Saturator with a transient-triggered Collapse stage
Version
1.0.0
Platform
Windows
Formats
VST3 and CLAP
User Guide
brucejames.studio
Slursh
Contents
01
01Overview and the core idea02
02How it works03
03Installation and authorization04
04Interface tour05
05Parameter reference06
06The Collapse stage in depth08
07Workflows09
08FAQ and troubleshooting10
09License and contact11
01 · Overview
Rounded saturation, then a duck that locks to the transients
Slursh runs two engines in series. Slush is a soft-clip saturator that rounds the waveform toward a sine as you push it, for thick harmonic colour rather than hard digital clipping. Collapse tracks the low-frequency energy of the signal and, when it crosses a threshold, ducks the low and high bands independently, producing a rhythmic pump that follows whatever you feed it.
A threshold network keeps quiet detail clean while louder material saturates, and the dry path stays phase-clean, so at 0% wet the plugin nulls to silence and the Null button leaves only what Slursh is adding.
In one line
Saturate with Slush, duck the low and high bands on transients with Collapse, and audition the difference with Null.
02 · Concept
How it works
02
Two stages in series explain almost everything Slursh does: the Slush saturator, the Collapse ducker, and a phase-clean dry path that ties them together.
In
Input
→
Stage 1
Slush
tanh soft-clip with a threshold / floor / knee blend back to dry.
→
Stage 2
Collapse
transient-triggered ducking of the low and high bands around a crossover.
→
Out
Output
Signal flow. Input gain feeds the Slush saturator, whose output passes into the Collapse ducker before the output stage. Dry/Wet blends the whole chain against the clean input.
01Slush rounds the waveform
Slush pushes the signal into a tanh soft-clip. As Drive rises the waveform is rounded further toward a sine, giving thick, even saturation instead of the brittle edges of hard clipping. A threshold network blends the dry signal back in below a level you set, so quiet passages stay clean while louder material is driven into colour. Floor sets the minimum saturation allowed under that threshold, and Knee sets how soft the transition into saturation is.
02Collapse ducks on transients
Collapse follows the low-frequency energy of the signal. When that energy crosses the Collapse Threshold, the effect engages and ducks two bands split at a sweepable crossover: the low band and the high band, each with its own duck depth, attack, and release. The result is a rhythmic pumping and de-pumping that locks to the transients of the source. As the low band collapses it can also be driven toward a squared-off fundamental with Squarify.
03The dry path stays phase-clean
Slursh keeps the unprocessed signal phase-aligned with the processed one. At 0% Dry/Wet the two cancel to silence, which means parallel blends stay tight with no comb filtering. The Null button subtracts the dry signal from the output so you hear only the saturation and collapse movement Slursh is adding.
What triggers the duck
Collapse is driven by low-frequency energy, not full-band level, so kicks and low transients set the rhythm of the pump. Lowering the Collapse Threshold keeps the duck engaged on steadier material.
03 · Setup
Installation and authorization
03
Slursh runs on Windows in VST3 and CLAP hosts. Installation places the plugin in the standard system folders that compatible DAWs scan automatically.
Install
Close your DAW before installing so it rescans plugins on the next launch.
Run the installer and accept the license agreement. The VST3 build installs to C:\Program Files\Common Files\VST3 and the CLAP build to C:\Program Files\Common Files\CLAP.
Launch your DAW and let it rescan. If Slursh does not appear, trigger a manual rescan or add the folders above to your plugin paths.
Insert Slursh on a channel or bus. It works on individual elements and on submixes, so it usually lives on a track or a bus rather than the master.
Authorization
When prompted, enter the license key from your purchase confirmation. Once accepted, your license is written to %APPDATA%\Slursh\license.json and applies to every instance on that machine. When unlicensed, Purchase and Authorize pills appear in the top bar. If you rebuild or replace a system drive you will need to reactivate, since activations are not part of a normal file backup; this is expected.
Updates
Slursh can check for new versions from the Settings panel. When a newer build is available, an Update Available badge appears in the top bar. Updates install over the existing version; your saved presets and project state are preserved.
Display scaling
The window is 760 by 400 pixels and scales to 100, 150, or 200 percent. Open Settings by clicking the round logo mark at the top right, then choose the UI size that suits your display and save it as part of your default state.
04 · Reference
Interface tour
04
A top bar with the wordmark and utility buttons, two metering flanks, the Slush and Global knobs and envelope display up top, and the Collapse row along the bottom.
1234567891011
1Wordmark and subtitleThe slursh mark with the SATURATOR · COLLAPSE label, plus license state.
2Bypass · NullHard bypass, and Null to hear only what Slursh adds.
3Logo mark · SettingsOpens UI size, update check, and support email.
4Drive meterSaturation amount, +6 / 0 / -12 / -30, green to amber to red.
5Slush sectionDrive, Thresh, Floor, Knee — the saturator controls.
6Global sectionInput, Dry/Wet, Output.
7Envelope displayHI (pink) and LO (teal) attack and release shapes with live travelling balls.
8Engaged LEDLights teal to pink with collapse activity.
9Collapse meterHow far the collapse has engaged, FULL / ½ / ¼ / 0, teal to pink.
11Value readoutShows a knob's current value while you drag it.
05 · Reference
Parameter reference
05
Every control, grouped as it appears in the plugin. Defaults follow the in-app values.
Global
Control
Range · Default
Behavior
Input
-24 to +12 dB · 0
Input gain applied before saturation. Drives how hard the signal hits the Slush stage.
Dry / Wet
0 to 100% · 100%
Blend between the dry input and the processed signal. The dry path is phase-clean, so 0% nulls to silence.
Output
-24 to +12 dB · 0
Output gain applied after processing.
Slush · saturation
Control
Range · Default
Behavior
Drive
1 to 10 · 1
How hard the signal is pushed into the tanh saturator. Higher values round the waveform further toward a sine.
Threshold
low to high · ~0.3
Level below which the dry signal is blended back in, so quiet detail stays clean while louder material saturates.
Floor
0 to 1 · 0
Minimum amount of saturation blended in below the threshold. 0 is fully clean under threshold.
Knee
0 to 1 · 0.5
Softness of the transition into saturation. 0 is hard, 1 is gentle.
Reading the Drive meter
The left meter shows the amount of saturation being applied, not just output level. Watch it fill from green into amber and red to judge how hard Slush is working, then use Output to set the level it leaves at.
05 · Reference
Parameter reference
05
Collapse · transient-triggered ducking
Control
Range · Default
Behavior
Amount
0 to 100% · 100%
Overall depth of the collapse effect. 0 is off.
Xover
100 to 1000 Hz · 600
Crossover frequency splitting the duck into a low and a high band.
Threshold
0 to 1 · 0.3
Low-energy level at which the collapse engages.
Lo Duck
0 to 48 dB · 6
How far the low band drops when engaged.
Hi Duck
0 to 48 dB · 12
How far the high band drops when engaged.
Lo Atk
1 to 500 ms · 10
Attack time of the low-band gate.
Hi Atk
1 to 500 ms · 5
Attack time of the high-band gate.
Lo Rel
10 to 2000 ms · 120
Release time of the low-band gate.
Hi Rel
10 to 2000 ms · 80
Release time of the high-band gate.
Squarify
0 to 1 · 1
How much the low band is driven toward a squared-off fundamental as the collapse engages.
Utility
Control
State
Behavior
Bypass
on · off
Hard bypass. Processing halts and the input passes through unchanged.
Null
on · off
Subtracts the dry signal from the output so you hear only what Slursh is adding. Useful for auditing the effect in isolation.
Metering
Readout
Shows
Behavior
Drive
left flank
Saturation amount — how much the waveform is being bent by the Slush stage. Fills bottom-up, green to amber to red.
Collapse
right flank
How far the Collapse stage has engaged. Fills top-down, teal to pink.
Envelope
upper right
Live attack and release position for the HI and LO bands, drawn as travelling balls.
Engaged LED
collapse header
Lights teal to pink with collapse activity.
06 · Deep dive
The Collapse stage in depth
06
Collapse is two independent gates sharing one trigger. Reading the envelope display makes the rest of the controls intuitive.
HI
LO
Attack
Hold
Release
Schematic of the envelope display. Each band ducks down on attack when the collapse engages, holds while the trigger persists, then releases back up. The travelling balls show where each band currently sits. The HI band typically uses a faster attack and shorter release than the LO band.
The trigger and the two bands
The Collapse Threshold listens to low-frequency energy. When that energy crosses it, both gates fire. Xover decides where the signal is split: everything below it is the low band, everything above is the high band. Each band then has its own depth — Lo Duck and Hi Duck — so you can pump the lows hard while barely touching the highs, or the reverse.
Shaping the movement
Attack sets how fast a band drops once triggered. Short Hi Atk values give a sharp, clicky duck; longer values soften the onset. The defaults attack the high band faster than the low band.
Release sets how long a band takes to return after the trigger falls away. Long releases give a slow breathing pump; short ones give a tight, rhythmic chop. Watch the travelling balls to dial the feel by eye.
Squarify on the low band
As the low band collapses, Squarify drives it toward a squared-off fundamental. At higher settings the ducked lows take on a harder, fundamental-heavy character rather than simply dropping in level, which is useful for carving space while adding weight under a transient.
When to reach for it
Pair Squarify with a higher Lo Duck and a crossover set around the bass and low-mid split to reshape a bass line as the transients hit.
07 · Practice
Workflows
07
Starting points, not rules. Adjust to the material and watch the meters and envelope display.
01Glue and thickness on a drum bus
Insert on the drum bus and raise Drive for rounded saturation. Set Collapse Amount around 50% and lower the Collapse Threshold until the kick and snare transients trigger the duck. A low Xover, roughly 150 to 300 Hz, lets the low band pump with the kick while the highs stay present.
Drive upAmount ~50%Xover 150–300 HzThreshold down to taste
02Rhythmic pump on a sustained source
On a held pad or synth, lower the Collapse Threshold so steady energy keeps the duck engaged. Shape the movement with Lo and Hi Release: longer releases give a slow breathing pump, shorter ones a tighter chop. Use the travelling balls in the envelope display to dial the feel.
Threshold lowLo/Hi Rel long = breatheLo/Hi Rel short = chop
03Parallel saturation
Pull Dry/Wet below 100% to blend the saturated and collapsed signal under the dry. Because the dry path is phase-clean, the blend stays tight with no comb filtering, so you can drive Slush hard and dial in only as much as the part needs.
Dry/Wet below 100%Drive hardBlend to taste
04Bass control with the low band
Raise Lo Duck and Squarify, and set Xover around the bass and low-mid split. As transients hit, the low band ducks and squares off, carving space and adding a fundamental-heavy character under the hits.
Lo Duck upSquarify upXover bass/low-mid
05Auditing what you are adding
Enable Null and solo the track to hear only the delta — the saturation plus the collapse movement — in isolation. It is the quickest way to confirm the effect is doing what you intend before committing it to the mix.
Null onSolo track
08 · Support
FAQ and troubleshooting
08
Slursh does not appear in my DAW.
Confirm the DAW has rescanned plugins after installation, and that the VST3 and CLAP system folders are in its scan paths. Some hosts require a manual rescan or a restart.
The Collapse stage does not seem to do anything.
Collapse is triggered by low-frequency energy crossing its Threshold. If nothing is happening, lower the Collapse Threshold, raise Amount above zero, and check that Lo Duck or Hi Duck is set above zero. The Engaged LED and the right-hand Collapse meter confirm when it is firing.
The pump sounds clicky or too abrupt.
Lengthen the attack times, especially Hi Atk, to soften the onset, and raise the release times so the bands return more gradually. Watch the travelling balls in the envelope display to see the shape you are dialing.
The saturation is distorting quiet passages I wanted to keep clean.
Raise the Slush Threshold so more of the dry signal is blended back in below it, and keep Floor low so there is little or no saturation under the threshold. Increasing Knee softens the transition into saturation.
The output is much louder or quieter after processing.
Heavy Drive adds level and the duck removes it, so net level shifts. Use the Output knob to compensate, and read the Drive meter to judge how hard the saturator is working rather than going by loudness alone.
What does Null actually do?
It subtracts the dry signal from the output, leaving only the difference Slursh is introducing — the saturation and the collapse movement. Solo the track with it engaged to audition that delta in isolation. Because the dry path is phase-clean, the subtraction is exact.
How do I change the window size?
Click the round logo mark at the top right to open Settings, then choose 100, 150, or 200 percent. The same panel holds the update check and the support email.
Do my presets survive an update?
Yes. Updates install over the existing version and preserve saved presets and project state.
09 · Legal
License and contact
09
License
Use of Slursh is governed by the end user license agreement included with the distribution as license.txt. Please refer to that file for the full terms. Your purchase authorizes installation under the conditions described there. After activation, your license is stored at %APPDATA%\Slursh\license.json.
Included files
The distribution archive contains the installer along with readme.txt for installation notes, changelog.txt for version history, and license.txt for the agreement. The readme is the canonical source for installation details.
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