How Dual Core Saturation Works | Renegade Sound Labs

Two cores,
one crossover,
seven behaviors

Put one saturator across a full mix and the loudest band decides what everyone else gets: the kick smears before the top end gets exciting. This plugin splits the signal where you choose and drives each side on its own core. What follows is the whole circuit, in the order the audio meets it.

2saturation cores

7modeled characters

8×oversampling

−3 dBtrue-peak ceiling

Ten stages, in the order the audio meets them

The short version: two saturation cores do the work, and everything after them is the output stage that carries the result out of the plugin.

The marked stages run oversampled, up to 8×, which is where aliasing would otherwise be made. Everything after the transformers runs at the session rate.

Core 1, before the split

A restrained Warm stage that divides the spectrum at a single crossover and lets the low and high regions take independent amounts of pre-saturation. It prepares the material before anything parallel happens.

Core 2, the parallel engine

Mid/side band isolation, the selected character, residual extraction, then Density, Wet, Tilt and Focus. Two blue handles set the band it works on, and content outside that range is excluded rather than attenuated.

It adds the difference, not the distortion

The part that is easy to miss: Core 2 never replaces your band. It isolates one, processes it, subtracts the original, and blends only what is left.

Step 1 · Isolate

The band between the two handles, taken out of the mid and side signal on its own.

Step 2 · Process

The character works on that band alone. The original shape is still there underneath it.

Step 3 · Subtract and blend

Subtract the original band and this is what is left: the new harmonic and level-moving content, and nothing else. Wet sets how much of it joins the dry signal.

That is why density can go up while the original transient path stays intact, and it is why a mix takes a lot of this before it starts sounding processed. You are hearing your own signal with something added underneath it rather than a copy of it that has been redrawn.

Mix law: what happens to the dry path as you raise Wet
Mix law	Dry path	Core 2 residual
Push	Remains at unity.	Layers on top as Wet rises.
Match	Fades as the processed contribution rises.	Crossfades toward the processed result.

Mix law: what happens to the dry path as you raise Wet

Mix law

Dry path

Core 2 residual

Push

Remains at unity.

Layers on top as Wet rises.

Match

Fades as the processed contribution rises.

Crossfades toward the processed result.

03 Seven characters

What each one is actually modeling

Drive sets the musical operating amount. Depth changes how far the model is allowed to travel, so its meaning changes with the character. On three of them, passing a threshold opens behavior that was not there at lower settings.

Symmetric, odd-weighted

Warm

The one to reach for when you want cohesion rather than an effect anyone can name.

A smooth, symmetric saturating response weighted toward odd harmonics. Depth adds richness without turning the stage into a hard clipper, which is why the same circuit sits under everything else as the pre-split stage.

Drive: Warmth and glow
Depth: Harmonic richness
Best for: Bus glue, vocals, broad cohesion

Asymmetric valve

Tube

Even-order color that gets less clinical the harder you push it.

An asymmetric valve response with additional even-order character. As Depth rises the circuit develops stronger asymmetry, vintage sag and progressive high-frequency softening, the way a valve stage does when it is asked to work.

Drive: Tube intensity
Depth: Grit, sag and softened top
Best for: Vocals, bass, drums and buses that should feel less clinical

Rounded to hard

Clip

Drive walks the signal up to the edge. Depth decides how firm that edge is.

A continuously variable rounded-to-hard clipping stage. The true-peak Ceiling is a separate stage further down the chain, so shaping the transient and protecting the output never have to fight each other.

Drive: Clip intensity
Depth: Smooth to hard edge
Best for: Peak shape, aggressive drums, loudness preparation

Magnetic transport

Tape

Stable premium tape, not damaged lo-fi tape.

Models stateful oxide magnetization, restrained hysteresis, a head bump, program-dependent compression, level-dependent treble loss and subtle wow and flutter. 30 IPS emphasizes the classic warm low-end head bump; 60 IPS moves that emphasis up toward the low mids.

Drive: Magnetization amount
Depth: Opens the soft ceiling
Best for: Density and glue with movement

Tape opens in tiers

DensityDrive 0 to 100%Low-level thickening and mild even harmonics.
MagnetDrive around 40%Hysteresis, head bump and greater harmonic density.
LimitDepth around 18%Soft ceiling, program compression and HF saturation.

Living ferrofluid core

Ferro

Sustained sound changes what the next transient runs into.

Ferro carries magnetic memory. It tracks per-core magnetization, a shared field, thermal conditioning and polarity lean, and mid/side activity can influence the shared chamber. It is not a curve. It is a system with a history.

Drive: Iron density
Depth: Opens bloom, then chaos
Best for: Weight with movement, low-mid character

Ferro opens in tiers

IronDrive 0 to 100%Low-mid density and transformer weight.
BloomDrive around 60%Harmonic bloom, softened transients, dynamic HF rounding.
ChaosDepth around 20%Intermodulation, transient-dependent compression, drifting phase.

Liquid gain cell

Ionic

Not a waveform shaper. It moves level, then blends the difference.

Below its reference region Ionic can lift; above it, it restrains. Mid and side share one virtual ion cloud, which protects image stability, and transients can pass before the slower cell completes its reaction. Its harmonic display therefore shows level movement rather than new harmonic orders.

Drive: Primary leveling action
Depth: Viscous memory, longer hold, swelling recovery
Best for: Density and control without obvious distortion

The RSL Dual Core Saturator with the VO2 character selected.

Phase-transition distortion

VO2

A wafer that stays partly metallic after the energy that triggered it has gone.

Models a vanadium-dioxide wafer transitioning from insulating sapphire to metallic domains. The transition is abrupt and hysteretic. This is the one to reach for when the record wants something that sounds broken on purpose, and the first one to back off when it does not.

Drive: Approach to the threshold
Depth: Opens instability
Best for: Aggressive color and deliberate instability

VO2 opens in tiers

ColdDrive 0 to 100%Crystalline grit approaching the phase threshold.
MetalDrive around 80%Abrupt clip and octave-up components.
ChaosDepth around 13%Sputtering, period-doubled subharmonics, instability.

Tape and Ferro are stateful. Played from the same spot twice they will not produce exactly the same response, because recent program history is part of the sound.

Instruments, not decoration

Two of the readouts are measurements you can act on rather than animation: where your input sits, and how much the character is actually adding.

Core 2 reaches full scaling between −12 and −6 dBFS, opens progressively below it, and deliberately backs off above it. Set the input by eye and the readout tells you which side of the window you are on.

Injection heat is measured

The color on the analyzer is measured residual energy from the active character, not an estimate from knob positions. Blue is light, gold is moderate, orange is strong. The six-band harmonic meter then shows how those regions move over time.

Residual solo and gain match

Residual solo isolates the Core 2 difference signal on its own, with the output transformers and Console deliberately excluded, so what you hear is the dual-core contribution and nothing downstream of it. Gain match then levels the comparison, which is the only way an A/B tells you anything true.