Heisenberg is a four-operator phase-modulation synthesizer (PM), offering FM-like tones through flexible sound design capabilities.
Flexible modulation matrix for complex routing
Assignable envelopes for dynamic control
Multiple LFOs for modulation
Multimode filter for tone shaping
Ideal for digital pianos, bells, basses, and experimental textures.
Global Controls
Global Controls
Control
Description
Mode
Play mode:
Polyphone: Multiple notes can play simultaneously
Legato: New notes retrigger envelopes only when previous note is released
Monophone: Only one note plays at a time
Unisono
Amount of unison voices per note (1 to 4). Values > 1 create multiple voices for fatter, wider sounds
Detune
Tuning of unison voices in semitones (0 to 1 semitones). Creates detuning between voices when unisono > 1
Spread
Stereo width of unison voices (-100 to 100%). 0 = centered, positive = spread right, negative = spread left
Glide
Portamento time between notes (0 to 5000 ms). In Mono/Legato mode, notes glide if they overlap; in Polyphone mode, notes glide if they don't overlap
Tune
Global pitch adjustment in semitones (-12 to +12 semitones)
Velocity
Global velocity sensitivity multiplier (0 to 100%). Controls how much note velocity affects loudness
Volume
Overall output level (0 to 1, equivalent to -∞ to 0 dB)
Active
Enable/disable the device. When disabled, the synthesizer is silent
Detune Mode
Controls how operator detune is displayed: Semitone (1) or Ratio (2) mode (1 to 2). This affects the display only, not the audio behavior
Micro-tuning
Optional micro-tuning reference. Links to a micro-tuning device for alternative tuning systems
Operator (A–D)
Each operator can act as either a carrier (sound generator) or a modulator (affecting another operator’s sound). Every operator has individually controllable parameters.
Operator (A–D)
Control
Description
Wave
Choose waveform from 49 selectable waves like sine, square, sawtooth, triangle, etc.
Semitone/Ratio
Coarse pitch adjustment. Can be displayed as semitones (0 to 64) or frequency ratio, depending on operator detune mode setting
Offset
Fine pitch adjustment in Hz (-9999.99 to 9999.99 Hz)
Pitch
Enables the pitch envelope for this operator
The waveform significantly affects the character of modulation. Sine waves produce clean, harmonic sounds, while complex waves introduce richer overtones.
Phase Modulation
At the heart of the interface is the modulation matrix, where you define which operator modulates which.
Instead of altering pitch, PM changes a signal’s phase over time. When the phase of a carrier is modulated by another operator (the modulator), new harmonics are created, making the sound more complex or animated.
Unlike subtractive synthesis (which removes harmonics via filters), phase modulation adds harmonics through modulation. This results in metallic, bell-like, or digital textures that are difficult to achieve with analog-style filtering.
The matrix works like a grid:
Rows = Carriers (operators producing the final sound)
Columns = Modulators (operators modifying other operators)
Each cell in the matrix holds a value (e.g., 0.5 or 1.0) that determines how much one operator modulates another.
Example
In row A, column B, the value is “0.7”: This means B modulates A with a depth of 0.7
You can combine them freely:
A modulator can affect multiple carriers
A carrier can be affected by multiple modulators
Chained or circular modulations are possible: e.g., C -> B -> A or even A -> B -> C -> A (feedback)
Visual Analogy
Think of each operator as a light source
Modulation is like placing colored filters in front of that light
The more filters (i.e., modulators) in the chain, the more colorful, complex, or unpredictable the result becomes
Mix
Mix
Control
Description
Pan (left knob)
Stereo placement (-100 to 100). -100 = fully left, 0 = centered, 100 = fully right
Volume (right knob)
Audio output level of the operator (0 to 1, equivalent to -∞ to 0 dB). Only affects audible output, not modulation
These only affect the audible output, not modulation.
Default Behavior
When loading a new patch, only Operator A has Volume > 0 (audible)
Operators B, C, and D are muted (Volume = 0) by default and typically serve as modulators
Amplitude Modulation
Amplitude Modulation
Control
Description
Rows
Operators A–D and Filter Mod
Columns
Mod sources (Main ENV, ENV2, ENV3, LFO1, LFO2, Velocity)
Function
Controls how strongly each source modulates an operator's amplitude or the filter cutoff
Filter Mod
Bottom row controls how modulation sources affect the filter
Envelopes
Envelopes
Control
Description
Main ENV
Standard ADSR envelope. Always applied to overall gain, but can also be assigned to individual operators via the amplitude modulation matrix
ENV2 & ENV3
Freely assignable ADSR envelopes. Can be routed to operator amplitude, filter cutoff, or other destinations via the amplitude modulation matrix
Pitch Envelope
Dedicated pitch envelope. Can be enabled per operator to modulate pitch over time
Loop
All envelopes can loop for rhythmic or evolving modulation patterns
LFO
LFO
Control
Description
Waveforms
Selectable waveforms including sine, square, saw, triangle, parabola, etc.
Rate
LFO speed. When free-running: 0.01 to 500 Hz. When synced: quantized to bar time durations from 1/256 to 4/1 bars
Sync
Free-running or synced to host tempo. When synced, rate is quantized to one of 30 tempo-based values
Destinations
Can modulate pitch, amplitude, filter cutoff, etc. via the amplitude modulation matrix
