alm-busy-circuits/mfx

MFX

ALM Busy Circuits

The MFX is a compact 6HP Eurorack stereo digital audio multi effects processor. It offers 17 different full featured effects programs plus a number of metering utilities.282

Capabilities 1

Stereo Effects Processorstereo-effects-processor
17 effects programs plus utilities; 16-bit/44.1kHz stereo DSP processing.282

Jacks 8 — 6 in / 2 out

NameSignalVoltageDescription
Inputs (6)
CV1cv0V to 5V282
CV2cv0V to 5V282
CV3cv0V to 5V282
Clkclock282
Left Inaudio282
Right Inaudio282
Outputs (2)
Left Outaudio282
Right Outaudio282

Parameters 122

NameTypeRangeBehavior
Attack (TY-50 Dynamics)menu_settingIn compression mode: time for gain to be fully reduced after crossing threshold. In shaper mode: shortens or lessens attack transients.282
Bandwidthmenu_settingSets the sampling frequency of the delay line. Doubles delay time with each step down.282
Base Freqmenu_settingSets the frequency of the lowest bandpass filter. Shifts all bands together with respect to the Ratio setting.282
Bit Depth (2051 Bit Corrupter)menu_settingSets the bit depth of the dry signal.282
Bit Depth (Digi-PCM Echo)menu_settingSets the bit depth of the delay line.282
Brightnessmenu_settingChanges timbre of the spring sound.282
Buffer Sizemenu_setting1ms – 1000msSets the size of the buffer in ms when clock is internal. Ranges from 1-1000ms (Mono) and 1-500ms (Stereo and Dual modes).282
Burstmenu_settingEnables a burst of grains triggered by the Clk input.282
Clock (2051 Bit Corrupter)menu_settingSets if the buffer size is based on internal (INT) or external (EXT) clock.282
Clock (Digi-PCM Echo)menu_settingSets if the delay time is based on internal (INT) or external (EXT) clock.282
Clock (Tape-Tech Echo)menu_settingSets if the delay time is based on internal (INT) or external (EXT) clock.282
Clock Mult (2051 Bit Corrupter)menu_settingSets the buffer length as a multiple of the incoming clock pulse when clock is set to external.282
Clock Mult (Digi-PCM Echo)menu_settingSets the buffer length as a multiple of the incoming clock pulse when Clock is set to external.282
Clock Mult (Tape-Tech Echo)menu_settingSets the buffer length as a multiple of the incoming clock pulse when Clock is set to external.282
Cutoffmenu_setting20Hz – 20000HzSets the cutoff of the filter. Ranges from 20Hz to 20kHz.282
Damping (Almicon Reverb)menu_settingDarkens the reverb tail, both shortening its length and reducing high frequencies.282
Damping (Quaidra Reverb)menu_settingDarkens the reverb tail, both shortening its length and reducing high frequencies.282
Damping (Slinky Reverb)menu_settingSets the amount of feedback into the spring. Lower values equal longer, more resonant decays.282
Damping (Yetti Reverb)menu_settingDarkens the reverb tail, both shortening its length and reducing high frequencies.282
Densitymenu_settingSets the number of grains.282
Depth (Ensembles Ensemble)menu_settingSets the depth of modulation.282
Depth (Multi Phaser)menu_settingSets how pronounced the notches are (depth of the phasing effect).282
Diffusionmenu_settingReduces or increases the uniformity of the reverb tail, causing reflections to appear more distinct or thicker.282
Drive (TH-30 Distortion)menu_settingSets the amount of drive into the selected distortion type.282
Env Follow (Freq Shifter)menu_settingEnables envelope following to control the dynamics of the frequency shifted signal. Frequency Shifter mode only.282
Era (Almicon Reverb)menu_settingToggles the quality of the underlying reverb algorithm: '80s' uses lower bit depth with grainy sound and poor clipping resilience; 'NOW' has much higher resolution and improved saturation.282
Era (Quaidra Reverb)menu_settingToggles algorithm quality: '90s' uses lower bit depth with grainy sound and poor clipping resilience; 'NOW' has higher resolution and improved saturation.282
Fade Inmenu_settingApplies a smoothing envelope to the attack and decay of repeats in the buffer.282
FB Combmenu_settingSets the position of the comb filter effect caused by the feedback control.282
Feedback (Crumbular Echo)menu_settingSets the amount of feedback into the delay buffer.282
Feedback (Multi Phaser)menu_settingSets the amount of feedback, narrowing the shape of the notches as it is increased.282
Feedback (Tape-Tech Echo)menu_settingSets the amount of feedback into the delay buffer.282
Feedback (Ursa Minor Echoverb)menu_settingSets the amount of feedback into the delay buffer.282
Filter Modemenu_settingSelects the filter type: no filtering, low pass, high pass, or band pass.282
Flip Phasemenu_settingInverts the phase of the delay line.282
Freeze (Pocket PL8 Reverb)menu_settingWhen enabled, reverb tail decay is disabled and the reverb is frozen. A trigger at the Clk input will refreeze.282
High Cut (Crumbular Echo)menu_settingSets the cutoff frequency of a low-pass filter in the delay line.282
High Cut (Digi-PCM Echo)menu_settingSets the cutoff frequency of a low-pass filter in the delay line.282
High Cut (Freq Shifter)menu_settingSets the cutoff frequency of a low-pass filter on the wet signal. Frequency Shifter mode only.282
High Cut (Ursa Minor Echoverb)menu_settingSets the cutoff frequency of a low-pass filter in the delay line.282
High Cut (Yetti Reverb)menu_settingSets the cutoff frequency of a low-pass filter after the reverb tail.282
Length (Slinky Reverb)menu_settingSets the length of the spring and therefore the overall size of the reverb. High values reach more into echo territory.282
Lock Inmenu_settingLoops playback of the buffer, even if there is no audio in it.282
Loopmenu_settingLoops the currently stored delay buffer.282
Low Cut (Crumbular Echo)menu_settingSets the cutoff frequency of a high-pass filter in the delay line.282
Low Cut (Quaidra Reverb)menu_settingSets the cutoff frequency of a high-pass filter on the reverb tail.282
Low Cut (Ursa Minor Echoverb)menu_settingSets the cutoff frequency of a high-pass filter in the delay line.282
Low Cut (Yetti Reverb)menu_settingSets the cutoff frequency of a high-pass filter after the reverb tail.282
Make Up Gainmenu_settingSets the final output gain of the compressed or shaped signal.282
Max Frequencymenu_settingSets the maximum frequency that bands can reach before being reflected.282
Max Repeatsmenu_setting≤10Maximum number of repeats that may occur with every glitch, up to 10.282
Mixmenu_setting0% – 100%Sets the wet/dry blend. At 0% only the dry input is heard; at 100% only the wet effect signal is heard. Can be globally disabled and locked to 100% wet via the Utilities program.282
Mix Typemenu_settingPRE: applies Bit Depth and Sample Rate reduction pre-mix to both dry and wet signals. PST: applies reduction post-mix to wet signal only.282
Mod Clockmenu_settingSets if the modulation rate is based on internal (INT) or external (EXT) clock.282
Mod Depth (Digi-PCM Echo)menu_settingSets the depth of modulation over the delay time.282
Mod Rate (Digi-PCM Echo)menu_settingSets the rate of modulation over the delay time.282
Mod Rate (Ensembles Ensemble)menu_settingSets the modulation speed. Only visible if supported by the selected mode.282
Mod Rate (Modulating Panner)menu_setting0.05Hz – 8HzSets the rate of modulation in Hz when clock is set to internal. Ranges from 0.05-8Hz.282
Mod Rate (Multi Phaser)menu_settingSets the modulation rate of the phasing.282
Mode (2051 Bit Corrupter)menu_settingSets the I/O mode: Mono (mono in/out, max 1000ms buffer), Stereo (stereo in/out, same random seed, max 500ms), Dual (stereo in/out, different random seeds per side, max 500ms).282
Mode (Crumbular Echo)menu_settingSets the mode to either mono or stereo.282
Mode (Digi-PCM Echo)menu_settingSets the delay mode: Mono Delay (single delay line, mono out), Dual Tap (pair of lines mixed to mono), Stereo Tap (pair of lines hard-panned), Ping Pong (swap sides each repeat), Ext Feedback (single mono delay using only left in/out; right output is send, right input is return).282
Mode (Ensembles Ensemble)menu_settingSelects the chorus or ensemble mode: Juno I, Juno II + I, Alpha, RS I, RS II, Solina (mono), Wide, Vibrato.282
Mode (Modulating Panner)menu_settingSets the mode: Mono (pans left input between L and R outputs) or Scan (cross fades between left and right inputs to mono output).282
Mode (Multi Phaser)menu_settingSets the mode: Mono (mono in/out, up to 8 stages), Stereo (stereo in/out, up to 4 stages), Infinite Up (mono upward barber-pole, up to 4 stages), Infinite Down (mono downward barber-pole, up to 4 stages).282
Mode (Ring + Freq Modulator)menu_settingSets the mode to either ring modulation or frequency shifter.282
Mode (Squoval Rezonator)menu_settingSets the mode: Mono (mono in/out, up to 8 parallel filters) or Stereo (stereo in/out, up to 4 parallel filters per side).282
Mode (TY-50 Dynamics)menu_settingSets the dynamics processing mode: Stereo Compressor, Sidechain in R, Transient Shaper, or Stereo Expander.282
Mode (Ursa Minor Echoverb)menu_settingSelects between reverb or echo modes.282
Modulator (Ring Mod)menu_settingSelects between the internal modulation oscillator (INT) or external source (LxR). LxR mode expects carrier at left input and modulator at right, outputting in mono.282
Num Activemenu_setting1 – 8Sets the number of active bands: 1-8 (mono) or 1-4 (stereo).282
Osc Rate (Ring Mod)menu_setting20Hz – 11000HzSets the rate in Hz of the internal modulation oscillator. Ranges from 20Hz-11kHz.282
Output Gain (TH-30 Distortion)menu_settingReduces the final output of the distorted signal.282
Pitch Destinationmenu_settingRoutes the pitch shifter to either the delay's Feedback path or the Input signal.282
Pitch Shift (Ensembles Ensemble)menu_settingShifts the pitch of the incoming signal without affecting its time.282
Pitch Shift (Tape-Tech Echo)menu_settingShifts the pitch of the delay line without affecting the time.282
Pitch Shift (Yetti Reverb)menu_setting282
Play Headsmenu_settingSets the number of tape read heads for the echo density. The middle head is less stable than the outer ones.282
Pre-Delay (Almicon Reverb)menu_setting0ms – 99msDelays the onset of the reverb tail. Ranges from 0-99ms.282
Pre-Delay (Pocket PL8 Reverb)menu_setting0ms – 99msDelays the onset of the reverb tail. Ranges from 0-99ms.282
Pre-Delay (Yetti Reverb)menu_setting0ms – 100msDelays the onset of the reverb tail. Ranges from 0-100ms.282
Program (Ursa Minor Echoverb)menu_settingSelects one of 20 different time arrangements for the 8 delay taps (4 left, 4 right).282
Ratiomenu_settingSets the amount of gain reduction applied to the signal when it crosses the threshold. Compression mode only.282
Ratio (Squoval Rezonator)menu_settingSets the ratio between each filter's frequency in relation to the previous band.282
Recyclemenu_settingWhen enabled all grains are added to the feedback path for a more diffused sound; otherwise just a single tap is used for feedback.282
Reflectsmenu_settingEnables reflecting of any bands that cross the Max Frequency threshold.282
Regen (Digi-PCM Echo)menu_settingSets the amount of feedback into the delay buffer.282
Release (TY-50 Dynamics)menu_settingIn compression mode: time to return to original level after being reduced. In shaper mode: shortens or lessens release transients.282
Resonance (Modulating Panner)menu_settingSets the amount of filter resonance.282
Resonance (Squoval Rezonator)menu_settingSets the amount of resonance for all active bands.282
Reverse (2051 Bit Corrupter)menu_settingReverses playback of the buffer.282
Reverse (Digi-PCM Echo)menu_settingReverses playback of the delay buffer.282
Reverse (Pocket PL8 Reverb)menu_settingReverses the reverb tail.282
Sample Rate (2051 Bit Corrupter)menu_settingSets the sample rate of the dry signal.282
Shapemenu_settingSets the envelope shape of the grains.282
Shift (Freq Shifter)menu_setting0Hz – 1000HzChanges the frequency of the incoming signal in Hz. Ranges from 0Hz-1kHz. Frequency Shifter mode only.282
Size (Almicon Reverb)menu_settingSets the size/time of the reverb tail.282
Size (Pocket PL8 Reverb)menu_settingSets the size/time of the reverb tail.282
Size (Quaidra Reverb)menu_settingSets the size/time of the reverb tail.282
Size (Yetti Reverb)menu_settingSets the size/time of the reverb tail.282
Spraymenu_settingRandomly varies the size of the grains.282
Spread (Multi Phaser)menu_settingSets the width of the stereo image. Only applies to stereo mode.282
Stagesmenu_setting2 – 8Sets the number of notches ranging from 2-8 (mono) or 2-4 (stereo).282
Stereo (Pocket PL8 Reverb)menu_settingWidens the reverb to faux stereo via phase inversion. Includes settings for mild and full widening. When set to off, reverb is mono.282
Stereo (Squoval Rezonator)menu_settingShifts the frequency of the bands on right and left up and down respectively to create width. Only available in Stereo mode.282
Tap Level 1menu_settingSets the level of the first tap panned left and the first tap panned right.282
Tap Level 2menu_settingSets the level of the second tap panned left and the second tap panned right.282
Tap Level 3menu_settingSets the level of the third tap panned left and the third tap panned right.282
Tap Level 4menu_settingSets the level of the fourth tap panned left and the fourth tap panned right.282
Tap Multmenu_settingSets the time of the second tap as a multiple of the main time. Not used in Mono and Ext Feedback modes.282
Tape Agemenu_settingSets the age of the tape: increases noise, saturation, drop outs and darkness in the repeats.282
Thresholdmenu_settingSets the amplitude at which the compressor begins to take effect. Compression mode only.282
Tightnessmenu_settingSimulates a tighter physical plate dampening the reverb.282
Tilt Filter (TH-30 Distortion)menu_settingTilt-style EQ filter applied to the distorted signal, emphasising either high or low frequencies. Wide-ranging.282
Tilt Filter (TY-50 Dynamics)menu_settingTilt style EQ filter that sets the region of frequencies detected by the envelope followers. Transient Shaper mode only.282
Time (Crumbular Echo)menu_setting50ms – 999msSets the length of the delay buffer in ms. Ranges from 50-999ms.282
Time (Digi-PCM Echo)menu_setting0ms – 998msSets the length of the delay buffer in ms when Clock is set to internal. Ranges from 0-998ms x8.282
Time (Tape-Tech Echo)menu_setting0ms – 998msSets the length of the delay buffer in ms. Ranges from 0-998ms.282
Time (Ursa Minor Echoverb)menu_setting0ms – 254msSets the length of the delay buffer. Only applies to echo mode. Ranges from 0-254ms.282
Type (TH-30 Distortion)menu_settingSets the type of distortion. Options: Soft (analog-style soft clipping, rounds transients), Saturate (clipping with compressed harmonics), Overdrive (clipped signal introduces harsher harmonics), Digital (digital hard clipping, squares off transients), Wavefold (the digital wavefolder from the Tyso Daiko), Nuclear (maximum clipping — squares off all incoming transients), Warm (tube-style distortion).282
Wide (Slinky Reverb)menu_settingAdds a stereo widening effect to the reverb.282
Wow + Fluttermenu_settingIntroduces slight changes to the delay time, adding pitch warble and chorusing to the repeats.282

Firmware history 16 versions

VersionReleasedNotes
115Added Stereo Expander mode to TY-50 Dynamics; Mix control enabled for Transient Shaper and Sidechain In R modes; Added Fade In parameter to Bit Corrupter; Added FB Comb parameter to Multi Phaser.282
114Improved filter in Modulating Panner and resonators in Squoval Rezonator; fixed Digi-PCM clocking bug; more preset lockup fixes.282
113Fixed potential noise on some reverbs when bypassed; fixed Clock utility response; fixed potential lockups on some presets.282
112Skipped for Eurorack module; pedal only release.282
111Overhauled Crumbular engine; added Recycle and Shape parameters to Crumbular; added visualizations for Spray and Density; Ensemble Mod Rate made CV-able; added Wide mode to Slinky Reverb; added Warm distortion type to TH-30.282
110Added Preset Loader screen; merged Transient Shaper and Compressor into TY-50 Dynamics; added stereo Ensembles modes (Vibrato, Rotary, Alpha); improved Tape Echo tape aging and wow/flutter; improved Pre-Delay on Pocket PL8, Almicon and Yetti reverbs.282
109Fixed Axon UI slowdown bug.282
108Added Slinky spring reverb engine; added high-res modern Quaidra and Almicon reverb implementations; added shared global user presets (no longer limited to 2 per effect); spectrum analyser improvements.282
107Added spectrum analyser to Utilities; added Freeze, Reverse, and Tightness parameters to PL8 Reverb; fixed test tone, Bit Corrupter and Digi Delay initialisation bugs.282
106Added Squoval Resonator FX engine; added Infinite Up/Down modes to Multi Phaser; added Mix Type PRE/PST parameter to Bit Corrupter; added new static presets to most engines; fixed preset parameter loading bug.282
105All reverbs (except PL8) now perform wet/dry mix preserving stereo input; Crumbular stereo final mix fixed; improved clocking accuracy; fixed preset parameter loading; added Axon-2 support (tap tempo, toggle passthrough).282
104Introduced MFX VCV Rack version; fixed Bit Corrupter lockup with ext clock in stereo; fixed INT/EXT buffer update bug; improved Tape Delay external clocking stability; fixed Axon CV assignment save across power cycles; added Mumdance presets.282
103Added Yetti FDN Reverb and Multi Phaser engines; reworked Crumbular Echo with longer time and variance parameter; added state variable filter to Modulating Panner; added sidechain mode and stereo/dual modes to Bit Corrupter; added 440Hz test tone to Utilities; improved headroom for Quaidra and Almicon reverbs.282
102Added global wet/dry mix lock to Utilities (100% wet); added envelope follower toggle to Frequency Shifter; added clock metering to Utilities; fixed Frequency Shifter param names; summed L+R inputs on Ursa Minor; various bug fixes.282
101Fixed CV handling range; added pitch shifter destination toggle on Tape Delay; disabled CV on some reverb pre-delays to avoid lockup; fixed EXT/INT clock switching with CV; fixed Almicon pre-delay; summed L+R inputs on Crumbular, Tape Delay and reverbs. (Odd versions considered beta releases.)282
100Initial release firmware.282

References 2

  1. [282]
    ALM-032 'MFX' Manual v0.9 (firmware v115)manual
    verified 2026-05-06
  2. [283]
    ALM MFX product pageproduct_page
    verified 2026-05-06