2hp Sine (2019–)

Name: 2hp Sine
Brand: 2hp

A sine wave so clean it sounds like silence coming to life.

Overview

Turn the knob on the 2hp Sine and you hear a pure tone rise. There's no wobble, no drift, no analog patina. This isn't a vintage-style oscillator chasing warmth. It's a digital oscillator that cuts through a mix with surgical precision. Even so, it's musical. It's a minimalist module in both form and function, and it fits in a 2HP footprint. You tune it by ear, and the flawless sine wave works as a foundation, a modulator, or a drone that never tires.

Most 2HP modules give up functionality to save space. The Sine packs in a full-featured VCO with two distinct outputs, internal wavefolding, and sub-oscillator flexibility, and it keeps rock-solid 1V/oct tracking. The primary output delivers a harmonically pure sine wave across a wide frequency range, from sub-bass rumbles to piercing highs, with no audible stepping or glitches. You can patch it into a filter and forget about it until you realize it's been carrying your entire patch for an hour.

The sub output offers a blendable mix of a sine tone one octave below or a fifth above the main frequency. That gives it harmonic depth without needing additional modules. Both outputs feed into an internal wavefolder, which can be engaged to add rich, evolving overtones and turn that pristine sine into something gritty, metallic, or even bell-like. You can keep the Sine pure for FM sources or sub-bass, or push it into harmonic complexity when you need texture. It's like having two oscillators in one, only they're the same waveform wearing different masks.

Specifications

Manufacturer	2hp
Production Years	2019–
Original Price	$149
Width	2HP
Depth	45mm
Power	+12V: 80mA, -12V: 4mA
Outputs	Primary Sine, Sub Sine (octave down/fifth up blendable)
Wavefolding	Internal, on both outputs
Frequency Control	1V/Oct input, manual tuning knob
CV Inputs	Frequency (1V/Oct), FM (attenuated)
Waveform	Digital sine wave (harmonically pure)
Sub Oscillator Function	Switchable blend: octave below or fifth above
Tracking Accuracy	Pristine 1V/oct, digitally stable
Color Options	Black, Silver
Weight	Approx. 50g

Key Features

Digital Purity, Analog Flexibility

The 2hp Sine uses digital architecture to generate its waveform, which means no thermal drift, no tuning instability, and no need for constant calibration. Analog VCOs need warm-up time or occasional tweaking. The Sine locks in and stays there, which suits live sets or patches that demand consistency. It doesn't feel sterile, though. The wavefolding circuit adds some grit, especially when driven with external signals or modulated via CV. It's not a distortion stage in the traditional sense. It folds the waveform back on itself and creates harmonics that evolve in real time. Patch an LFO into the FM input, engage the wavefolder, and you get a shimmering, evolving pad that sounds like light refracting through glass.

Sub Output as Harmonic Engine

The sub output is also a compositional tool. By blending between an octave below and a fifth above, you can create harmonic intervals without patching a second oscillator. This helps in small systems where every HP counts. For a perfect fifth drone, set the sub to fifth-above and mix it in. For a deep sub-bass foundation, switch to octave-down and let it anchor your patch. Both tones are derived from the same core oscillator, so they track perfectly, with no tuning drift and no phase issues. It lets you imply chords or motion in a monophonic setup without extra modules.

Wavefolding as Sonic Sculptor

Most wavefolders are separate modules, often taking up 4HP or more. 2hp baked one into a 2HP oscillator, which is borderline absurd. The wavefolding isn't just an on/off feature. It responds dynamically to input level and modulation, allowing for everything from gentle warmth to aggressive metallic tones. When used as an FM source, the folded sine can generate complex sidebands that analog oscillators struggle to match. Users report particularly striking results when modulating filters or other digital oscillators with the Sine's folded output. It cuts through with a clarity that analog FM often lacks.

Historical Context

The 2hp Sine arrived in 2019, when Eurorack was deep into the "skiff era," a push toward ultra-compact, efficient modules that could fit into lunchbox-sized cases. Other manufacturers were expanding into multi-function modules or complex sequencers. 2hp doubled down on minimalism, with single-purpose tools that did one thing exceptionally well. The Sine was part of a four-module rollout that year, including the Bell (a physical modeling voice), Grain (a granular processor), and DC (a DC offset generator).

At the time, digital oscillators like Mutable Instruments' Plaits dominated the high-end market, offering a wide range of waveforms and synthesis models. The Sine took a different niche: purity instead of versatility. It appealed to minimalists, skiff builders, and anyone tired of tuning drift in their analog VCOs. It also reflected a broader trend in modular synthesis, which was the acceptance of digital as a legitimate sonic alternative and not only a cost-saving measure.

Collectibility & Value

The 2hp Sine remains in production and widely available, so it's not a "collector's item" in the traditional sense. Its reputation has grown steadily, though, and used units rarely dip below $100, even in fair condition. Mint examples with original packaging can fetch $130 - $140. The original price was $149, which holds up well against inflation and the rising cost of Eurorack gear.

Failures are rare, but not nonexistent. The main concern is the tiny trim pots on the back of the module - five in total, used for calibrating pitch tracking and sine wave symmetry. These are delicate and not user-serviceable without a steady hand and a fine-tipped screwdriver. Over-tweaking can throw off tracking or cause waveform asymmetry, though documentation shows that 2hp provides clear instructions for calibration. The power draw is minimal (+12V: 80mA, -12V: 4mA), so it's safe for even the most power-constrained skiff systems.

When buying used, check for bent pins and make sure the knob turns smoothly. Some early units had slightly sticky pots, though this was never a widespread issue. Also verify that the wavefolding behaves as expected: at full engagement, it should add harmonics without introducing digital artifacts or clipping. The module is digitally generated, so there's no aging of components to worry about - no capacitors to dry out, no transistors to fail.