2hp Logic (2010s)

Name: 2hp Logic
Brand: 2hp

A tiny gate logic module that turns simple pulses into rhythmic complexity with two operations: AND and OR.

Overview

The 2hp Logic hides in the cracks of a packed Eurorack case. Two jacks on the left, two on the right, and barely enough front panel for a name. It isn't a sound generator or a processor, and it isn't really a utility in the usual sense. It makes decisions. It listens to two gate or clock signals and answers one question: should this pulse pass? The answer depends on whether you use the AND channel or the OR channel, and that binary choice gives you a surprising amount of rhythmic depth.

The AND function only outputs a gate when both inputs receive a signal at the same time. Think of a bouncer at a club who wants both invites at once. That makes it good for syncopated hits that fire only when two separate rhythmic streams line up, like a snare that plays on the offbeat only if a hi-hat is also ticking, or a bass note that slips through only when two LFOs align. It also works for gating modulation sources, so an effect engages only when multiple conditions are met.

On the OR channel, the logic flips. Any pulse from either input gets passed through. It merges and combines, layering two clock sources into a denser pattern. If one sequencer pulses on quarter notes and another on eighth-note triplets, the OR output becomes a jittery, polyrhythmic stream. It earns its keep in drum patches: merging trigger sources, stacking percussion events, or feeding a noise VCA with multiple timing streams to make fills that evolve instead of repeating.

One detail in the design matters: the first channel is normalled to the second. If you only patch one input into the AND side, it also feeds the OR side. That assumes you'll want to run a single signal through both logic types, or chain them without extra cables. You can feed a master clock into AND, combine it with a delayed version of itself, then let the OR channel mix the original and the gated result. That gives echo-like rhythmic artifacts without any delay module at all.

Specifications

Manufacturer	2hp
Format	Eurorack
Width	2HP
Depth	45mm
Power Consumption	35 mA @ +12V, 3 mA @ -12V
Function	Dual-channel boolean gate operator
Logic Operations	AND, OR
Inputs	2 x Gate/Trigger (AND channel), 2 x Gate/Trigger (OR channel)
Outputs	1 x AND output, 1 x OR output
Normalization	AND channel input normalled to OR channel input
Signal Type	Digital gate/trigger (5V typical)
Module Type	Utility / Logic
Manual Available	Yes (PDF)
Production Era	2010s
Country of Origin	USA
Color Options	Silver, Black

Key Features

The AND Gate: Rhythmic Precision Through Exclusion

The AND channel doesn't generate events. It filters them. Two pulses must coincide for an output, so you can use it for ghost notes, conditional triggers, or rhythmic intersections that would be hard to program by hand. Patch a clock into one input and a delayed version of the same clock into the other, and you only get an output when both align, which makes a narrow time window for a trigger to pass. That's useful for tightening up slop in a sequence or for a "pulse within a pulse" effect. Some users feed envelope gates into the AND input so a sound plays only when a note is triggered and a modulation envelope is active.

The OR Gate: Rhythmic Expansion Through Inclusion

Where AND tightens, OR expands. It's the simplest form of signal summation for gates - any incoming pulse gets passed, regardless of source. That suits merging multiple sequencers, combining clock divisions, or layering percussion triggers. When two unrelated rhythms feed into OR, the output is a new rhythm altogether, full of off-kilter accents and syncopations. It's also a no-frills way to fan out a single trigger to multiple destinations without loading down the source. It lacks buffering, though, so long cable runs or high fan-out patches might need a dedicated mult downstream.

Minimalism as a Design Statement

Eurorack modules keep getting bigger, deeper, and more feature-laden. The 2hp Logic does two things, in 2HP. There are no switches, no attenuators, no CV inputs, no blinking LEDs. You don't patch it to tweak parameters, you patch it to make decisions. Its normalization encourages chaining with other 2hp modules like the Mixer, Attenuverter, or Delay, which can handle fairly complex tasks without eating up panel space.

Historical Context

The 2hp Logic emerged in the early 2010s, right as Eurorack was shifting from boutique curiosity to modular mainstream. Cases were filling up with oscillators, filters, and effects, but many builders were realizing they needed tools to organize, route, and manipulate signals. That's where utility modules like Logic found their niche. Other companies were building multi-function logic modules with XOR, NAND, and flip-flops. 2hp took the opposite approach: strip it down, make it tiny, and let patching do the rest.

It arrived alongside a wave of minimalist design in Eurorack - Think L-1, 4ms's Pod, or ALM's SQIJ. But 2hp stood out by committing fully to the 2HP form factor across its entire lineup. Every function, no matter how minor, got its own compact module. That appealed to skiff builders, minimalists, and anyone tired of wasting space on oversized panels. It also reflected a broader trend in modular synthesis: the idea that complexity arises from connection, not from individual modules.

Competitors like Intellijel and Doepfer offered more comprehensive logic modules with additional functions and buffered outputs, but those took up 4HP or more. The 2hp Logic wasn't trying to win on features. It was trying to win on density. For compact systems or small gaps in a case, it was often the only logic module that fit. It focused on the two most commonly used boolean operations, so it covered 80% of use cases in half the space.

Collectibility & Value

The 2hp Logic has never been rare or particularly valuable. It's a $94 module, and it stays that way, both new and on the used market. Collectors don't flip it for profit, and prices don't spike on eBay. That makes it accessible, but it also means 2hp has little incentive to reissue or revise it. If you see one, it's likely in working order, and if it isn't, the circuit is simple enough that most technicians can diagnose issues quickly.

Failures are uncommon, and when they happen they're usually power-related. The module draws 35mA from the +12V rail, which is modest, but in a heavily loaded system a reversed power cable or a noisy bus board can stress the onboard regulator. There are no moving parts, no pots to wear out, and no buffers to fail - just passive components and logic chips. That makes it one of the most reliable modules you can own, but there are no serviceable wear items. If the IC fails, it needs replacement. Documentation is available, and the design is open enough that DIY repairs are feasible.

When buying used, check for bent pins on the power connector and verify that both outputs respond to input signals. Some users report faint crosstalk between channels in high-gain patches, but this is usually due to cable quality or grounding issues rather than the module itself. Because it's so basic, there's little variation between units, with no "vintage" or "reissue" versions to track.