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Waldorf Iridium Desktop

Waldorf Music GmbH — User Manual Rev. 3, September 2023 (OS version 3.x)
Software: Rolf Wöhrmann | Hardware: Oliver Rockstedt, Frank Schneider, Rolf Wöhrmann | Design: Axel Hartmann

Table of Contents

  1. Overview & Key Specifications
  2. Desktop vs. Keyboard — Key Differences
  3. Rear Panel Connections
  4. Basic Operation
  5. Sound Layers & Display
  6. Oscillator Section
    1. Wavetable Oscillator
    2. Waveform Oscillator
    3. Particle Generator (Granular)
    4. Resonator
    5. Kernel Synthesis
    6. Oscillator Mixer (OSC MIX)
  7. Dual Filter Section
  8. Digital Former Section
  9. Envelopes Section
  10. LFO Section
  11. Effects (5 Slots)
  12. Modulation Matrix & Komplex Modulator
  13. Master Mode
  14. Perform Mode
  15. Global Mode
  16. Loading & Editing Samples
  17. Appendix — Synthesis Basics, FAQ, Modulation Sources/Destinations, Specs

1. Overview & Key Specifications

The Waldorf Iridium Desktop is a high-class desktop synthesizer offering a remarkable range of synthesis methods within a single instrument. It is fully digital with analogue-inspired architecture, made in Germany.

SpecificationIridium Desktop
Polyphony16 voices (shared across both layers)
Sound Layers2 independent layers (Layer 1 / Layer 2) — can be Layered or Split
Oscillators per Voice3 oscillators, each independently selectable synthesis type
Synthesis TypesWavetable, Waveform (analog models), Particle Generator (granular/sample), Resonator, Kernel
FiltersDual analog-modeled filters per voice (independent routing options)
Digital FormerAdditional digital filter/FX processor in signal chain
Envelopes6 envelopes: Amp, Filter 1, Filter 2, Free 1, Free 2, Free 3
LFOs6 LFOs per voice
Effects5 effect slots (Chorus, Flanger, Delay, Reverb, and more)
ModulationModulation Matrix + Komplex Modulator
DisplayTouchscreen display
Pads16 pads (Notes, Scale, Chords, Trigger modes)
Audio I/OStereo out (2× TS mono jack), Stereo in (2× mono jack), Headphones (¼" TRS)
MIDIDIN MIDI In / Out / Thru, USB MIDI (Computer + Controller ports)
CV/GateCV/Gate/Clock In and Out (Eurorack compatible)
StorageMicroSD card slot (FAT/FAT32), USB 2.0 ports
OSUpdateable firmware (Rev. 3.x, July 2023 at time of manual)
ManufacturerWaldorf Music GmbH, Remagen, Germany

💡 This manual covers both the Iridium Desktop and Iridium Keyboard. Desktop-specific features are highlighted throughout with a blue bar.

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2. Desktop vs. Keyboard — Key Differences

🖥️ Desktop-specific
FeatureDesktopKeyboard
KeysNone — requires external MIDI keyboard or use 16 pads49-key Fatar TP8 with polyphonic aftertouch
Pad Section16 pads with 4 mode buttons (Notes / Scale / Chords / Trigger)No pads
Play ButtonsMono, Latch, Arp, Seq buttons + Tempo dial + Play buttonPitch Bend wheel, Mod wheel, Octave Up/Down, Chord, Mono, Latch, Seq/Arp, Macro buttons
PANEL buttonYes — accesses panel parameter overviewSHIFT + ENTER instead
Pedal InputsNoneSustain pedal + Control pedal inputs
MicroSD OrientationInsert with contacts facing DOWNInsert upside down, contacts facing UP
Security SlotPhysical Kensington-type security receptacle on rear panelNo security slot
Macro ButtonsNot available6 freely-programmable macro buttons
📝 The Desktop's 16 pads each have a configurable mode per layer. The pad configuration is saved with each patch. When switching layers, the pads reflect the active layer's configuration.

Desktop Pad Modes

Pad ModeBehavior
NotesEach pad triggers a specific note
ScalePads play notes within a selected scale
ChordsEach pad triggers a chord
TriggerPads trigger sequences or arpeggiator patterns

Tempo and Play (Desktop)

The Tempo dial sets the BPM for the selected sound program, affecting the arpeggiator, sequencer, beat-synced LFOs, and tempo-based effects. Press the Play button to start or stop the arpeggiator or sequencer.

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3. Rear Panel Connections

🖥️ Desktop rear panel layout (left to right)
  1. Power Supply Jack & Power Switch
  2. Headphones Output with Volume control (¼" TRS)
  3. Stereo Audio Outputs & Stereo Audio Inputs (2× TS mono jack each)
  4. CV/Gate/Clock Connections
  5. MIDI Thru, MIDI Out, MIDI In jacks (5-pin DIN)
  6. USB 2.0 Connections (Computer USB + Controller USB)
  7. MicroSD Card Port & Physical Security Receptacle

Audio Output

The Iridium is a stereo instrument — use 2× TS mono jack cables. The audio outputs deliver unbalanced line level. Use TS mono plugs, NOT TRS stereo plugs (balanced inputs may not work correctly). Connect to a Line/Aux/Tape input on your mixer or interface — never to mic or phono inputs.

Audio Input

Stereo audio input (2× mono jacks) feeds external audio into the Iridium's signal path for real-time processing or recording via the Audio Recorder on the Global page.

CV/Gate/Clock

Eurorack-compatible CV/Gate inputs allow external control of the Iridium from modular systems. Sync with Clock In/Out. All CV settings are configured in Global → Settings → CV.

USB Connections

MicroSD Card

Use FAT or FAT32 formatted cards. Desktop: insert with contacts facing DOWN. Used for OS updates, sample/wavetable import, patch export/import. USB drives (FAT/FAT32) work in all the same scenarios except full system init and rescue boot — those still require MicroSD.

⚠️ Startup takes approximately 10–15 seconds. Do NOT press and hold Global, Master, and Load buttons simultaneously during startup — this activates a special mode. Turn amp volume down before connecting/disconnecting power.
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4. Basic Operation

Power On/Off

Press the Power switch on the rear panel. Boot takes approximately 10–15 seconds. Press again to power off.

Master Volume

The Master Volume dial controls overall output level, including the headphones output. This is a global setting.

Panic Function

Press the Semitone/Octave dials for Oscillator 1 and 2 simultaneously to send All Notes Off, stopping all playing voices.

Loading Programs

For Split or Layered sounds, when loading via the Load button an option appears to load into the current layer only, preserving the other layer.

Load Page Actions Menu

ActionFunction
ImportImport sound programs from MicroSD or USB
ExportExport current sound program + all related samples to MicroSD or USB (preserves folder structure)
DeleteDelete a range of sound programs (irreversible)
Rebuild CacheRebuild internal data cache if problems occur
InitInitialize current sound to default (does not overwrite stored program)
FavoritesManage a list of favorite sounds accessible from Perform mode

Saving Programs

  1. Press Save (lights red).
  2. Tap the sound name to open virtual keyboard — up to 32 characters.
  3. Tap Bank name to assign or create a bank.
  4. Tap Author name to assign or create an author.
  5. Assign up to 4 Attributes (strongly recommended for finding sounds later).
  6. Select target program number with Prev/Next or dial.
  7. Tap Save to confirm.
⚠️ Saving overwrites the target location permanently. Back up sounds regularly using Export.

Mode Page Buttons

ButtonFunction
OSC 1 / 2 / 3Oscillator display pages (Pitch & Tools / Mix / Timbre tabs)
FILTERSDual Filters, Digital Former, and Routing
ENVELOPESAmp, Filter 1 & 2, Free 1/2/3 envelopes
LFOs6 LFOs
MODModulation Matrix & Komplex Modulator
EFFECTSEffects slots 1–5
MASTERLevels, Compressor, Voice controls
PERFORMFavorites, Arpeggiator, Sequencer, XY pads, Notes/Scales/Chords
GLOBALScope, Pitch, Audio, MIDI, Settings, System
LOAD / SAVELoad and Save mode pages
LAYER 1 / 2Switch active layer
📝 Press a mode button multiple times to cycle through its tabs.
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5. Sound Layers & Display

Dual Layer Mode

The Iridium supports two independent sound layers that can be played simultaneously as:

Both layers share the maximum 16-voice polyphony. Switch between layers using the Layer 1 / Layer 2 buttons on the touchscreen display (Desktop) or dedicated buttons (Keyboard). The active layer button is illuminated.

Touchscreen Display Layout

The lower portion of the display always shows the same overview:

Editing Parameters

A vertical bar in the encoder display shows the original value from the loaded patch. Turning a dial clockwise increases value; counterclockwise decreases. Bipolar parameters pause briefly at zero to aid precise editing.

📝 Tapping any parameter opens a pop-up menu with options for: Normal / Fine / Super Fine resolution, Set Default, Set Last Loaded, Modulations, and MIDI Learn CC.
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6. Oscillator Section

The Iridium provides three oscillators per voice (OSC 1, 2, 3), each independently assignable to one of five synthesis types:

Wavetable Waveform Particle (Granular) Resonator Kernel

Select the synthesis type by pressing the corresponding button in the Oscillator section. Kernel mode is activated by pressing Wavetable + Waveform simultaneously. Each model has its own color — the entire oscillator section illuminates in that color when selected. Pressing an already-active model button mutes that oscillator.

Each oscillator page has three tabs: Pitch & Tools, Mix, and Timbre, plus a fourth tab showing the current model.


6a. Wavetable Oscillator Turquoise

A wavetable is a table of single-cycle waveforms. Wavetable synthesis allows stepping through or sweeping across waveforms via modulation — creating dramatic timbral changes impossible with static sample playback.

Panel Parameters

ParameterRange / Function
Semitone / OctavePitch in semitone steps. Hold dial while turning for octave steps. Default: 0.
Fine PitchFine-tune within ±1 semitone. Creates chorus-like effect between detuned oscillators.
SpectrumTransposes the spectral envelope independently from pitch. Negative = down, positive = up. Default: 0.
NoisyAdds noise character to the oscillator (spectrum unaffected).
PositionSets the start point within the wavetable. 0 = first wave, max = last wave.
FXSaturation/gain amount. 0 = clean. Higher values add distortion. Type set in Timbre tab.
TravelCyclic movement through the wavetable. Positive = forward, negative = backward. 0 = stopped.

Pitch & Tools Tab (Display)

ParameterFunction
Min Note / Max NoteLimits the keyboard range this oscillator responds to. Enables quasi-splits within a single layer.
PB RangePitch bend range in semitones, -24 to +24. Negative values invert pitch bend direction. Default: +12.
Pitch KeytrackHow much pitch follows MIDI note. Reference: C3 (note 60). 100% = 1:1. Default: 100%.
PitchVarSimulates analog pitch variation (component tolerances). Each oscillator of each voice gets a random coefficient at startup. 0 = off. Default: 0.17.
Mono RetrigIf Yes, forces retrigger when previous note is still in release phase. Default: No.
Tools buttonCopy parameter settings from another oscillator to this one.

Mix Tab (Display)

ParameterFunction
Osc VolVolume of this oscillator. Default: Osc 1 = 0dB, Osc 2 & 3 = -inf.
Osc PanStereo panning position. Default: Center.
Osc DestSignal routing: Main (through dual filter + DF + VCA), VCA (bypass filters), or DF/Fil split (e.g., DF 30 Fil 70). Default: Main.

Timbre Tab (Display)

ParameterFunction
WavetableSelects factory or user wavetable. Can be modulated — each voice can use a different wavetable if source is polyphonic (e.g., Rand Trig, Voice Index).
PositionSame as panel parameter.
TravelSame as panel parameter.
Travel ModeCycle, Global Cyc., Sync (tempo-locked), One Shot, Ping Pong, Global P.P. Default: Ping Pong.
SpectrumSame as panel parameter.
BrillianceSharpens spectral peaks when Spectrum is transposed. Subtle effect. Default: 0.
Keytrack (Spectrum)How much the spectrum follows pitch. 0% = formants fixed (good for speech/vocals). 100% = follows pitch. Default: 100%.
LimitWavetable interpolation at Travel end: Wrap (smooth blend) or Limit (hard, like vintage Waldorf). Default: Limit.
PhaseInitial phase in degrees. Maximum = free-running (like hardware oscillator).
NoisySame as panel parameter.
FX TypeOff, Reduce (sample reduction), Truncate (bit reduction), Drive (saturation), Gain (level boost). Default: Drive.
ModeNormal (highest quality), Legacy (vintage Waldorf character), Harsh (non-harmonic components), Dirty (digital aliasing). Default: Normal.
SteppedWave interpolation: Smooth, Stepped (no interpolation), 2/4/8 Steps. Default: Smooth.

Tools Button (Wavetable Creation)

ToolFunction
TalkType word(s) via virtual keyboard → synthesized as a wavetable (speech synthesis)
Analyze AudioSelect any audio file → automatically synthesized as a new wavetable
Load Single CycleLoad a single-cycle .wav/.aif file (200–1024 samples ideal). Creates an 8-position wavetable morphing to sine.
Import from .wavCreate wavetable from .wav/.aiff with constant sample period (64–4096, many synths use 2048)
Load WavetableImport wavetable from Flash/MicroSD/USB for exchange with other Iridium users
Save WavetableExport current wavetable to Flash/MicroSD/USB
💡 Free single-cycle waveforms available at: www.adventurekid.se/akrt/waveforms
💡 Wavetable selection itself can be modulated as a polyphonic target — each voice uses a different wavetable when the modulation source is polyphonic (Voice Index, Rand Trig, etc.). This opens an entirely new dimension of synthesis.
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6b. Waveform Oscillator Green

Classic analog-modeled oscillator with traditional waveforms plus a multi-oscillator stack (up to 8 kernels) for supersaw-type sounds.

Panel Parameters

ParameterRange / Function
Semitone / OctavePitch in semitone steps. Hold + turn for octave steps.
Fine PitchFine-tune in 1/128th semitone steps.
CountNumber of oscillator kernels (1–8). Values between integers blend in an additional kernel at reduced level. Use for supersaw-type stacking.
DetuneDetunes the stacked kernels when Count > 1.
ShapeSawtooth, Sine, Triangle, Square, Pink Noise, White Noise, Pings, Geiger.
WarpModifies the selected waveform: Saw → double saw to square; Sine → soft saw variants; Triangle → saw variants; Square → pulse width; Noise → filtered/pitched variants; Pings/Geiger → noise character.
SyncOscillator hard sync (all shapes except noise). Higher settings create more complex timbres.

Timbre Tab (Display) — Additional Parameters

ParameterFunction
StereoStereo spread of stacked kernels when Count > 1. Center = mono stack; higher = wide stereo. Default: 0%.
Semitone 1–4Individual pitch offset for each of the first 4 kernels (±12 semitones). Kernels 5–8 mirror 1–4.
PhaseRunning (free-running, analog behavior) or Reset (retrigger at phase 0 each note — useful for drums). Default: Running.
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6c. Particle Generator (Granular/Sample) Blue

The Particle Generator plays back audio samples in two modes: standard sample playback and granular synthesis. It can use a single sample or multi-samples mapped across the keyboard.

Sample Sources

📝 Supported formats: WAV or AIFF/AIFC (stereo or mono), any sample rate and bit depth. Recommended: 44.1 kHz to preserve original pitch.

Key Panel Parameters

ParameterFunction
Semitone / OctavePitch offset in semitone steps. Hold + turn for octave steps.
Fine PitchFine-tune within ±1 semitone.
PositionStart point for sample playback or grain position in granular mode.
Grain Size(Granular mode) Size of each grain — from very small (glitchy/noisy) to large (smooth).
Spray(Granular mode) Random offset of grain start position — adds shimmer and texture.
Density(Granular mode) Number of overlapping grains playing simultaneously.
💡 See the Appendix section "A Short Introduction to Granular Synthesis" for conceptual background. Live Granular mode enables real-time granular processing of any external audio signal fed through the audio input.
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6d. Resonator Orange

The Resonator uses physical modeling principles to simulate the resonant behavior of vibrating objects (strings, tubes, membranes). It imparts strong harmonic coloring based on physical dimensions and material properties.

Key Parameters

ParameterFunction
Semitone / OctaveBase pitch of the resonating structure.
Fine PitchFine-tune the resonant frequency.
TuneContinuous pitch control of the resonator model.
StructurePhysical model type — affects the harmonic series and resonance character.
ExciterType of input signal driving the resonator (noise burst, impulse, etc.).
BrightnessHigh-frequency content of the input signal driving the resonator.
DecayResonance decay time — longer values sustain the "body" sound.
Inner LossInternal damping of the resonating structure — simulates material absorption.
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6e. Kernel Synthesis Purple

Kernel Synthesis is activated by pressing Wavetable + Waveform simultaneously. It combines multiple synthesis engines in a complex, layered oscillator architecture — capable of FM, ring modulation, wave folding, and other advanced interactions between up to 6 kernel oscillators within a single Iridium oscillator slot.

Kernel Architecture

Modulation Types Between Kernels

TypeDescription
FMFrequency modulation — classic FM synthesis between kernels
AMAmplitude modulation
Ring ModRing modulation between two kernels
Wave FoldWavefold processing for complex harmonic generation
FilterOne kernel filters another
💡 Kernel synthesis is the most complex synthesis mode. Use the Presets available for each synthesis type as starting points to explore Kernel's capabilities.
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6f. Oscillator Mixer (OSC MIX)

The OSC MIX section balances the output levels of all three oscillators before they enter the filter section. Each oscillator can also be individually routed (via Dest parameter in the Mix tab) to: Main signal path, directly to VCA (bypassing filters), or split between Digital Former and Dual Filter sections.

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7. Dual Filter Section

The Iridium features two independent analog-modeled filters per voice, accessible via the FILTERS mode button. Filters can be configured in various routing arrangements.

Filter Types (per Filter)

Filter TypeCharacteristics
Low Pass (LP)Passes frequencies below cutoff; attenuates above. Various slopes available.
High Pass (HP)Passes frequencies above cutoff; attenuates below.
Band Pass (BP)Passes frequencies around cutoff; attenuates above and below.
NotchAttenuates a narrow band of frequencies around cutoff.
Various slopes12dB/oct, 24dB/oct, and other models depending on filter type selection

Key Filter Parameters

ParameterFunction
Cutoff 1 / 2Filter cutoff frequency. Selection dial controls Cutoff 1 on the Filter page. Range: 0–127.
Resonance 1 / 2Emphasizes frequencies near the cutoff. High settings can cause self-oscillation.
Filter DriveInput gain/saturation into the filter — adds warmth and harmonics.
KeytrackTracks filter cutoff to keyboard pitch. 100% = cutoff tracks pitch 1:1.
Env AmountHow much the filter envelope modulates the cutoff frequency.
RoutingSerial (Filter 1 → Filter 2), Parallel (both process same signal), or other configurations.
Filter TypeSelect filter model from available types.
📝 See the Appendix section "Filter Introduction" for background on filter design and how different filter types affect sound character.
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8. Digital Former Section

The Digital Former is a dedicated digital signal processor placed in the signal chain alongside the Dual Filter. It provides additional filter models and effect algorithms not available in the analog filter section.

Digital Former Models (selection)

ModelDescription
Low Pass / High Pass / Band PassDigital filter variants with different character from the analog filters
Comb FilterCreates resonant peaks at harmonically related frequencies — metallic, pitched character
WaveshaperNon-linear distortion / waveshaping for harmonic enrichment
Bit CrusherLo-fi digital degradation via bit reduction
Sample Rate ReducerReduces effective sample rate for aliasing artifacts
Frequency ShifterShifts all frequencies by a fixed amount (not pitch transposition) — inharmonic effects
Ring ModulatorAmplitude modulation with an internal carrier oscillator

The Digital Former can receive signal at a configurable ratio relative to the Dual Filter (set via Osc Dest parameter — e.g., DF 30 Fil 70).

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9. Envelopes Section

The Iridium provides 6 envelopes per voice, accessible via the ENVELOPES mode button:

Envelope Parameters

ParameterFunction
AttackTime to reach peak level from note-on. Logarithmic or linear shapes available.
DecayTime to fall from peak to Sustain level.
SustainLevel held while key is pressed (after Decay).
ReleaseTime to fall to zero after key-off.
DelayTime before the Attack phase begins.
HoldTime the envelope holds at peak before Decay begins.
SlopeShape of the attack/decay curves (linear, exponential, logarithmic).
SingleTrigIf active, envelope does not retrigger during legato playing in Mono mode. Use for classic 1970s-style solo sounds.
VelocityAmount that note velocity modulates envelope amplitude.
📝 SingleTrig settings can be freely mixed across all 6 envelopes. An envelope with SingleTrig ON will not retrigger in legato mono mode; one with SingleTrig OFF will retrigger on every note.
💡 Envelope shapes can be edited graphically by tapping directly on the envelope display and dragging the breakpoints.
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10. LFO Section

The Iridium provides 6 LFOs per voice, accessible via the LFOs mode button. Each LFO can be independently configured.

LFO Parameters

ParameterFunction
ShapeSine, Triangle, Sawtooth, Reverse Saw, Square, Random (S&H), Smooth Random
SpeedLFO frequency. Can be free-running or tempo-synced.
SyncSync to internal/external tempo in musical values (1/32, 1/16, 1/8, etc.)
PhaseStarting phase of the LFO waveform.
DelayTime before the LFO starts after note-on (useful for delayed vibrato).
FadeTime for LFO to fade in to full depth after note-on.
ClockedWhen enabled, LFO speed is expressed in musical time values relative to BPM.
KeyTrigResets LFO phase on each new note when enabled.
MonoAll voices share a single LFO phase (global LFO) vs. each voice has its own.
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11. Effects (5 Slots)

The Iridium provides 5 independent effect slots, accessible via the EFFECTS mode button. Each slot can be assigned an effect type independently.

Available Effect Types (selection)

EffectDescription
ChorusClassic modulated delay for width and thickness
FlangerShort modulated delay with feedback for metallic, jet-like sweeps
PhaserAll-pass filter cascade for sweeping phase cancellation effects
DelayTempo-syncable digital delay with feedback, filter, and stereo spread
ReverbAlgorithmic reverb: Room, Hall, Plate, and other models
DistortionOverdrive/distortion for harmonic saturation
EQEqualizer for tonal shaping
CompressorDynamic range compression/limiting
Lo-FiBit crusher, sample rate reduction, vinyl/tape simulation
ResonatorResonator-based effect (different from oscillator Resonator mode)
Ring ModulatorInharmonic amplitude modulation effect
📝 Effects are patch-level and saved with each program. Effect parameters can be assigned as modulation targets in the Modulation Matrix.
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12. Modulation Matrix & Komplex Modulator

The Iridium's modulation system is accessed via the MOD mode button. It consists of two parts: the Modulation Matrix and the Komplex Modulator.

Modulation Matrix

A traditional matrix-style modulation system where any source can be routed to any destination with a specified amount. Setting up modulations can be done from the MOD page or by tapping any parameter and selecting Modulations from its pop-up menu.

Common Modulation Sources (selection)

SourceDescription
Envelope 1–6Any of the six envelopes
LFO 1–6Any of the six LFOs
VelocityNote velocity (0–127)
AftertouchMonophonic or polyphonic aftertouch
Mod WheelMIDI CC 1
Pitch BendPitch bend wheel
KeytrackMIDI note number as modulation source
Voice IndexEach voice gets a unique value — useful for polyphonic variation
Rand TrigRandom value generated at each note trigger
Komplex ModOutput of the Komplex Modulator
CV 1–4External control voltage inputs
MIDI CCAny MIDI continuous controller
💡 Full modulation source and destination lists are in the Appendix of this manual (Modulation Sources and Destinations section).

Komplex Modulator

The Komplex Modulator is a multi-stage, programmable modulation generator that goes far beyond a standard LFO or envelope. It can create complex, evolving modulation shapes by combining multiple stages with different curves, times, and levels. Its output can be used as a modulation source in the Modulation Matrix.

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13. Master Mode

Accessed via the MASTER mode button. Contains three tabs: Levels, Pitch/Voices, and additional controls for the two sound layers.

Levels Tab

ParameterFunction
Layer 1 / Layer 2 VolumeIndividual volume balance between the two layers
Layer 1 / Layer 2 PanStereo panning of each layer
CompressorMaster output compressor/limiter
Main Output LevelOverall output gain

Pitch / Voices Tab

ParameterFunction
TransposeGlobal pitch transposition in semitones
TuneGlobal fine-tune in cents
Layer ModeSingle (one layer), Layer (both layers simultaneously), Split (keyboard split)
Split PointKeyboard split note when in Split mode
Voice AllocationHow polyphonic voices are distributed between Layer 1 and Layer 2
UnisonoStack multiple voices per note for massive detuned sounds
Unisono DetuneDetune amount between stacked unisono voices
Glide (Portamento)Portamento time for smooth pitch slides between notes
Glide ModeLegato (only slides when notes overlap) or Always (slides on every note)
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14. Perform Mode

Accessed via the PERFORM mode button. Contains multiple tabs for live performance tools.

Favorites Tab

A curated list of up to 64 favorite sound programs for quick live access. Managed from the Load page → Favorites button.

Arpeggiator Tab

ParameterFunction
ModeUp, Down, Up-Down, As Played, Random, Chord
Tempo / BPMArpeggiator speed. Can sync to external MIDI clock.
Step LengthNote value per step (1/32 to 1/1, including dotted and triplet values)
Octave RangeHow many octaves the arpeggio spans (1–4)
GateNote length as percentage of step length
VelocityVelocity of arpeggiated notes (or As Played)
Hold / LatchHold notes active while arpeggiator runs

Step Sequencer Tab

ParameterFunction
StepsNumber of active steps (1–16)
Step NoteIndividual pitch per step
Step VelocityIndividual velocity per step
Step LengthIndividual gate length per step
Tempo / BPMSequencer speed
DirectionForward, Backward, Ping-Pong, Random

XY Pads Tab

Two XY touchpads that can each be assigned to two modulation destinations simultaneously. Excellent for expressive real-time sound morphing.

Notes / Scale / Chords Tab

Configure the behavior of the 16 pads on the Desktop (and of equivalent chord/scale functions on the Keyboard). Includes scale selection, key, and chord voicing settings.

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15. Global Mode

Accessed via the GLOBAL mode button. Contains system-wide settings across multiple tabs. Changes here affect the entire instrument, not individual patches.

Scope Tab

Configure the oscilloscope/analyzer display in the lower left of the touchscreen. Options: VUs (Voices & Main), VUs (In & Main), Scope (waveform), Analyzer (lin), Analyzer (log), MIDI Monitor (Internal + Incoming), CV Inputs.

Pitch Tab

SettingFunction
Master TuneGlobal fine-tune (Hz) — adjust for playing with other instruments
Pitch Bend RangeGlobal pitch bend range (can also be set per oscillator)
Pitch Button (Keyboard)Calibrate Pitch Bend wheel and Modulation wheel via Global → System → Calibrate → Wheels

Audio Tab

SettingFunction
Audio Input LevelInput gain for the stereo audio input
Audio Input RoutingRoute audio input through signal path or direct to Audio Recorder
Audio RecorderRecord audio from main output or audio input to internal Flash memory. Files available in Particle Generator.
Output FormatStereo output configuration

MIDI Tab

SettingFunction
MIDI ChannelReceive channel for DIN MIDI In (1–16 or Omni)
MIDI OutTransmit channel and what data is sent via MIDI Out / USB
USB MIDIEnable/configure Computer USB MIDI communication
MIDI ThruRoute incoming MIDI to MIDI Thru jack
Program ChangeRespond to incoming MIDI program change messages
MIDI ClockInternal (master), External (slave), or Auto
MIDI LearnAvailable per parameter via tap → MIDI Learn CC

Settings Tab

SettingFunction
CV SettingsConfigure CV 1–4 input scaling, range, and assignments
Button BacklightConfigure button illumination behavior (steady, blink, etc.)
ColorsCustomize oscillator section and button colors
Knob BehaviorJump, Catch-Up, or Relative mode for panel knobs
ScreensaverConfigure display screensaver timeout

System Tab

SettingFunction
Firmware UpdateUpdate OS from MicroSD card or USB drive
Factory ResetRestore all settings to factory defaults (requires confirmation)
CalibrateCalibrate Wheels, Control Pedal (Keyboard only), touchscreen
System InfoCurrent firmware version, serial number
Polytouch Keyboard(Keyboard only) Configure polyphonic aftertouch sensitivity
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16. Loading & Editing Samples

The Iridium has an internal Flash memory for storing samples, and supports loading from MicroSD card or USB storage devices. Samples are used by the Particle Generator oscillator.

Loading Samples

Sample Editing

FunctionDescription
Start / End PointsSet playback region within the sample
Loop PointsDefine loop start/end for sustained playback
Loop ModeForward, Ping-Pong, or Off
TunePitch offset for the sample
Root NoteThe MIDI note at which the sample plays at its original pitch
ReversePlay sample backward

Audio Recorder (Global → Audio)

Record audio from the main output or audio input directly to internal Flash memory. Recorded files appear in the sample browser and can be loaded directly into the Particle Generator — enabling real-time sampling and immediate use in synthesis.

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17. Appendix

Firmware Update Procedure

  1. Download latest firmware from waldorfmusic.com/iridium.
  2. Copy firmware file to a FAT/FAT32 formatted MicroSD card or USB drive (root directory).
  3. Power off Iridium. Insert card/drive.
  4. Power on. Navigate to Global → System → Firmware Update.
  5. Follow on-screen instructions. Do not power off during update.

Wavetable Synthesis Basics

A wavetable is a collection of single-cycle waveforms arranged in a table. Unlike sample playback, wavetable synthesis lets you sweep through these waveforms continuously, creating evolving timbres. Each waveform represents a unique harmonic spectrum. The Iridium extends classic wavetable synthesis by allowing the wavetable selection itself to be modulated polyphonically, adding an extra dimension of sound design.

Waveform Oscillator Basics

Classic analog synthesizer waveforms are built from harmonic series. Sawtooth = all harmonics descending in level. Square/Pulse = odd harmonics only (hollow/metallic character). Triangle = odd harmonics with low magnitudes (softer than square). Sine = fundamental only (purest, no harmonics). The Iridium's Warp parameter morphs between related waveforms within each shape type.

Granular Synthesis Basics

Granular synthesis chops audio samples into tiny "grains" (typically 1–100ms), then plays them back with control over their density, overlap, position, size, and scatter. Small grain sizes create noise and texture; larger sizes reveal the original sample content. Controlling grain position against time allows time-stretching without pitch change. The Iridium's Particle Generator's Live Granular mode applies this in real time to external audio.

Filter Basics

Filters attenuate or boost specific frequency ranges relative to a cutoff frequency. Low-pass filters (most common in synthesis) remove high frequencies for a warmer sound. Resonance adds emphasis at the cutoff frequency. High resonance causes a pronounced peak; at extreme settings the filter self-oscillates (generates a pure sine tone at the cutoff frequency). Envelope modulation sweeps the cutoff over time for the classic "filter sweep" effect fundamental to subtractive synthesis.

FAQ

QuestionAnswer
No sound from Iridium?Check Master Volume dial, audio cable connections (use TS mono cables, not TRS). Check that the oscillator is not muted. Check that an oscillator model is selected and lit.
Iridium not receiving MIDI?Check MIDI channel in Global → MIDI. Ensure cable is connected to MIDI IN. Verify Omni mode if unsure of channel.
USB MIDI not working?Ensure you're using the Computer USB port, not Controller USB. Verify USB 2.0 cable and port.
MicroSD card not recognized?Verify FAT/FAT32 format. Desktop: contacts face DOWN. Keyboard: contacts face UP.
Knobs not responding as expected?Check knob behavior setting (Jump/Catch-Up/Relative) in Global → Settings.
Sample not at correct pitch?Verify Root Note setting in sample editor matches the recorded pitch of the sample.
Wavetable import not working?Verify FAT/FAT32 format on storage device. Check that file is .wav or .aiff. Ensure MicroSD inserted correctly.

Technical Specifications

SpecIridium Desktop
Audio Outputs2× TS mono jack, unbalanced line level
Audio Inputs2× TS mono jack, unbalanced
Headphones¼" TRS stereo, with independent volume control
MIDI5-pin DIN In / Out / Thru
USB2× USB 2.0 (Computer + Controller)
CV/Gate/ClockEurorack-compatible (0–5V)
StorageMicroSD (FAT/FAT32), USB drives (FAT/FAT32)
PowerExternal power supply (included)
OSRev. 3.x (July 2023) — updateable

Support

Waldorf Music website: waldorfmusic.com/iridium
Manual source (Pastebin): https://pastebin.com/qqU9bsXi

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fortinable.com Manual Library — Waldorf Iridium Desktop — Rev. 3, September 2023