
In Eurorack, we have almost all filters, but one was missing until now. Yes, the big one by Tom Oberheim. For Superbooth 2025, AJH Synth has released the Matrix VCF, a new filter module that brings this mighty filter to modular systems in an upgraded version.
AJH Synth Matrix VCF
Classic filters usually have one mode (lowpass), or a maximum of four or five if they have a multimode characteristic. In the case of the new AJH Synth Matrix VCF, there are crazy 32.
The Matrix VCF is an analog, multimode filter based on the legendary Oberheim Matrix-12. The 15 modes of the original have been taken over and extended by one more. Allan J Hall has added a full four-pole, all-pass phaser mode to it, making it even more versatile.
Besides this new one, you can find all your favorites, including low-pass, high-pass, band-pass, combinations of multiple types, and more. You can select them by hand with a dedicated knob and get instant feedback from the 16 LEDs that tell you exactly which filter you have selected.
It gets more fun with the option to animate the filter selection with CV. Patch an LFO into it and you get exciting filtering effects. Cutoff and resonance parameters give you full control over the filters.
A Filter Party
16 filter modes are already a ton of fun, but AJH didn’t stop there with its new Matrix VCF. It also hosts a new onboard P-Voice resonance distortion circuit, inspired by the famous Polivoks synths.
This spicy circuit alters how resonance behaves in each mode, introducing a richer character and ensuring self-oscillation in all filter modes. This expands the selection from 16 to a whopping 32 analog filter modes. This is called a filter selection.
On the I/O side, it features a 1V/oct input that tracks several octaves, an attenuated frequency control input, and both 1/3 and 2/3 scaled control inputs, perfect for keyboard filter tracking and more.
As a bonus, AJH has included an onboard VCA in the Matrix VCF. If you compare it with an oscillator and envelope, you have a compact without requiring an extra VCA module.
First Impression
There are few filter modules that still activate the GAS factor for me, since almost everything is available in Eurorack format these days. The Oberheim Matrix filter was still missing in the modular world, and it’s even pimped up with Polivok’s spice.
This looks and sounds like an excellent vintage filter. Just one downside: it’s only a mono filter; if it were stereo or dual, the GAS would be significantly higher for many. Maybe we will see one in the future.
AJH Synth Matrix VCF is available now for
More information here: AJH Synth
Available at my partners
Looks great!
There is also the Doepfer xpander filter that has the Matrix filter modes. I don’t know how close it is to the original but it’s a very fun filter with multiple outputs.
oh yes indeed. Doepfer has so many modules portfolio that you forget what they really have 🙂