alm-busy-circuits/mco

MCO (mkII)

ALM Busy Circuits

Compact digital multi-voice synthesiser and VCO in 6HP, offering eight synthesis voice programs (wavetable, additive, JP-style digi-synth, vocoder, virtual-analog, bass/drum, SID chip, and vocal formant), each with assignable CV modulation, up to four-voice chords, built-in envelopes and LFOs, and dual audio outputs.1177

Capabilities 6

Additive Synthesisadditive-synthesis
1177
Chord Generatorchord-generator
Global chord parameter available across all voice programs; supports up to 4-voice chords with CV-controllable chord type and inversion.1177
Envelope Generatorenvelope-generator
Internal ADSR and AD envelopes triggered by the Trig In jack; applied to the internal VCA and available as an assignable modulation source.1177
LFOlfo
1177
Vocodervocoder
1177
Wavetable Oscillatorwavetable-oscillator
Realized via the DigiWave voice program, which morphs between two wavetable waveforms with five mix modes and a sub oscillator output.1177

Jacks 8 (6 in / 2 out)

NameSignalVoltageDescription
Inputs (6)
CV1cv0V to 5V1177
CV2cv0V to 5V1177
CV3cv0V to 5V1177
Ext Inmixed—Audio-rate input whose function varies by voice program — used for FM, hard sync, ring modulation, or audio input processing such as vocoding depending on the active voice.1177
Assignable destinations
Hard Sync1177 FM1177 Vocoder modulator1177 Ring modulation1177 V/Oct for internal mod oscillator1177
Trig Inmixed—Normally functions as a gate or trigger to drive the internal ADSR or AD envelope and VCA; can be repurposed as a direct CV input for VCA level or as a general assignable CV input.1177
V/Octcv—1177
Outputs (2)
Out Aaudio—1177
Out Baudio—Secondary output; in DigiWave carries the sub oscillator (one octave down) with selectable shape; in other voices provides stereo widening or alternative output depending on the active voice program.1177
Assignable destinations
Sub oscillator1177 Stereo1177

Parameters 65

NameTypeRangeBehavior
ABMixknob—1177
BDetuneknob—1177
Biasknob—1177
Chordmenu_setting—Selects from an array of standard 12-tone chord shapes and 4 unison detune options for up to 4-voice chord generation; can be CV-controlled with defined voltage boundaries per chord type.1177
Chorusknob—1177
Clickknob—Sets the starting frequency of the pitch envelope as a multiple of the base frequency, producing an increasingly sharp click transient. Only visible when Trig/Gate is active.1177
Complex/Harmonicsknob—1177
Crushknob—1177
CrushMixknob—1177
Cutoff (BC8000)knob—1177
Cutoff (Virtana)knob—1177
Detuneknob—1177
Disttypemenu_setting—1177
Driftknob—1177
Driveknob—1177
Ext Mode (DigiWave)menu_setting—1177
Ext. Mixknob—1177
ExtMode (AEIOU)menu_setting—1177
Fauxpassknob—1177
Filter (BC8000)menu_setting—1177
Filter (DigiWave)menu_setting—1177
Filter (SIDGuts)menu_setting—1177
Flipknob—1177
FMDepthknob—1177
FMRatioknob—1177
Formantknob—1177
Gruffnessknob—1177
Invert Bmenu_setting—1177
LFO Modemenu_setting—Sets each of the three internal LFOs to Free Running, Retrig (restarts on trigger and cycles indefinitely), or One-Shot (restarts on trigger and plays once). Reset requires Trig In Parameter set to Trig or Gate.1177
Mix (A/B)knob—1177
MixModemenu_setting—Selects from five algorithms used to morph or combine Wave A and Wave B: Morph, Splice, Multiply, Min, and Max.1177
Mod Sourcemenu_setting—1177
Mod Typemenu_setting—1177
ModDepthknob—1177
Mode (Sylon)menu_setting—1177
ModRateknob—1177
ModSelectmenu_setting—Controls how modulation assignment sources are accessed: Simple mode shows them when scrolling past the lowest parameter value and via back-button+knob combo; Button mode hides them from parameter browsing, requiring the back-button+knob combo exclusively.1177
Notch/Freqknob—1177
Oscillator Shapemenu_setting—1177
OscMixknob—1177
Pitchmenu_setting0octave – 7octaveSets the base frequency of the voice across stacked pages for Octave, Semitone, and Cents, with an additional Scale parameter for the built-in quantizer. Frequency spans approximately 8 octaves from C0 to B7.1177
Pre-Gainknob—1177
PWMknob—Replaces the last percentage of the output waveform cycle with silence to produce a pulse-width modulation effect; available across all wave shapes.1177
PWM (SIDGuts)knob—1177
PWM (Virtana)knob—1177
Qualityknob—1177
Ratiosmenu_setting—1177
Rez (BC8000)knob—1177
Rez (Virtana)knob—1177
Shape (SIDGuts)menu_setting—1177
Slewknob—1177
Spreadknob—1177
Subknob—1177
SubLenknob—1177
Tablemenu_setting—Selects between the Factory wavetable bank and user-uploaded wavetable banks; user tables are split into four groups of 16 waves, divided so the first half feeds Wave A and the second half feeds Wave B.1177
Thumpknob—1177
Trig In Parametermenu_setting—Configures how the Trig In jack is used: as a gate for internal ADSR, a trigger for internal AD envelope, a direct CV input for external VCA level, or a general assignable CV input. In CV mode the internal VCA is disabled.1177
Vibratoknob—1177
VoxAmenu_setting—1177
VoxBmenu_setting—1177
VoxToneknob—1177
Wave Aknob—Selects the primary wave shape from the active wavetable bank.1177
Wave Bknob—Selects the secondary wave shape combined with Wave A according to the active Mix Mode.1177
Waveformmenu_setting—Selects one of four oscillator waveforms inspired by JP8000/JP8080 shapes — Supersaw, Triangle Mod, Noise, and Feedback — each with two dedicated sub-controls.1177
Whisperknob—1177

Firmware history 7 versions

VersionReleasedNotes
106—Multi-mode filter added to DigiWave; Preset manager in Settings can now be modulated to load User presets with CV; '+Random' preset option added to each voice's preset list; setting added for changing AXON-2 A/B button functions.1177
105—New AEIOU vocal formant synthesis voice added; stereo mode added to DigiWave Out B options; modulation now smoothed for continuous controls.1177
104—Chord list updated to match Cizzle for compatibility with NOH Modular's Pianist module; added Diminished, Minor 9, and Major 9 chords; removed Major 4.1177
103—Quantizer added to Pitch stack with standard Pam scales plus 3 user scales; One-shot LFO mode added; Trapezoid, Exponential, and Logarithmic LFO shapes added; Chorus effect added to Virtana voice; Offset and Attenuation pages now display parameter values; Octaves and Fifths swapped in Chord list to match Cizzle.1177
102—DigiWave now resyncs when triggered; resync-capable voices only resync if envelope is closed; fixed Sylon hanging on preset load.1177
101—Boot graphic updated; level control now saves correctly across power cycles; envelope curves made smoother.1177
100—Initial release firmware.1177

References 2

  1. [1177]
    ALM046 'MCO (mkII)' Operation Manualmanual
    ● verified 2026-06-09
  2. [1178]
    ALM MCO (mkII) product pageproduct_page
    ⚠ verified 2026-06-09 · manufacturer changed since last verified