ALM MCO (2024–)

A 6HP Eurorack module built around the digital sound of the ’90s and 2000s. It has seven synth engines, chords, effects, and a full voice architecture.

Overview

Plug in the ALM MCO and turn the encoder, and it steps through a set of digital synth sounds from that era. The bright OLED display shows what each engine is doing. The module goes past imitating vintage digital synths. This is not the original MCO, a compact wavetable oscillator that earned cult status. The new MCO (officially the MkII, though it's just "MCO" now) is a full synth voice in 6HP. It sits between an oscillator, a voice module, and a desktop synth.

Each of the seven synthesis engines behaves like a standalone instrument, with envelopes, LFOs, chord generation, and dual outputs. The lineup is a JP-8000-style supersaw, a 12-operator additive engine, a SID chip emulation, a vocoder that doubles as a tone generator, a virtual analog engine, a bass specialist that can drop very low kicks, and a wavetable core that accepts custom user tables via USB-C. Every one of those engines supports up to four-voice chords. That means pads or stacked leads from a single module, with no external polyphony management.

The MCO doesn't pretend to be analog. It has a clear, precise digital sound, closer to a high-end 1998 workstation than a gritty lo-fi emulator. The aliasing is there, sometimes aggressively. That hard digital edge gives the BC8000 engine its supersaw bite and the DigiWave its crystalline, FM-like sheen. Anyone after smooth, buttery waveforms should look elsewhere. The MCO works in digital artifacts, clock noise, and bit-crunched textures, the sound of synths that were trying to be "futuristic" and ended up sounding of their time.

Specifications

Manufacturer	ALM Busy Circuits
Production Years	2024–
Original Price	$289 USD
HP	6
Depth	32mm
Power Consumption	+12V: 70mA, –12V: 30mA
Synthesis Types	Wavetable (DigiWave), Additive (ToneSum), Virtual Analog (Virtana), Supersaw (BC8000), Vocoder (Sylon), Bass Synth (Oomph), SID Chip Emulation
Polyphony	Up to 4 voices per engine (chord mode)
Outputs	Dual audio outputs (Out A, Out B)
Inputs	V/Oct, Audio Rate Input, Trigger, 4 assignable CV inputs (expandable to 8 via Axon)
Display	High-resolution color OLED
Control Interface	Single encoder with push-button, menu-driven UI
Preset System	Factory and user presets per engine, power-cycle memory
Modulation	Built-in LFOs, envelopes, audio-rate FM and sync
Connectivity	USB-C for firmware updates, wavetable upload, backup/restore
Expander Support	Axon-1 and Axon-2 for additional CV control
Software Version	Available as VCV Rack module
Weight	Not specified
Dimensions	6HP x 32mm depth
Country of Origin	England

Key Features

The Seven Engines: More Than Just Modes

The engines are full synthesis architectures, each with its own modulation options. The DigiWave engine carries on from the original MCO as a multidimensional wavetable oscillator, with user-uploaded wavetables via USB-C drag-and-drop. You can import classic 90s ROMpler tables or design your own in Audacity and drop them in like MP3s in 2003. The ToneSum engine is a 12-operator additive design that covers bell-like tones and complex, evolving textures, and it feels closer to a Korg OASYS than a Eurorack module. BC8000 handles the JP-8000 supersaw with detune, width, and unison controls.

Virtana is a virtual analog engine with pitch drift, soft sync, and a filter-like character even before external processing. Sylon is a full vocoder with carrier and modulator paths, and it can also generate tones independently, which is rare for a module this size. Oomph is for drum patches. It generates sub-bass, kicks, and percussive thumps, with envelope shaping that rivals dedicated drum modules. The SID engine is a full emulation of the 6581/8580 chip, with filter character, ring modulation, and noise, bringing the C64's gritty sound into the modular world.

Chords, CV, and the Axon Expansion

The chord implementation is where the MCO departs most from traditional oscillators. Every engine supports up to four-voice chords, with preset inversions and four user-defined chords. It goes beyond stacking octaves. You can trigger minor 9ths, diminished clusters, or custom voicings from a single trigger. With the built-in envelopes and LFOs, the MCO works as a complete voice without external modulation sources. For more CV control, there are four assignable inputs, plus support for Axon-1 and Axon-2 expanders. The Axon-2 alone doubles the CV inputs to eight, so pitch, timbre, chord type, and effect parameters can all be modulated in real time. That is a lot of control for 6HP.

USB-C and Firmware Evolution

USB-C does more than firmware updates. You can back up the entire module state, restore presets, or upload custom wavetables without leaving your DAW. The firmware has changed quickly since launch. Updates added a multi-mode filter for DigiWave, stereo output options, new LFO shapes (trapezoid, exponential, logarithmic), and a formant-based AEIOU voice. The preset manager now supports CV control for loading user presets, so the sound source can change over time on its own. ALM is still developing the module well after release.

Historical Context

The MCO arrives while Eurorack is reconsidering its analog bias. For years, digital modules were seen as niche, either lo-fi curiosities or sterile emulations. With more powerful processors and better DACs, digital synthesis in modular has improved. The MCO is a direct response to the nostalgia for 90s and 2000s digital synths: the Roland JP-8000, Korg Z1, Yamaha SY series, and Ensoniq TS-10. Those machines were dismissed in their time as "cold" or "clinical," and revered decades later for their sonic fingerprints.

ALM didn't build the MCO to compete with Mutable Instruments' Plaits or Noise Engineering's Ciat-Lonbarde line. Its approach is different. It favors complexity, menu diving, and deep parameter control over immediacy. It's also a spiritual sibling to ALM's own Pamela's PRO Workout, with the same UI language and workflow. Plaits offers quick, performative access to a variety of engines. The MCO asks you to dive in and tweak. It's not a "set and forget" module.

Collectibility & Value

As a 2024 release, the MCO is too new to have a vintage collectibility status. At $289 new, it's priced competitively against other digital modules like the Mutable Instruments Clouds (discontinued) or the Squarp Pyramid. Used units are already trading within 10-15% of retail, which points to strong demand and low attrition. Build quality is excellent, with reverse power protection, solid PCB construction, and a sturdy front panel. Failures are rare, though the OLED display and encoder could be long-term wear points.

For buyers, the main risk is workflow more than reliability. The MCO demands engagement. If you hate menu diving or want instant gratification, this isn't your module. Watch for firmware version 106 or later, which includes the multi-mode filter and CV-controllable preset loading. Units with original packaging and proof of firmware updates hold slightly more value, especially as custom wavetable libraries grow in the community. The VCV Rack version at $20 is a low-risk way to test the concept before buying hardware.