ALM Busy Circuits Pip Slope Mk II (2018–)

Name: ALM Busy Circuits Pip Slope Mk II
Brand: ALM Busy

A 4HP nuclear warhead of modulation—tiny, precise, and capable of detonating entire sequences with a single trigger.

Overview

You can count the number of Eurorack modules that genuinely redefined what "compact utility" means on one hand, and the Pip Slope Mk II is welded to your index finger. It doesn’t announce itself with flashing lights or a 20-page manual—just four knobs, a few jacks, and a deceptively quiet front panel that belies the surgical-grade envelope generator lurking behind it. This isn’t just another AD/ASR module you slap in a skiff to save space. It’s a full-function modulation engine that can morph from a snappy percussion shaper to a glacial, looping LFO with the flip of a switch and a twist of a knob. And it does it all in 4HP, which still feels like cheating.

At its core, the Pip Slope Mk II is a dual-mode envelope generator: Attack/Decay for percussive hits, Attack/Sustain/Release when you need that classic synth envelope contour. But calling it “just” an envelope generator undersells it. It’s equally at home as a function generator, a looping LFO, a burst modulator, or a rhythmic trigger sequencer. The magic starts with the shape control—smoothly morphing the envelope slope from logarithmic (sharp attack, long tail) to linear (predictable rise/fall) to exponential (slow start, fast snap). This isn’t a coarse switch; it’s a continuous, voltage-controllable parameter, letting you sculpt the character of an envelope in real time. Pair that with voltage control over both attack and decay times, and you’re not just shaping sound—you’re choreographing it.

Where the Mk II pulls ahead of the original is in refinement. It retains the same svelte 4HP footprint but adds critical upgrades: selectable 5V or 8V maximum envelope output (handy for driving VCAs or modulating other modules that prefer higher CV), increased output resolution for smoother curves, and finer control over fast envelope times—no more mushy sub-millisecond attacks. The “End of Cycle” trigger output is a quiet hero, spitting out a precise pulse when the envelope completes, whether it’s a one-shot or a loop. That’s gold for cascading sequences, triggering fills, or clocking other modulators in sync. And yes, it loops—three modes, in fact. Regular loop for steady LFO action, decreasing amplitude for echo-style decays, and decreasing time for that “bouncing ball” effect where each repetition gets quicker until it fizzles out. It’s the kind of detail that makes you wonder how you ever lived without it.

Specifications

Manufacturer	ALM Busy Circuits
Model	Pip Slope Mk II
Model Number	ALM028
Production Years	2018–
Module Type	Envelope Generator / Function Generator
HP Size	4
Depth	38mm
Power Supply	+12V, -12V
+12V Current Draw	30mA
-12V Current Draw	10mA
Envelope Modes	Attack/Decay (AD), Attack/Sustain/Release (ASR)
Envelope Time Range	Approx. 1ms to 7 minutes per stage
Shape Control	Morphs between logarithmic, linear, and exponential slopes
Voltage Control	Attack and Decay times (CV inputs with attenuators)
Trigger Inputs	Gate input (for ASR), Trigger input (for AD)
Outputs	Envelope output, End of Cycle trigger output
Max Envelope Level	Selectable 5V or 8V
Loop Modes	Regular loop, decreasing amplitude, decreasing time
Reverse Polarity Protection	Yes
Country of Origin	United Kingdom

Key Features

Shape Morphing: The Secret Weapon

The shape control isn’t just a tone knob for envelopes—it’s a timbral architect. Most envelope generators lock you into a fixed curve: exponential for punch, linear for neutrality. The Pip Slope Mk II lets you slide between them continuously. Want a pluck that starts soft but snaps shut like a mousetrap? Dial in logarithmic attack and exponential decay. Need a swell that crests slowly and fades into nothing? Linear all the way. And because the shape can be voltage-controlled (via the front panel knob’s CV input), you can modulate the envelope’s character over time—say, using an LFO to make a filter sweep evolve from smooth to snappy across a sequence. This kind of dynamic contouring is rare in modules this size, and it’s where the Pip Slope transcends utility to become an expressive tool.

Looping Intelligence

Most envelope generators either loop or they don’t. The Pip Slope Mk II doesn’t just loop—it thinks about how it loops. The three loop modes aren’t gimmicks; they’re compositional tools. The regular loop turns it into a precision LFO with complex shapes, great for modulating pitch or pan in evolving patterns. The decreasing amplitude mode mimics natural decay—perfect for emulating reverb tails or hand-drum rolls. The decreasing time mode is the standout: each cycle gets faster, creating a rhythmic acceleration that feels organic, like a ball bouncing to a stop. Use it to drive a sequencer’s clock divider, and you’ve got a fill that builds tension and collapses in on itself. It’s the kind of behavior that feels more algorithmic than analog, yet it’s all generated in real time with no firmware tricks.

End of Cycle Trigger: The Silent Conductor

That little “End of Cycle” trigger output is the Pip Slope’s backstage pass to the rest of your rack. Every time the envelope finishes—whether it’s a one-shot or the last loop in a sequence—it fires a clean, 5V trigger. This isn’t just for resetting other envelopes (though it’s great for that). It’s a compositional signal. Patch it to a noise source and a VCA, and you’ve got a burst generator. Send it to a sample & hold, and you’ve got a stepped random voltage on every envelope completion. Use it to clock a second Pip Slope, and you’ve built a dual-stage modulator with interlocking rhythms. It turns the module from a passive source into an active participant in your patch, creating feedback loops and cascading events that feel alive.

Historical Context

The Pip Slope Mk II arrived in 2018, a time when Eurorack was bloating. Modules were getting bigger, more colorful, more feature-laden—often at the cost of utility and elegance. In that climate, the Pip Slope stood out like a haiku in a world of doorstop novels. It wasn’t trying to be a Swiss Army knife with 17 blades; it was a scalpel. While Make Noise’s Function and Intellijel’s Dual ADSR dominated the “premium envelope” space with multiple stages and complex looping, ALM Busy Circuits went the opposite direction: minimal footprint, maximum flexibility. The original Pip Slope had already earned cult status, but the Mk II refined it into something sharper. It competed not with the feature monsters, but with the idea that small modules had to be simple. It proved that density didn’t have to mean compromise—that you could pack advanced modulation into 4HP without sacrificing control or character.

It also arrived as the DIY and skiff-friendly movement gained steam. Eurorack wasn’t just for wall-sized cabinets anymore; people were building lunchbox systems, travel rigs, desktop setups. The Pip Slope Mk II, with its reverse polarity protection, compact depth, and skiff-friendly design, was tailor-made for that shift. It wasn’t just a module—it was a philosophy: do more with less, elegantly.

Collectibility & Value

The Pip Slope Mk II isn’t rare—ALM has kept it in steady production since 2018—but it’s highly sought after, and for good reason. New units sell for around £110 GBP (roughly $140 USD), and the used market reflects that value. Expect to pay $100–$130 depending on condition, with mint units from reputable sellers holding firm at the higher end. It’s not a speculative collector’s item like a vintage Roland synth, but it’s a “forever module”—one that people buy and keep. The build quality is excellent: PCB-mounted jacks, sturdy knobs, clean silkscreen. Failures are rare, but there’s one known issue worth mentioning. Some early Mk II units exhibit high-frequency parasitic oscillation on the output—a 1MHz ripple visible on oscilloscopes, reported by multiple owners. It doesn’t usually affect audio or CV performance in practice, but it’s a quirk to be aware of. If you’re buying used, ask if the unit has been tested with a scope, or plan to check it yourself.

Maintenance is minimal. No moving parts, no trimpots to drift. The only real wear point is the toggle switch for the 5V/8V output level—mechanical switches can eventually fail, but there are no widespread reports of this. Because it’s a digital-analog hybrid (the timing and logic are microcontroller-driven), firmware updates are possible, and ALM has released patches in the past to refine behavior. Always check the official site for the latest firmware if buying used. Overall, it’s a low-risk purchase—no recap needed, no aging electrolytics to worry about. What you see is what you get: a clean, reliable, and brutally effective module.