2HP Filt (2016–)
A sliver of analog magic that spills out four flavors of filter color from a space no wider than your thumbnail.
Overview
You’re not supposed to fit a full multimode analog filter into 2HP. It defies physics, common sense, and every Eurorack convention about what a filter should look like. But 2HP did it anyway—quietly, efficiently, and with a kind of elegant minimalism that makes you wonder why everyone else is still using 8HP for the same job. The Filt doesn’t just compress functionality; it distills it. You plug in a signal, tweak cutoff and resonance, and suddenly you’ve got a full spectrum of tonal shaping at your fingertips—low pass, high pass, band pass, and notch, all simultaneously available. It’s not flashy, it doesn’t have a screen or touch controls, and it won’t patch itself for you. But what it lacks in spectacle, it makes up for in sheer utility and sonic character.
There’s a quiet confidence in how the Filt behaves. It doesn’t scream for attention like some self-oscillating monsters that distort the moment you turn the resonance past noon. Instead, it stays clean, precise, and musical—right up until you want it to misbehave. Push it, and it’ll deliver that sweet, resonant squelch perfect for acid lines or dubby filter sweeps. Back it off, and it turns into a silky smoothing agent, rounding off harsh waveforms with the subtlety of a well-aged ribbon filter. It’s not modeled after any classic topology you can name—no 12dB Moog ladder, no 24dB Oberheim SEM clone—but it doesn’t need to be. It’s its own thing: compact, neutral enough to work anywhere, yet characterful when you ask it to be.
What really sets the Filt apart is how it forces you to think differently about module real estate. In a format where every HP counts, having a full multimode filter in just 2HP feels like cheating. It’s the kind of module you install and forget—until you realize you’re using it on nearly every patch. It’s not the centerpiece of your system, but it’s the glue. Need to split a drone into its spectral components? Filt’s got you. Want to extract rhythmic pulses from noise via band-pass resonance? Done. Need a notch to carve out a frequency hole in a feedback loop? There it is. It’s the Swiss Army knife of filtering, but without the flimsy knife and useless toothpick.
Specifications
| Manufacturer | 2HP |
| Production Years | 2016– |
| Original Price | $99 |
| Width | 2HP |
| Depth | 50 mm |
| Power Consumption | 40mA +12V, 39mA -12V |
| Filter Types | Low Pass, High Pass, Band Pass, Notch (simultaneous outputs) |
| Control Voltage Inputs | Cutoff Frequency CV, Resonance CV |
| Manual Controls | Cutoff Frequency knob, Resonance knob |
| Audio Inputs | 1 x Audio In |
| Audio Outputs | 1 x Low Pass, 1 x High Pass, 1 x Band Pass, 1 x Notch |
| CV Inputs | 1 x Cutoff CV, 1 x Resonance CV (normalized to attenuated front panel control) |
| Filter Slope | 12 dB/octave (2-pole) |
| Topology | Analog multimode state-variable filter |
| Self Oscillation | No |
| Color Options | Silver, Black |
| Mounting | Eurorack 3U |
| Weight | Approx. 40g |
Key Features
Four Filters in One, All at Once
Most multimode filters make you choose: low pass today, high pass tomorrow. The Filt laughs at that limitation. All four filter types—low pass, high pass, band pass, and notch—are available at once, each with its own dedicated output. This isn’t just convenient; it’s transformative. You can route the same source through all four paths and blend them dynamically, creating complex, evolving textures that would take three or four modules to achieve otherwise. Want to send the low-passed fundamental to your main mix, use the band-pass resonance as a percussive trigger, and feed the notch output into a reverb for spectral gaps? You can. The Filt doesn’t gatekeep—its outputs are always live, always ready.
Minimal Footprint, Maximum Utility
At 2HP wide and 50mm deep, the Filt is skiff-friendly and case-saving in a way few filters can claim. It’s the kind of module you install in “dead zones”—those awkward 2HP gaps between larger modules that usually end up housing blank panels or utility attenuators. But here, it’s doing serious sonic work. Its compactness isn’t a gimmick; it’s a philosophy. 2HP built this knowing that space is the most valuable currency in Eurorack, and they spent it wisely. The front panel is clean: two knobs, four outputs, two CV inputs, and an input. No extras, no fluff. Everything you need, nothing you don’t.
Smooth, Musical Response with Voltage Control
The filter’s 12 dB/oct slope gives it a gentler character than steeper 24 dB designs, making it ideal for subtle tonal shaping rather than drastic timbral surgery. The cutoff knob has a logarithmic taper that feels natural under your fingers, and the resonance control adds warmth without getting fizzy or unstable. CV over cutoff lets you sweep the filter dynamically—great for envelope following or LFO modulation—while the resonance CV input allows for expressive, voltage-controlled intensity. Since the CV inputs are normalized to the front panel controls, you can use the knob as an attenuator when patching in modulation, giving you hands-on control over modulation depth without needing a separate attenuator.
Historical Context
The 2HP Filt arrived in 2016, right as Eurorack was shifting from boutique curiosity to mainstream adoption. Modular wasn’t just for academics and experimental composers anymore—it was being used by pop producers, electronic musicians, and bedroom tinkerers. Space in cases was at a premium, and manufacturers began exploring ultra-compact designs. 2HP, founded by former Doepfer engineer Robin Whittle, had already built a reputation for doing the impossible in minimal space—2HP VCA, 2HP LFO, 2HP ADSR. The Filt was the next logical step: proving that even complex analog circuits could be shrunk without sacrificing functionality.
At the time, most multimode filters occupied 6HP or more. Mutable Instruments’ Steiner-Parker filter (via Braids or later standalone modules) was a favorite, but it took 8HP. MakeNoise’s STO was powerful but even larger. The Filt didn’t try to compete on features or raw character—it competed on efficiency. It wasn’t the first 2HP module, but it was one of the first to make you question why anything else took up more space. It wasn’t a clone, a homage, or a recreation. It was a new kind of utility: dense, quiet, and indispensable.
The Filt also reflected a broader trend toward “skiff culture”—the rise of tiny, portable, ultra-dense cases for on-the-go synthesis. In that world, every millimeter counts, and the Filt became a cornerstone. It wasn’t the flashiest module, but it was the one you couldn’t afford to leave behind.
Collectibility & Value
The 2HP Filt isn’t a rare bird, but it’s not generic either. It’s widely available, still in production, and priced at a very accessible $99. Used units typically sell for $70–$90 depending on condition and color preference (black panels sometimes fetch a slight premium). There’s no collector’s markup, no scalping, no waiting lists—just a well-made, reliable module that does its job and stays out of the way.
Failures are rare. The module has no moving parts beyond the potentiometers, and the circuit is simple enough that there’s little to go wrong. The most common issue reported is intermittent audio from the jacks, usually due to dust or oxidation—easily fixed with contact cleaner. The power draw is modest (40mA/+12V, 39mA/-12V), so it won’t tax even the smallest power supplies. There are no known design flaws, no batch issues, and no need for modifications. If you buy one, it’ll work as intended for years.
When buying used, check that all four outputs are functioning and that the CV inputs respond smoothly. Some users have reported slight detents in the knobs, but this is usually just mechanical resistance from the bushings and doesn’t affect performance. The module is available in silver or black front panels—purely aesthetic, but some builders prefer one over the other for visual coherence.
Its collectibility isn’t based on scarcity, but on utility. You don’t collect the Filt because it’s rare; you keep it because you use it. It’s the module that disappears into your setup until you realize you’d have to replace it with three others to get the same functionality. That kind of quiet indispensability is its own kind of value.
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