2hp Grain (2019–)

Name: 2hp Grain
Brand: 2hp

The tiniest granular maelstrom you can patch—small enough to hide, wild enough to lose yourself in.

Overview

You’ll blink and miss it on a rack: two slender HP, matte silver or black panel, one knob for density, another for wet/dry mix, a third for pitch shift. No display, no menu diving, no patch memory. The 2hp Grain doesn’t announce itself like a flagship module—it whispers, then detonates. Plug in any audio source, turn up density, and the signal fractures into a shimmering cloud of micro-grains, each a sliver of the original, smeared across time and frequency like ink in water. It’s not subtle. At high density, it’s less “granular synthesis” and more “sonic vaporization,” dissolving guitars, vocals, or drum loops into evolving textures that hover between melody and noise. And yet, for all its destructive potential, it remains startlingly musical—especially when you dial in just enough wet signal to let the ghost of the original peek through.

Positioned as 2hp’s first foray into effects processing, the Grain landed in late 2019 with a reputation already bubbling in the modular community. The brand had built its name on minimalist utility modules—attenuators, multiples, logic—that maximized function in minimal space. Grain flipped that script: same footprint, but now it was doing the work of a full digital effects unit. At $149 MSRP, it undercut nearly every granular processor on the market, especially Mutable Instruments’ Clouds (discontinued in 2020), which it was inevitably compared to. But calling Grain a “Clouds alternative” misses the point. It doesn’t do reverb, it doesn’t do spectral processing, it doesn’t buffer three seconds of audio. What it does—granular freezing, pitch shifting, and texture generation—it does with surgical focus and almost alarming efficiency.

Owners report that the module excels in motion: pair it with an LFO on density, and the grain cloud pulses like a beating heart; modulate pitch with a random voltage, and it stutters into glitchy melodies. It’s not a “set and forget” effect. It wants to be poked, prodded, destabilized. The lack of a freeze button—frequently cited as a missing feature—turns out to be less of a limitation than it first appears. Instead of locking a buffer, you shape the texture in real time, treating the input signal as a living source rather than a captured sample. This makes it ideal for processing live inputs or oscillators that are themselves evolving. But it also means Grain won’t replace a looper or sample player. It’s a processor, not a recorder. And that distinction matters.

Specifications

Manufacturer	2hp
Production Years	2019–
Original Price	$149
Width	2HP
Depth	42mm (skiff-friendly)
Power	+12V: 78mA
Power	-12V: 9mA
Power	+5V: 0mA
Inputs	Audio In, CV for Density, CV for Mix, CV for Pitch (V/Oct)
Outputs	Audio Out
Processing Type	Digital granular synthesis
Grain Parameters	Density, pitch shift, wet/dry mix
CV Control	All parameters voltage-controllable
Sample Rate	48kHz (inferred from typical Eurorack digital modules)
Bit Depth	24-bit (inferred)
Weight	Approx. 40g (module only)
Mounting	Standard Eurorack 3U
Color Options	Silver, black
Manual	Available online via 2hp website

Key Features

Granular Engine in a Sliver of Space

The core of the Grain is its real-time granular processor, which continuously slices incoming audio into micro-fragments—grains—typically ranging from 1ms to 100ms in duration. The density knob controls how frequently these grains are triggered; at low settings, you hear distinct repeats or echoes, almost like a slapback delay. As density increases, the grains blur into a continuous texture, forming clouds that retain the timbral DNA of the source but lose its temporal structure. Unlike some granular modules that allow grain size or position to be modulated independently, Grain keeps it simple: density is the primary sculpting tool. This limitation forces creativity—instead of tweaking multiple grain parameters, you learn to ride the threshold between order and chaos, where rhythmic pulses dissolve into amorphous fog.

Full CV Control Over Texture and Pitch

Every front-panel parameter has a corresponding CV input with attenuverters, making Grain deeply patchable. The pitch shift CV accepts V/Oct, so it can track melodic sequences when paired with a sequencer or keyboard. This allows for harmonically locked granular textures—imagine a vocal phrase transposed up an octave while being atomized into a shimmering halo. The mix CV lets you automate the balance between dry and wet signal, enabling dramatic swells or rhythmic gating effects. And density modulation is where Grain truly sings: patch in an LFO, a random voltage, or an envelope follower, and the texture breathes, stutters, or explodes on cue. Service technicians observe that the CV inputs are well-calibrated and noise-free, a testament to 2hp’s attention to analog-digital interfacing.

No Buffer Freeze—And That’s the Point

One of the most debated omissions is the lack of a freeze or hold function. Unlike Clouds or other granular modules, Grain does not allow you to capture and sustain a static buffer. Once the input signal stops, the grain cloud collapses. Some users initially see this as a flaw, but collectors note it reinforces Grain’s role as a live processor rather than a sample manipulator. It encourages dynamic patching, where the source and effect evolve together. That said, if you need sustained granular pads independent of input, you’ll need to pair Grain with a loop recorder or use it post-oscillator. The trade-off is worth it for many: no freeze means no memory management, no loading screens, no latency. It’s always ready, always responsive.

Historical Context

The 2hp Grain arrived at a turning point in Eurorack. By 2019, the format had exploded in popularity, and digital modules—once rare and expensive—were becoming more accessible. Mutable Instruments had set the bar with Clouds, a multi-effects module that included granular processing, but it was 16HP wide and priced at $399. Smaller players like Qu-Bit and Spectral Sound were exploring digital textures, but few had attempted granular synthesis in such a compact form. 2hp, known for its no-frills, high-efficiency modules, saw an opening: what if you could distill granular processing down to its essence and fit it in two HP? The result was Grain—a module that didn’t try to do everything, but did one thing with ruthless efficiency.

It also reflected a broader shift toward “minimalist digital” in modular synthesis. Rather than packing in features, designers began focusing on immediacy and playability. Grain fit perfectly: no menus, no firmware updates (as of research data), no hidden functions. What you see is what you get. Competitors like ALM’s Befaco Loquelic Iteritas or Intellijel’s Rainmaker offered more granular control, but at much higher cost and size. Grain wasn’t trying to win a spec sheet battle—it was trying to be the module you’d always have patched, the one you’d reach for when you wanted to turn a simple oscillator into a storm of sound.

Collectibility & Value

As of 2026, the 2hp Grain remains in production and widely available, which keeps prices stable. New units sell for $220–$260, reflecting inflation and shipping costs since its $149 MSRP. Used units in working condition typically go for $150–$190, depending on finish and seller location. There’s no significant markup for collectibility—this isn’t a limited-run grail. But it’s also not a module that depreciates. Its utility ensures steady demand, especially among skiff builders and minimalists who value its footprint.

Failures are rare, but service technicians observe a few potential issues. The most common is damaged power connectors from improper insertion, given the module’s shallow depth and tight fit in some cases. The PCB is compact, so rough handling during installation can stress solder joints. There are no user-serviceable parts—no fuses, no batteries, no moving components—so if it works out of the box, it’s likely to keep working. No widespread firmware bugs or recalls have been documented. When buying used, check for bent pins and test all CV inputs, as the small jacks can wear over time. A unit that powers up and responds to modulation is almost certainly healthy.

For those restoring or building a vintage-modern hybrid rack, Grain is a safe addition. It doesn’t require recalibration, doesn’t drift, and won’t color the signal when bypassed (though it has no hard bypass switch). Its digital nature means it doesn’t age like analog circuits—no capacitor rot, no op-amp degradation. The only wear is cosmetic: scuffs on the panel or faded labeling, which 2hp does not offer replacements for. Overall, it’s one of the lowest-maintenance modules in a rack, which only adds to its appeal.