2HP Tune (2010–Present)

A tiny quantizer that snaps chaotic voltage to a musical scale with a twist of a knob, in a package smaller than a matchbox.

Overview

Picture a patch with cables everywhere and CV wobbling from an LFO that modulates a noise source through a slew limiter. Nothing in it sounds like music. The 2HP Tune fixes that. It doesn't make sound. It doesn't oscillate, filter or delay. It takes any incoming pitch CV, wobbly, random or just out of key, and locks it to one of 11 built-in musical scales, including chromatic, whole tone and octatonic. That keeps a modular jam from sliding into atonal chaos. It isn't flashy, but in a Eurorack system it does a job you need done.

The Tune is notable for how little space it takes. It is exactly 2HP wide, the narrowest standard module size, so you could fit three of them in the width of a standard laptop charger. In that sliver sits a full quantizer with a knob and a single-button scale selector. No menus, no OLED screens, no firmware updates. Voltage goes in and corrected voltage comes out. The front panel is nearly bare: a knob labeled "Bias," a push-button switch to scroll through scales, and a single LED that blinks when it's quantizing.

Then there's the Bias control. Most quantizers snap your CV to the nearest note in a scale. The Tune also lets you shift the whole scale up or down in semitone steps, so you can transpose a melody on the fly without touching your sequencer. Want to move from C major to D Dorian mid-phrase? Twist the knob. Bias also lets you play every mode of a given scale without reprogramming a single step. In a live set, that knob changes a melody in real time, a bit like a jazz musician reharmonizing a chord progression.

The Tune isn't for everyone. It has no MIDI input, no user-defined scales and no microtonal tuning tables. If you work in alternate tunings or want Balinese gamelan scales, this isn't your tool. It's built for immediacy, not flexibility. Its 11 preset scales cover most Western harmonic ground - major, minor, pentatonic, blues, whole tone, diminished and octatonic - but they won't satisfy a microtonal explorer. For the 90% of Eurorack users who just want random voltage bursts to sound like actual music, it's the fastest and cleanest route.

Specifications

Manufacturer	2HP
Production Years	2010–Present
Original Price	$109
Type	Synth Module
Power Supply	Eurorack ±12V
Max Power Consumption	40 mA (+12V), 3 mA (-12V)
Depth	45mm
Width	2HP
Inputs	1 x CV Input (Pitch)
Outputs	1 x Quantized CV Output
Controls	Bias Knob, Scale Select Button
Indicators	1 x LED (Quantize Activity)
Scales	11 Preset Scales (Chromatic, Major, Minor, Pentatonic, Whole Tone, Octatonic, etc.)
Color	Silver or Black Panel
MIDI	No
Effects	None
Keyboard Size	N/A
Weight	Approx. 50g

Key Features

The Bias Knob: Modal Magic in Real Time

Bias is what moves the Tune from utility toward instrument. Most quantizers are static and map incoming CV to a fixed scale. The Tune lets you move that scale. Turn the knob and the whole quantization grid shifts up or down in semitone increments. You can start in C major, bias up two semitones to hear the same sequence in E Phrygian, or up seven to land in G Lydian. That goes beyond simple transposition and gives you modal exploration on the fly. In performance, a plain sequencer pattern becomes a shifting harmonic landscape. The knob has a smooth, precise feel with no jitter and no stepping, so subtle or dramatic changes are easy to make.

Scale Selection: Less Choice, More Focus

With only 11 preset scales and nothing user-programmable, the Tune makes you work within limits. You get no scale libraries and no MIDI dumps, just a short set of useful options. There's chromatic (for when you want no quantization at all), major and minor (the backbone of tonal music), pentatonic (for blues and rock), whole tone (for dreamy, ambiguous harmonies) and octatonic (for jazz and tension). The lack of customization is a design choice. The Tune assumes you'd rather make music than spend 20 minutes programming a scale. The single push-button cycles through scales in a fixed order, and the LED flashes to indicate selection. That isn't the fastest way to jump to a specific scale, but it invites you to try a melody in diminished instead of Dorian, and happy accidents follow.

Minimalism as a Virtue

The Tune is 2HP wide and 45mm deep. It draws minimal current (40mA on +12V, just 3mA on -12V), so it won't tax your power supply even in densely packed cases. The build is solid: aluminum panel, precision potentiometer, no wobble or flex. In a format where modules compete with flashing lights and colorful graphics, it's the quiet one. It's available in both silver and black panel versions. For travelers or small-case builders, it's a quantizer that doesn't take space from oscillators or filters.

Historical Context

When the 2HP Tune launched around 2010, Eurorack was still a niche within a niche. Doepfer's A-100 system had been around since the ’90s, but modular was far from mainstream. Most quantizers were wide, complex modules, such as Intellijel's Quadrax or Make Noise's Pressure Points, and they gave deep functionality at the cost of panel space. The Tune arrived as a counterpoint: a single-purpose module in the smallest footprint possible. It fit a growing trend in Eurorack toward small, focused utility modules that solved specific problems.

At the time, 2HP (founded by Tony Rolando, formerly of Doepfer USA) had already built a reputation for minimalist, high-quality designs. The Tune wasn't their first module, but it became one of their best known, partly because it met a common need. Modular users were patching more generative, chaotic systems (random sequencers, chaotic oscillators, sample-and-hold circuits), and they wanted a compact quantizer. It wasn't the first quantizer, but it was the first to make quantization accessible in both price and physical size. Intellijel and Mutable Instruments eventually released their own compact quantizers, but the Tune stayed a benchmark for simplicity.

It also arrived just before the Eurorack boom of the 2010s, when boutique manufacturers flooded the market with feature-heavy, screen-laden modules. The Tune went the other way. It had no USB, no MIDI, no firmware updates and no display. It just worked, reliably, for over a decade.

Collectibility & Value

The 2HP Tune isn't rare. Production has been steady since 2010. It isn't cheap used either. New units still sell for $109 direct from 2HP, and the used market follows that. Expect to pay $80 - $100 in good condition, depending on color and seller. Silver panels are slightly more common, while black panels, especially early runs, can fetch a small premium among collectors who want their cases to match. Unlike some boutique modules, the Tune has no major failure points. There are no moving parts beyond the knob and button, and the circuit is simple enough that repairs are straightforward. Service technicians observe that the most common issue is bent pins on the power connector, usually from careless insertion into a crowded bus board. Otherwise, the module is nearly bulletproof.

There are a few things to check before buying used. First, test the Bias knob for smooth operation, with no jumps or dead zones. Second, verify that the scale selector cycles through all 11 scales and that the LED blinks with each change. Some users report occasional firmware glitches in very early units (pre-2012), where the module might skip a scale or lock up, but a simple power cycle usually clears it. A full reset, done by holding the button while powering up, can reinitialize the scale counter if needed. There are no known capacitor aging issues or corrosion problems, thanks to the low power draw and minimal internal components.

For new users, the Tune remains a smart buy. It’s not flashy, but it’s one of those modules you didn’t know you needed until you patch it in and suddenly your random voltage sequences sound like melodies. For experienced builders, it’s a space-saving essential—perfect for filling that awkward 2HP gap next to a power connector. And for minimalists, it’s a philosophy in module form: do one thing, do it well, take up as little space as possible. It won’t appreciate like a vintage Roland, but it also won’t disappoint.