PRESSURE Control
The PRESSURE knob is the heart of the plugin. It simultaneously maps threshold, ratio, attack, release, and knee width using per-engine quadratic curves - one knob does the work of five parameters.
How It Works
PRESSURE uses a p² (quadratic) curve to map the 0-100% knob position to compression parameters. The quadratic scaling means the knob feels linear to your ears: small movements at the bottom make subtle changes, while the top of the range gets progressively more aggressive.
Each engine defines its own curve, so the same PRESSURE position produces different behavior depending on the selected mode. The tables below show exact values at P=0.0 (minimum), P=0.5 (midpoint), and P=1.0 (maximum).
AUTO Mode
When AUTO is enabled, attack and release are selected from engine-specific curves driven by PRESSURE rather than the manual timing controls. TONE shapes engine-specific sidechain behavior. DRUMS additionally uses program-dependent release.
TONE Interaction
The TONE knob tilts the sidechain detection frequency. On VCA, Drums, and VariMu engines, it controls a sidechain high-pass filter using a tone² curve:
VCA (MIX)
- SC HPF Range
- 20-300 Hz
- Notes
- tone² × 150 Hz, enabled when tone² > 0.01
FET (INST)
- SC HPF Range
- -
- Notes
- No sidechain HPF
Opto (VOCALS)
- SC HPF Range
- -
- Notes
- Controls emphasis (optical cell emphasis)
Dynamics (DRUMS)
- SC HPF Range
- 20-120 Hz
- Notes
- tone² × 120 Hz, protects kick drum
VariMu (MASTER)
- SC HPF Range
- 20-250 Hz
- Notes
- tone² × 120 Hz
| Engine | SC HPF Range | Notes |
|---|---|---|
| VCA (MIX) | 20-300 Hz | tone² × 150 Hz, enabled when tone² > 0.01 |
| FET (INST) | - | No sidechain HPF |
| Opto (VOCALS) | - | Controls emphasis (optical cell emphasis) |
| Dynamics (DRUMS) | 20-120 Hz | tone² × 120 Hz, protects kick drum |
| VariMu (MASTER) | 20-250 Hz | tone² × 120 Hz |
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VCA (MIX Mode)
Clean bus glue character
0%
- Threshold
- -14 dB
- Ratio
- 2.0:1
- Attack
- 30.0 ms
- Release
- 1200 ms
- Knee
- 12 dB
50%
- Threshold
- -21 dB
- Ratio
- 3.5:1
- Attack
- 22.75 ms
- Release
- 925 ms
- Knee
- 9.75 dB
100%
- Threshold
- -42 dB
- Ratio
- 8.0:1
- Attack
- 1.0 ms
- Release
- 100 ms
- Knee
- 3 dB
| PRESSURE | Threshold | Ratio | Attack | Release | Knee |
|---|---|---|---|---|---|
| 0% | -14 dB | 2.0:1 | 30.0 ms | 1200 ms | 12 dB |
| 50% | -21 dB | 3.5:1 | 22.75 ms | 925 ms | 9.75 dB |
| 100% | -42 dB | 8.0:1 | 1.0 ms | 100 ms | 3 dB |
Swipe sideways to compare
Knee width scales inversely with ratio, which keeps low settings broad and high settings firmer.
FET (INST Mode)
Fast, assertive character
0%
- Threshold
- +22 dB
- Ratio
- 4.0:1
- Attack
- 800 μs
- Release
- 50 ms
- Knee
- 6 dB
50%
- Threshold
- +7.75 dB
- Ratio
- 4.0:1
- Attack
- 605 μs
- Release
- 150 ms
- Knee
- 6 dB
100%
- Threshold
- -35 dB
- Ratio
- 21.0:1
- Attack
- 20 μs
- Release
- 50 ms
- Knee
- 6 dB
| PRESSURE | Threshold | Ratio | Attack | Release | Knee |
|---|---|---|---|---|---|
| 0% | +22 dB | 4.0:1 | 800 μs | 50 ms | 6 dB |
| 50% | +7.75 dB | 4.0:1 | 605 μs | 150 ms | 6 dB |
| 100% | -35 dB | 21.0:1 | 20 μs | 50 ms | 6 dB |
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Ratio steps at P=60%→8:1, P=80%→12:1, P=92%→20:1, P=97%→extreme ratio mode (21:1). Release follows a V-shaped curve peaking at P=50%.
Opto (VOCALS Mode)
Smooth optical character
0%
- Threshold
- 0 dB
- Ratio
- 2.0:1
- Peak Reduction
- 0
- Mode
- Compress
50%
- Threshold
- -18 dB
- Ratio
- 4.5:1
- Peak Reduction
- 15
- Mode
- Compress
100%
- Threshold
- -72 dB
- Ratio
- 12.0:1
- Peak Reduction
- 60
- Mode
- Compress/Limit
| PRESSURE | Threshold | Ratio | Peak Reduction | Mode |
|---|---|---|---|---|
| 0% | 0 dB | 2.0:1 | 0 | Compress |
| 50% | -18 dB | 4.5:1 | 15 | Compress |
| 100% | -72 dB | 12.0:1 | 60 | Compress/Limit |
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Ratio is continuously variable (not stepped) and increases with signal level. No sidechain HPF; TONE controls emphasis instead.
Dynamics (DRUMS Mode)
Direct, hard-knee character
0%
- Threshold
- -8 dB
- Ratio
- 2.0:1
- Attack
- 30.0 ms
- Release
- 300 ms
- Knee
- 0 dB (hard)
50%
- Threshold
- -14 dB
- Ratio
- 3.5:1
- Attack
- 23.25 ms
- Release
- 250 ms
- Knee
- 0 dB (hard)
100%
- Threshold
- -32 dB
- Ratio
- 8.0:1
- Attack
- 3.0 ms
- Release
- 100 ms
- Knee
- 0 dB (hard)
| PRESSURE | Threshold | Ratio | Attack | Release | Knee |
|---|---|---|---|---|---|
| 0% | -8 dB | 2.0:1 | 30.0 ms | 300 ms | 0 dB (hard) |
| 50% | -14 dB | 3.5:1 | 23.25 ms | 250 ms | 0 dB (hard) |
| 100% | -32 dB | 8.0:1 | 3.0 ms | 100 ms | 0 dB (hard) |
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Hard knee always enforced. Slightly slower attack than VCA preserves drum transients.
VariMu (MASTER Mode)
Wide-knee mastering character
0%
- Threshold
- -24 dB
- Ratio
- 2.0:1
- Attack
- 0.4 ms
- Release
- 5000 ms
- Knee
- 15 dB
50%
- Threshold
- -29 dB
- Ratio
- 3.5:1
- Attack
- 0.35 ms
- Release
- 3825 ms
- Knee
- 13.25 dB
100%
- Threshold
- -44 dB
- Ratio
- 8.0:1
- Attack
- 0.2 ms
- Release
- 300 ms
- Knee
- 8 dB
| PRESSURE | Threshold | Ratio | Attack | Release | Knee |
|---|---|---|---|---|---|
| 0% | -24 dB | 2.0:1 | 0.4 ms | 5000 ms | 15 dB |
| 50% | -29 dB | 3.5:1 | 0.35 ms | 3825 ms | 13.25 dB |
| 100% | -44 dB | 8.0:1 | 0.2 ms | 300 ms | 8 dB |
Swipe sideways to compare
Attack is clamped to 0.2-30 ms and release to 300-5000 ms for broad mastering-style control. Knee stays wide (10-24 dB). Tube warmth: even harmonics at 0.23 + tone × 0.32. `outputTiltAmount_` HF shelf removed in v1.2.
Preset-Specific Curves
When a factory preset is active, PRESSURE uses a signed-p²mapping centered at P=0.5 (the preset's home position). Each preset defines its own home parameters and scaling ranges, so the knob always feels musical relative to that preset's sweet spot.
centered = pressure - 0.5
t = sign(centered) × centered² × 4
P=0.0 → t=-1.0 (gentlest)
P=0.5 → t= 0.0 (home - the sweet spot)
P=1.0 → t=+1.0 (most aggressive)
param = home + t × range
See Presets for the full list of 34 factory presets with their home parameters.