by Brandon Ivers
Vermona is a German company that has been around since at least the late 60s, and they’ve made everything from organs and luxurious spring reverbs to high-quality analog synthesizers and drum machines over the years. More recently, Vermona got into making Eurorack modules, and they brought over a lot of the quality and aesthetics from their lineage of hardware. One of the more comprehensive [and particularly wild] of these modules is the twinVCFilter.
Prior to trying out the twinVCFilter, I was expecting it to sound like the filter in Vermona’s PERfourMER synthesizer, which has a sort of ladder/Moog-ish sound with a smooth and vintage response. I blame part of that preconception on appearance: the twinVCFilter has a similar look as the PERfourMER, with big white knobs and relatively roomy spacing between everything [especially for Eurorack]. However, the twinVCFilter can be quite nasty and acidic, not to mention way more flexible, particularly when used with the Extension module.
The twinVCFilter can go from relatively smooth 12db territory to a raspy, self-oscillating scream largely due to the interplay between gain and resonance. Take, for instance, OTA-based filters as seen on synths like the MS-20 or SH-101: the more you crank resonance, the less you can drive the input of the filter if you still want the resonant overtones to pop out. This is not entirely the case with the twinVCFilter, which can still be overdriven with the gain knob AND turned into a bizarre squelchy mess. And because the twinVCFilter is a multimode, dual filter design, the module’s gain staging allows you to stack the filters in series for even more unpredictable distortion and resonance effects.
The Extension module opens up a ton of possibilities with the twinVCFilter, and for me, this is where things get really interesting. Without the extension, each filter can do the typical multimode high-pass, low-pass, and band-pass filtering, but the extension adds notch filtering, additional filter polarizers, and the ability to output all filter types at once. Combine this with a mixer module, and you can get very creative by layering different filter responses with each other.
For example, I love creating multiband effects by splitting drums through one of the filters’ high and low-pass outputs simultaneously and sweeping each band with the polarizers via CV or the knobs. Each band can then be treated with other processing, summed to mono, and run back into the other filter for another round. This is also a fun approach when creating feedback patches, as you have a lot of wiggle room in between each filter’s gain, resonance, and the type of filter you are mixing back in on itself.
Depending on how much room you have in your rack, the size of the twinVCFilter and the Extension can be a pro or a con. At a combined 34 HP, these two modules have a significant footprint. When you consider how many routing options and how much flexibility is on display—not to mention the spacious panel layout—the HP are justified.
The amount of filters available in Eurorack these days is a bit overwhelming, but the twinVCFilter has a uniquely thick, detailed sound and the ability to go from “general purpose” to wild and weird without a problem. While I don’t think the Extension module is required to make good use of the twinVCFilter, it lends a flexibility to the module that helps it carve out a niche for more layered and esoteric filter-based patches. If you’re already a fan of Vermona, this module is a no-brainer. And if you don’t know about Vermona, this filter is a great place to start.
24 HP 75mA +12V 55mA -12V
10HP 30mA +12V 20mA -12V