ALM Busy Pip Slope mk II ()
A tiny but devious 4HP envelope generator that morphs, loops, and surprises—like a pocket-sized composer for your modular rack.
Overview
Don’t let the size fool you: the ALM Busy Circuits Pip Slope (mk II) is a dense little brain for shaping motion in a Eurorack system. At just 4HP wide, it’s the kind of module you slap into an empty skiff slot without hesitation, only to find it becoming the centerpiece of half your patches. It’s officially billed as a compact envelope and function generator, but in practice, it’s more of a shape-shifting modulation engine—capable of behaving like a traditional envelope, a looping LFO, or something altogether more unpredictable. Owners report using it for everything from percussive plucks to evolving drone textures, thanks to its ability to morph between exponential, linear, and logarithmic envelope shapes on the fly. It’s not flashy, but it’s deeply flexible—the kind of module that rewards poking around with CV sources and feedback loops.
Built in the UK by ALM Busy Circuits, the Pip Slope mk II carries the no-nonsense design ethos the brand is known for: minimal front panel real estate, maximum functionality under the hood. It’s skiff-friendly, reverse polarity protected, and designed to survive the chaos of a densely packed system. While it doesn’t scream for attention, it earns its place through reliability and clever architecture. It supports both Attack/Decay and Attack/Sustain/Decay envelope types, with direct knobs and voltage control over both stages—so you can tweak manually or let your system take the wheel. Whether you’re using it as a traditional envelope or letting it loop into oblivion, it’s one of those modules that feels more like a collaborator than a tool.
Specifications
| Manufacturer | ALM Busy Circuits |
| Model Number | ALM028 |
| Dimensions | 4 HP, 38 mm deep |
| Current Draw | 30 mA +12V, 10 mA -12V, 0 mA 5V |
| Envelope Times | ranging approx 1ms to 7 minutes per stage |
| Maximum Envelope Level Output | Selectable 5v or 8v |
| Reverse Polarity Protection | Yes |
| Skiff Friendly | Yes |
Key Features
Morphing Envelope Shapes
One of the standout tricks up the Pip Slope mk II’s sleeve is its ability to morph between exponential, linear, and logarithmic envelope slopes. This isn’t just a switch between presets—it’s a continuously variable control, letting you slide from snappy, punchy attacks to slow, swelling curves with a twist of a knob. That kind of flexibility is rare in such a compact module, and it opens up a wide range of tonal possibilities, from acoustic emulations to abstract modulation sweeps.
Looping with Character
While many envelope generators can loop, the Pip Slope mk II offers three distinct loop modes: regular loop, decreasing amplitude, and decreasing time. That means you can create rhythmic sequences that fade out like a dying drum machine, or ones that speed up into a frenzy before collapsing. These aren’t just gimmicks—they’re compositional tools that encourage experimentation. Pair it with a filter or VCA, and you’ve got an entire evolving phrase in a single module.
Flexible Triggering and Outputs
The module accepts both trigger and gate inputs, making it compatible with a wide range of timing sources across different modular ecosystems. It also features an ‘End of Cycle’ trigger output, which fires when the envelope completes a cycle—useful for chaining multiple envelopes or syncing other events in your patch. This extra output, added in the mk II revision, is a small but meaningful upgrade over earlier versions.
Voltage Control and Dual Envelope Modes
With both direct knob control and CV inputs for Attack and Decay times, the Pip Slope mk II integrates smoothly into complex patches. You can modulate the envelope timing from other LFOs, sequencers, or even audio-rate signals for FM-like effects. The ability to switch between AD and ASD envelope types adds further utility, letting it handle both percussive and sustained sounds without needing additional modules.
Output Level Switching
A toggle switch lets users select between 5V and 8V maximum envelope output levels. This is particularly useful when interfacing with different modules that expect varying CV ranges—some vintage-style oscillators or filters respond better to higher control voltages, and having that option onboard eliminates the need for external attenuverters.
Historical Context
The Pip Slope mk II is an updated version of the original Pip Slope, retaining the same 4HP footprint while adding several key enhancements. According to manufacturer documentation, the mk II includes increased output resolution, finer control over fast envelopes, a new morphing shape control, additional loop modes, and the aforementioned End of Cycle trigger output. The switchable 5V/8V output level was also introduced in this revision, making it more adaptable to different system standards. These improvements were made without increasing the module’s size or power draw, a testament to the efficient design philosophy of ALM Busy Circuits. The Mk II version is explicitly noted as adding "new features not found on the original," positioning it as a functional upgrade rather than a complete redesign.
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