The Waldorf Iridium Keyboard is a premium-grade all-digital flagship synthesizer based on the architecture of Waldorf's hybrid Quantum. While the Quantum features eight analogue/digital hybrid voices, the Iridium boasts 16 all-digital voices, maintaining the same powerful sound engine but with several key improvements. The keyboard version follows the desktop Iridium model, adding a four-octave Fatar TP/8SK keybed with polyphonic aftertouch - a significant enhancement over the (initial) Quantum's five-octave semi-weighted keyboard with channel aftertouch.

This powerful synthesizer combines multiple synthesis types, including wavetable, granular, virtual analogue, physical modeling, and FM synthesis. With its comprehensive modulation options, dual-layer architecture, and high-quality effects, the Iridium represents Waldorf's pinnacle of digital sound design capabilities.

Design and Build

More compact than the Quantum, the Iridium Keyboard measures 851 x 355 x 110mm and weighs 14kg (compared to the Quantum's 1006 x 401 x 131mm and 17.8kg). The front panel features a full-color touchscreen at the center, surrounded by dedicated controls for oscillators, filters, envelopes, LFOs, and effects. The layout has been tweaked from the Quantum, with more knobs for the dual digital filters and the addition of seven programmable Macro buttons for custom shortcuts. The one-knob-per-function control layout includes seven encoders on each side of the touchscreen for intuitive parameter access, alongside pitch and mod wheels.

Sound Engine

The Iridium features a true stereo signal path throughout (unlike the Quantum, which would mix stereo signals to mono when using its analogue filters). Each patch consists of two complete layers that can be stacked, split, panned, or played bi-timbrally via different MIDI channels.

Each layer includes:

• Three oscillators (any type can be loaded into each slot)
• Three multi-mode filters
• Six envelopes
• Six LFOs
• A Komplex modulator
• Up to five effects

Synthesis Types

The Iridium offers five oscillator types, each with its own unique capabilities:

1. Wavetable: Waldorf's specialty featuring 85 factory wavetables (each with 128 waveforms), plus the ability to import or generate wavetables from analysis of WAV files or even speech synthesis.

2. Waveform: Virtual analogue engine with the standard waveforms, eight-voice unison ("kernels"), chord/interval capabilities, PWM-style waveshaping, and built-in sync.

3. Particle: Combines sample playback and granular synthesis with a 1GB sample library on 4GB internal flash memory. Offers multi-sample capabilities with key and velocity splits, plus granular mode with up to eight grains that can be manipulated in various ways.

4. Resonator: Physical modeling using noise sources or samples processed through resonant filter banks, capable of creating plucked strings, wind instruments, bells, percussion, and experimental sounds.

5. Kernels: A semi-modular system (introduced in OS 2.0) allowing up to six kernels (oscillators) to be combined using various modulation types including AM, FM, phase modulation, ring modulation, and phase distortion.

Filters

Three multi-mode digital filters are available per voice:

• Two main filters in the Dual Filter section with multiple filter models (SVF, Raiser, Largo, Nave, PPG, and Quantum)
• A "Digi Former" that can operate as a filter or provide other processing like overdrive, comb filtering, bit crushing, and ring modulation

The filters can be arranged in various configurations, with flexible routing options for the oscillators. Filter types include 12dB or 24dB Lowpass/Highpass/Bandpass with optional saturation or "dirtiness." The Dual Filter section can be controlled independently or linked, while all filters maintain true stereo signal path throughout the instrument.

Modulation

The extensive modulation options include:

• Six LFOs per layer with speeds from 240 seconds/cycle to 100Hz
• Six envelopes (DADSR with variable curves and looping)
• Komplex modulator with two multi-stage waveforms that can be blended and modified, allowing for custom shape LFO or envelope creation
• 40-slot modulation matrix with additional control amount per slot

Display Features

The touchscreen provides extensive visual feedback, including:

• Real-time visual feedback of parameter changes
• Komplex Modulator curve drawing
• Envelope progression display
• Wavetable visualization
• Voice usage and level VU meters
• Audio signal analyzers

Effects

Each layer can have up to five effects chosen from:

• Phaser
• Chorus
• Flanger
• Delay
• Reverb
• EQ
• Overdrive
• Compressor

Additionally, there's a global one-knob compressor and bass-boost option.

Keyboard

• 49-key FATAR TP/8SK semi-weighted keyboard
• polyphonic aftertouch
• variable attack and release sensitivity

Performance Features

• Seven programmable Macro buttons
• 4x4 silicon pad matrix (on the touchscreen) for launching notes, chords, arpeggios, and sequences
• Favorites page for quick access to presets (six sets of 20 presets)
• 32-step sequencer with lanes for pitch, note length, velocity, and eight controller lanes
• Arpeggiator with 31 preset rhythm patterns
• X/Y pad using the touchscreen
• Scala tuning file support and built-in tuning editor
• Extensive preset library with capacity for up to 7000 patches (1680 factory sounds programmed by various sound designers)
• Compatible with Quantum patches
• MPE (MIDI Polyphonic Expression) support

Connectivity

• Stereo audio inputs and outputs (two outputs and two inputs, unbalanced TS quarter-inch jacks)
• Headphone output with dedicated volume control
• Eight CV connectors (3.5mm jacks) including CV inputs, Gate In, and Trigger In
• Clock In and Clock Out
• MIDI in, out and thru (DIN)
• Sustain and control pedal inputs
• USB connector for computer connection
• USB host socket for class-compliant MIDI controllers or storage
• Micro-SD card slot for file transfers, backups, and OS updates

Technical Specifications