Krate Audio / Seraphis

Seraphis — User Manual

Spectral Organism Synthesizer

Introduction

Seraphis is a spectral organism synthesizer. Each voice is a cloud of 64 harmonic partials driven by a spectral-evolution layer, resonated through a continuous modal body, with a parallel granular atmosphere breathing alongside it. A family of slow autonomous life modulators — Brownian drift, breathing, tides, orbits — animates all of it, so nothing you play is ever static. The integrated Aether space engine (an infinite-tail reverb with shimmer, bloom, and spectral diffusion) sits inside the signal path rather than behind it: the space is part of the instrument, not an effect appended to it.

Seraphis is the ethereal counterpart to Ruinae. Where Ruinae is instability, chaos and aggression, Seraphis is emergence, resonance and weightlessness. It is built for textures, pads, drones, bells, choirs and cinematic atmospheres — sounds that move on their own and never quite repeat.

Formats: VST3 (Windows, macOS, Linux) and Audio Unit (macOS). One MIDI input, one stereo output.

Signal Flow

MIDI in
  │
  ▼
Harmonic Cloud ──── 64 additive partials per voice
  │                 (richness, inharmonicity, tilt, mutation, drift, per-partial envelopes)
  ▼
Spectral Morph ──── travels between up to 4 spectral states
  │                 (entropy, bloom, external position or autonomous spline travel)
  ▼
Continuous Body ─── modal resonator (Glass / Strings / Metal Plate / Chamber / Ice)
  │                 + a slow post-body decay cloud wash
  ▼
Granular Atmosphere (parallel layer: grains fed from the voice, blur, freeze)
  │
  ▼
Aether ──────────── the space engine, in the path: infinite FDN reverb,
  │                 shimmer taps, bloom stage, spectral diffusion, breath & tide
  ▼
Effects ─────────── tape saturation → spectral delay → spectral freeze → stereo stage
  │                 (width, wander, azimuth)
  ▼
Output ──────────── master gain → true-peak limiter (always on)

The five macros — Dream, Bloom, Dissolve, Gravity, Entropy — reach across every stage of this chain at once, and the life modulators run underneath it continuously. Both are described in their own sections below.

Interface Overview

The editor is a fixed 1000 × 700 window built organism-first: the entire window is a live view of the sound, and the controls orbit it.

Every control in the editor carries a tooltip — hover over anything to get a one-line description.

The Cloud View

Observe mode

The default. The constellation shows the loudest currently-sounding voice: partials rise and fall with their envelopes, drift sideways as the stereo field moves, brighten and dim with mutation, and travel vertically as morphing retunes them. With no note held, the view shows the selected morph slot’s spectrum at a reference pitch, so the display is never empty.

Edit mode — editing partials

Flip the toggle to EDIT and the constellation becomes editable:

Editing works with or without a note held — with no note sounding, authoring uses a fixed reference pitch. Edits reach an already-sounding voice immediately, absorbed through the morph engine’s own fade so there is never a click. Your authored states are saved with the project and with presets, and restored exactly.

Macros

The five macro rings are the intended playing surface of Seraphis. Each macro sweeps a curated set of targets across the whole engine — voice, space and effects at once. Two things are worth knowing about how they work:

  1. The deep parameters set the origin the macros travel from. Moving a drawer parameter moves the base a macro’s sweep starts at; the macro then adds its travel on top. The two never fight over a value.
  2. All macros default to neutral (0 for all, centre for Gravity). At neutral a macro contributes exactly nothing — the drawer parameters alone describe the sound.

Dream — “Purifies the harmonics, deepens the reverb and calms entropy”

Target Travel at full Dream
Cloud Inharmonicity → 0 (pure harmonic grid)
Cloud Gravity → 0
Cloud Mutation → 0
Morph Entropy → 0
Orbit Depth → maximum
Aether Mix 0.35 → 0.70
Aether Size Breath → 0.80
Aether Tide Depth → 0.80

Dream removes disorder from the spectrum while deepening the space and its slow breathing: at full Dream the cloud is a pure, weightless harmonic stack inside a living reverb.

Bloom — “Opens upper partials, shimmer and width; morphs toward brightness”

Target Travel at full Bloom
Cloud Tilt +9 dB/oct
Cloud Richness → 1.0
Cloud Stereo Spread → 0.95
Voice Width +30 %
Morph Position → slot B
Aether Shimmer Octave → 0.60
Aether Shimmer Fifth → 0.40
Aether Bloom Send → 0.60
Aether Width → maximum

Dissolve — “Melts the tone into granular fog, blur and slower envelopes”

Target Travel at full Dissolve
Atmosphere Level → maximum
Atmosphere Blur → 0.40
Cloud Attack 0.05 s → 2 s
Envelope Stage 0 2 s → 6 s
Envelope Stage 1 4 s → 9 s
Envelope Release 8 s → 10 s
Spectral Delay Mix → 0.20

Gravity — “Air-to-stone axis” (bipolar)

Gravity is the one bipolar macro: its centre is neutral, turning it down moves toward air, up toward stone.

Target Air (full down) Stone (full up)
Cloud Richness 0.95 0.25
Body Damping 0.0 0.50
Cloud Tilt +8 dB/oct −8 dB/oct
Aether Size 0.05 0.95

Entropy — “Decays order into jitter, detune and partial death and rebirth”

Target Travel at full Entropy
Morph Entropy 0.20 → 0.50
Cloud Drift Depth → 50 cents
Atmosphere Drift Depth → maximum
Stereo Wander Depth → 0.50

Header Controls

Control Range Default Notes
Gain 0 – 200 % (−80 dB … +6 dB) unity (centre) Overall output level of the whole instrument
Voices 1 – 16 8 Maximum simultaneous voices
Limit on/off on Tape-style output saturation. The true-peak limiter always stays on — this toggle only adds or removes the tape colouration in front of it
Seed Seed 1 – Seed 16 Seed 1 Random seed for drift, grains and reverb modulation; changing it re-rolls the texture without changing any parameter
Atmos Frz on/off off Suspend the atmosphere on its current material
Aether Frz on/off off Hold the reverb tail forever, conserving its energy
Spec Frz on/off off Capture and hold the current spectrum indefinitely
Presets — — Opens the preset browser

The three freeze switches in the header are duplicates of the same parameters on the Atmos, Aether and FX tabs, placed within reach while performing.

The Drawer: Cloud Tab

The harmonic cloud is the additive core — 64 partials per voice.

Parameter Range Default Description
Richness 0 – 100 % 60 % Number of active partials and how fast they roll off
Inharm 0 – 0.1 0.03 Stretches partials off the harmonic grid, piano toward bell
Tilt −12 – +12 dB/oct 0 Spectral slope: dark below zero, bright above
Mutation 0 – 100 % 25 % Rate of slow random re-weighting of partial amplitudes
Gravity −1 – +1 +0.2 Pulls partial ratios toward (or pushes away from) the pure harmonic grid
Drift 0 – 50 ct 0 Depth of the per-partial pitch drift, in cents
Drift Smth 0 – 100 % 50 % How slow and smooth the per-partial drift is
Spread 0 – 100 % 35 % Spreads the individual partials across the stereo field
Attack 0.05 – 30 s (log) 0.05 s Attack of each partial’s own envelope
Decay 0.05 – 60 s (log) 0.5 s Decay of each partial’s own envelope
Env Spread 0 – 100 % 0 % Staggers per-partial attack times so the cloud blooms in

Tip: Env Spread is what makes a chord “assemble” — with a slow attack and full spread, the partials enter one after another and the note builds itself in front of you (hear Bell Garden).

The Drawer: Morph Tab

The morph engine travels the cloud between up to four spectral states — factory spectra loaded into slots A–D, or your own states authored in Edit mode.

Parameter Range Default Description
Entropy 0 – 100 % 20 % Decays spectral order: amplitude jitter, phase smear, then partial death
Bloom 0 – 0.6 0 Delays high partials behind low ones so a morph blooms upward
Position 0 – 3 0 Where the sound sits between the spectral slots (0 = A, 3 = D)
Travel External / Spline External External follows the Position knob; Spline travels its own trajectory
Rate 0.0017 – 1 j/s (log) 0.0017 Speed of autonomous travel, in journeys per second
Sync Free / Synced Free Lock the morph travel rate to host tempo
Sync Note 1/16 … 8 Bars 1 Bar Length of one journey when Sync is on
Waypoint 0.5 – 30 s (log) 2 s Seconds between spline trajectory waypoints
States 2 / 3 / 4 2 How many slots the morph travels between
Slot A–D Sine Stack / Bell / Choir / Glass / Breath / Hollow / Metal / Organ / Vowel / Shimmer A: Sine Stack, B: Glass Factory spectrum loaded into each slot
Edit slot A / B / C / D A Which slot the cloud-view editing gestures write to

Position always spans 0–3 regardless of the States count. The ten factory spectra are starting material — beside the original five, Hollow is odd harmonics only (clarinet/square family), Metal a densely stretched ladder with every third partial dominant, Organ nine drawbar footages, Vowel a second, darker formant set than Choir, and Shimmer a faint fundamental under a sparse stretched high cluster. Any slot can be overwritten by hand in Edit mode, and authored slots survive saving and preset load exactly.

The Drawer: Body Tab

The cloud speaks through a continuous modal body — a physical resonator that can morph between materials.

Parameter Range Default Description
Material Glass / Strings / Metal Plate / Chamber / Ice Glass Resonant body the cloud speaks through
Resonance 0 – 100 % 70 % How long and how strongly the body rings
Damping 0 – 100 % 25 % Damps the body’s high modes, darker and shorter
Key Track 0 – 100 % 100 % How far the body retunes with the played note
Drive 0 – 4 1.0 Excitation level driven into the resonator
Mix 0 – 100 % 100 % Blend between the dry cloud and the resonated body
Cloud Mix 0 – 100 % 25 % Amount of the slow decay-cloud wash after the resonator
Cloud Decay 0.1 – 30 s (log) 4 s Decay time of the post-body wash
Cloud Size 0 – 100 % 100 % Size of the diffusion network behind the wash
Cloud Damp 0 – 100 % 30 % Darkens the post-body wash as it decays
Width 0 – 100 % 100 % Stereo width of the body output
Input AGC on/off on Normalizes the level feeding the resonator
Res Bypass on/off off Bypasses the modal resonator, keeping only the wash

Note that Mix defaults to 100 % — by default you hear the instrument through the Glass body. Turn Mix down for the raw additive cloud. Res Bypass with some Cloud Mix gives a body-less diffuse wash (hear Warm Static); turning Input AGC off lets the Drive knob genuinely overload the resonator (hear Iron Lung).

The Drawer: Atmos Tab

A granular layer running in parallel with the voice: grains are captured from the sound itself and re-scattered.

Parameter Range Default Description
Level 0 – 2 0.5 Level of the granular atmosphere layer
Blur 0 – 100 % 0 % Smears grain phase into fog, from material toward mist
Density 0.1 – 20 gr/s (log) 4 Grains per second; higher overlaps into a solid wash
Grain Sec 0.05 – 30 s (log) 4 s Length of each grain
Drift 0 – 100 % 30 % Depth of the per-grain pitch drift
Pan Spread 0 – 100 % 70 % Spreads the grains across the stereo field
Decorr 0 – 100 % 50 % Decorrelates the channels for a wider, more diffuse image
Freeze Mix 0 – 100 % 0 % Blend of the frozen spectrum into the grain stream
Freeze on/off off Suspend the atmosphere on its current material
Drift Smth 0 – 100 % 70 % How slow and smooth the per-grain pitch drift is
Drift Range 0 – 12 st 2 st Maximum per-grain pitch drift
Jitter 0 – 100 % 50 % Randomizes grain start timing, looser and less rhythmic
Position 0 – 30 s 1 s How far back in the capture buffer grains are read
Pos Spread 0 – 100 % 30 % Scatters the grain read positions around Position
Pitch −24 – +24 st 0 Transposes the grains
Pitch Spread 0 – 100 % 15 % Random pitch scatter between individual grains
Grain Env Hann / Trapezoid / Sine / Blackman / Linear / Exponential Hann Window shape of each grain, from soft to abrupt

Tip: Position at 0 reads grains right at the write head — the atmosphere shadows the voice almost live. Long positions with wide Pos Spread turn the buffer into a memory the instrument keeps digging through (hear Aftermath).

The Drawer: Aether Tab

The space engine. Aether sits inside the signal path — freezing it, breathing it and blooming it are part of playing the instrument.

Parameter Range Default Description
Mix 0 – 100 % 35 % Amount of Aether reverb in the output
Size 0 – 100 % 50 % Size of the space, from small chamber to impossible
Density 0 – 100 % 70 % Diffusion density; higher smooths the tail
Decay 0.5 – 60 s (log) 4 s Reverb decay time
Freeze on/off off Hold the tail forever, conserving its energy
Dimension 0 – 100 % 35 % Space character, from flat plate to N-dimensional hall
Damping 0 – 100 % 40 % Darkens the reverb tail as it decays
Pre-Delay 0 – 200 ms 0 Delay before the reverb starts
Mod Depth 0 – 100 % 25 % Depth of modulation inside the reverb delay lines
Mod Smth 0 – 100 % 60 % How slow and smooth the internal modulation is
Shim Oct 0 – 100 % 0 % Send into the octave-up shimmer tap inside the tail
Shim 5th 0 – 100 % 0 % Send into the fifth-up shimmer tap
Bloom Send 0 – 100 % 0 % Send into the bloom stage that reinforces held partials
Bloom Decay 0 – 100 % 50 % How long the bloom sympathetic resonance sustains
Spec Diff 0 – 100 % 0 % Smears the tail spectrally for an underwater character
Breath 0 – 100 % 20 % Depth of the slow breathing of the space size
Tide 0 – 100 % 20 % Depth of the very slow tidal drift through the space
Width 0 – 100 % 100 % Stereo width of the reverb tail

The Drawer: FX Tab

The final stage: saturation, a spectral delay, spectral freeze, and the stereo stage.

Parameter Range Default Description
Saturation 0 – 100 % 15 % Tape-style saturation on the output, a gentle ceiling
Delay Mix 0 – 100 % 0 % Amount of the spectral delay send in the output
Delay Time 0 – 2000 ms 250 ms Delay time when Sync is off
Spread 0 – 2000 ms 0 Spreads the delay time across frequency bins
Spread Dir Low → High / High → Low / Center → Out Low → High Direction the per-bin spread runs across the spectrum
Feedback 0 – 95 % 35 % Delay regeneration, internally compensated to stay stable at any Tilt
Delay Tilt −1 – +1 0 Biases the delay feedback toward low or high bins
Diffusion 0 – 100 % 30 % Smears the delay repeats into a wash
Delay Width 0 – 100 % 50 % Stereo width of the delay repeats
Delay Sync on/off off Lock the delay time to host tempo
Sync Note 1/64T … 1/8T 1/16 Delay time as a note division when Sync is on
Spec Freeze on/off off Capture and hold the current spectrum indefinitely
Stereo Width 0 – 200 % 100 % Master stereo width, mono to super-wide
Wander 0 – 100 % 0 % Depth of the slow random wander of the stereo width
Wander Rate 0 – 100 % 50 % Smoothness of the wander; higher drifts more slowly
Azimuth 0 – 100 % 0 % Depth of the slow random wander of the stereo position

The spectral delay delays each frequency bin independently — with Spread up, lows and highs repeat at different times, and Delay Tilt feeds back the top or bottom of the spectrum harder. Feedback is internally reduced as Tilt increases, so the loop stays bounded at every setting.

The Drawer: Life/Env Tab

The per-voice life modulators and the voice envelope.

Parameter Range Default Description
Orbit Depth 0 – 100 % 35 % Depth of the per-voice orbital wander across the stereo field
Orbit Rate 0.01 – 0.5 Hz (log) 0.1 Hz Speed of the orbital wander (100 s to 2 s per cycle)
Coupling 0 – 100 % 0 % How tightly the two orbit axes lock together
Growth −1 – +1 0 Orbit radius shrinks below zero, expands above
Voice Width 50 – 150 % 100 % Stereo width of each individual voice
Env Mode Standard / Growth Standard Standard attack, or Growth for a slow logistic rise
Growth Dur 1 – 60 s (log) 10 s Length of the Growth-mode rise
Stage 0 1 – 10000 ms (log) 2000 ms First envelope stage time
Stage 1 1 – 10000 ms (log) 4000 ms Second envelope stage time
Release 1 – 10000 ms (log) 8000 ms Release time after note off

Growth mode replaces the standard attack with a slow logistic swell — the note arrives rather than starting. It is the engine behind First Light, Approach Vector and Rising Dread.

Presets

Click Presets in the header to open the browser. Categories appear as tabs; double-click a preset to load it. Loading restores everything — every parameter, and any spectral states you authored by hand. Save writes the complete current state, authored slots included, into your user preset folder:

Factory Library

42 presets ship with the plugin, six in each of seven categories. Every one is rendered and verified during the build — each is proven to make sound, stay bounded, and be measurably distinct from all 41 others.

Textures

Preset Character
Vellum Thin, papery two-state morph with a soft upper tilt
Sea Glass Bright glass body, barely damped, over a sparse cloud
Slow Snow Sparse Blackman grains falling through a quiet cloud
Paper Sky Wide, downward-tilted wash with a slow partial drift
Rust Bloom Saturated, inharmonic and slowly mutating
Quiet Machine Dense short trapezoid grains, jittered into a hum

Pads

Preset Character
First Light Sine-stack pad that grows in over eight seconds
Long Exhale Standard envelope stretched to the ceiling: 8 s attack, 9 s release
Cathedral Moss Chamber body inside a large, soft Aether space
Warm Static Resonator bypassed — saturation and decorrelated grain only
Distant Choir Choral second state, pre-delayed and set well back
Blue Hour Dim, slowly orbiting pad with a wide grain bed

Drones

Preset Character
Deep Well Low, unlit drone with a twenty-second Aether tail
Stone Circle Very slow onset into a thirty-second room
Tectonic Heavy low tilt, inharmonic and driven hard
Iron Lung Body input AGC off — the resonator takes the full drive
Continuum Strings body, almost undamped, held indefinitely
Undertow Tidal Aether motion under a detuning cloud

Bells

Preset Character
Frost Bell Bell state, thin and cold, with a six-second cloud decay
Temple Rim Long struck rim, nearly harmonic, in a twelve-second room
Glass Carillon Parked on the glass state, struck and left to ring
Struck Ice Ice body, high resonance, almost no damping
Bronze Halo Metal plate, driven, ringing well past the note
Bell Garden Partials entering at staggered times, spread hard across the field

Choirs

Preset Character
Vowel Field The choir state held open, tilted down and blurred
Breath Chorus Breath into choir — the airiest pair in the library
Ghost Choir Atmosphere frozen: the grain bed stops moving and hangs
Aeolian Voices Wind-detuned voices, wide and never quite still
Whispered Mass Almost all grain: decorrelated, pitch-spread, barely pitched
Angelic Drift Shimmer octave and fifth folded back into the tail

Motion

Preset Character
Orbit Study External travel driving a fast spatial orbit
Tide Pool Three states, crawling between them while the space breathes
Wander Lamp Spline travel with four-second waypoints and a wandering image
Restless Tempo-synced spectral delay feeding a mutating cloud
Spiral Arms Coupled orbits sweeping the azimuth at the edge of the field
Slow Weather All four states in play, crossed at a geological rate

Cinematic

Preset Character
Approach Vector Growth envelope closing in over nine seconds
Event Horizon Aether frozen at maximum size — the note never lands
Signal Lost Spectral freeze over a saturated, inharmonic bed
Rising Dread Ten-second growth under a heavy downward tilt
Vast Frozen Aether at full width — scale without motion
Aftermath Exponential grains scattered late across a wide buffer

Performance Notes

Cross-Platform

Platform Formats Notes
Windows 10+ VST3 64-bit
macOS 12+ VST3, Audio Unit Universal (Intel + Apple Silicon)
Linux VST3 x86-64

State saved on any platform loads identically on the others.

Tips & Tricks

Seraphis is free and open-source software from Krate Audio, released under the MIT license.

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