ALM Pip Filter (2025–)

A deceptively simple 4HP filter that punches way above its size, hiding a pingable resonant core and built-in VCA behind a minimalist face.

Overview

Slap a signal into the ALM Pip Filter and you’ll immediately notice two things: how much warmth it adds despite its tiny footprint, and how quickly it starts singing when you crank the resonance. This isn’t some sterile digital model—it’s an analog two-pole low-pass with a distinctly organic tilt, the kind that breathes with your patch instead of just processing it. At only 4HP, it’s skiff-friendly and unobtrusive, but don’t mistake its size for limitation. It’s got a trigger input that lets you “ping” the filter for plucked, resonant blips that feel like they were pulled from a vintage string machine, and a built-in VCA that’s normalled open so you can shape amplitude without eating extra space. It’s the kind of module that seems modest at first glance but becomes essential after a week of patching.

The cutoff knob feels smooth and precise, and the dual CV inputs—one with an attenuverter, the other with rough V/Oct tracking—give you real flexibility in how you modulate the filter. You can blend external sources like LFOs or envelopes, then tweak their influence on the fly. The resonance control is where things get juicy: turn it up and the filter starts to howl, self-oscillating into a sine-like tone that’s not perfectly stable but has character—raw, slightly gritty, and full of analog charm. It won’t replace a dedicated VCO, but as a bonus oscillator when you’re tight on space? It’s a sneaky-good option. And because it’s designed to be pinged, it excels in rhythmic patches—think marimba hits, FM-like attacks, or percussive stabs that bloom and decay with natural resonance.

It’s not a 24dB Moog-style monster, nor is it trying to be. The 12dB/oct slope is gentle by design, letting harmonics through in a way that keeps sounds musical rather than surgical. That makes it ideal for warming up digital oscillators, softening harsh waveforms, or adding movement to drones without sucking the life out of them. The built-in VCA is a thoughtful touch—many compact filters make you add a separate VCA to gate the output, but here it’s baked in and ready to go. You can leave it normalled and use the filter’s trigger input to shape both timbre and amplitude, or patch into the VCA input for independent control. It’s these kinds of design decisions that make the Pip Filter feel like it was built by someone who actually uses modular gear, not just spec sheets.

Specifications

Key Features

Compact Dual-Pole Filter with Attenuverting CV Control

The heart of the Pip Filter is its 12dB/oct low-pass design, which delivers a warm, musical roll-off that’s especially effective on bright or digital sources. Unlike steeper filters that can feel aggressive when resonance is high, this one stays musical even at the edge of oscillation. The dual CV inputs are a standout: one is normalled and features an attenuverter, letting you invert and scale modulation from an envelope or LFO directly on the module. The second CV input offers rough V/Oct tracking, which means you can use it to play the filter melodically when paired with a keyboard or sequencer—though it’s not precision-tuned, so it’s better for tonal sweeps than exact pitch intervals. This dual-input setup gives you real patching versatility without cluttering the panel.

“Pingable” Trigger Input for Percussive Articulation

One of the most expressive features is the trigger input that allows you to “ping” the filter. Send a short gate or trigger, and the filter responds with a resonant pluck—perfect for emulating string machines, marimbas, or synthetic percussion. The behavior is highly responsive to resonance level: low resonance gives a soft bump, while high resonance produces a sustained, singing tone that decays naturally. This makes it a powerful tool in rhythmic patches, especially when paired with a clock divider or random trigger source. It’s not just a filter—it’s a sound generator in its own right when used creatively.

Built-In VCA with Normalled Open Path

In a format where every HP counts, integrating a VCA into a filter module is a smart move, and ALM executes it well. The VCA is normalled open, meaning the signal passes through even if you don’t patch into the VCA input—so you can use the filter standalone or add amplitude control when needed. Patch a gate or envelope into the VCA input, and you gain independent control over the output level, letting you shape the envelope of the filtered sound. This eliminates the need for a separate VCA in simple patches, freeing up space for other modules. It’s especially useful in skiff builds or minimalist systems where efficiency is key.

Historical Context

The Pip Filter arrived in 2025 as part of ALM’s new “Pip” series—compact, no-frills modules designed for maximum utility in minimal space. At a time when Eurorack systems are increasingly constrained by case size and power, the Pip series speaks directly to builders who value efficiency without sacrificing analog character. The Pip Filter doesn’t reinvent the wheel, but it distills decades of filter design into a form that’s accessible, affordable, and deeply usable. It sits in a lineage of compact filters from makers like Intellijel and Make Noise, but with a distinctly British pragmatism—no flashy extras, just solid circuitry and thoughtful integration.

Its closest relatives aren’t flagship filters with multiple modes or digital brains, but workhorse modules like the Mutable Instruments Steiner-Parker or the Doepfer MS-20 clone—simple, resonant, and expressive. What sets the Pip Filter apart is its integration of the VCA and pinging capability in such a small footprint. In an era where “utility” modules are increasingly valued, this one blurs the line between filter and voice element. It also reflects a broader trend toward “skiff-friendly” designs—modules that cater to portable, travel-ready systems without compromising sonic quality. Made in England and backed by a two-year warranty, it’s a statement of confidence in build quality at a time when many boutique modules are outsourced overseas.

Collectibility & Value

As of 2026, the Pip Filter is still in production and readily available new for around $145 USD or £110 GBP. It hasn’t yet entered the vintage market, so used prices remain close to retail—typically $100–$130 depending on condition. Given its recent release, it’s not a collector’s item yet, but it’s already gaining a reputation as a “must-have” utility filter in compact builds. There are no widespread reports of reliability issues, and the reverse power protection adds peace of mind for beginners. The build quality is solid: clean PCB assembly, sturdy jacks, and a well-finished front panel.

That said, potential buyers should be aware of its limitations. The resonance’s rough V/Oct tracking means it won’t stay in tune across a wide keyboard range—fine for effects and accents, but not for melodic playing. Some users on modular forums have noted that the self-oscillation can be slightly unstable at extreme settings, producing a wobble that’s musical in context but not suitable for precise tuning. These aren’t flaws, per se, but characteristics of its analog design. If you’re looking for a surgical, stable filter, this isn’t it. But if you want something with grit, responsiveness, and a bit of soul, the Pip Filter delivers.

For those building a skiff or travel case, this module is a no-brainer. It’s also an excellent entry-point filter for newcomers who want to explore resonance, pinging, and basic CV modulation without committing to a larger, more complex module. Keep an eye out for used units from reputable sellers—given its simple circuit, there’s little that can go wrong, but always check for bent pins or damaged jacks before buying. No major failure modes have been documented, and the power draw is low enough to avoid stressing even modest power supplies.

eBay Listings

ALM Busy Circuits Pip Filter Compact Filter EURORACK - B-STK

$125

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