Tube saturation Free

RSL One

One core. Warm or Tube. Yours to keep.

The same Warm and Tube saturation circuit as the RSL Dual Core Saturator, on a single core. Four knobs shape it, Auto Gain keeps your level, and LED meters show what the core sees. Free with an account, no license key.

Get it free in RSL Hub Download

Free. Version 0.2.0.

macOS: Audio Unit, VST3, AAX and Standalone. Windows: VST3 and Standalone.

The RSL One plugin: IN and OUT meters either side of a glowing valve, the WARM and TUBE switch, four knobs and INPUT, AUTO GAIN and OUTPUT

The same circuit as our flagship saturator, on one core, built to the same standard as the plugins we charge for. It costs you nothing.

A window on the circuit.

The window at the top shows the character you picked, a valve under Tube and a transformer under Warm, and it glows with the signal. The IN and OUT meters either side read -48 to 0 dBFS in 2 dB steps, with a peak hold.

IN reads what the saturation core actually sees. Set INPUT so it peaks around -12 to -6 dBFS and the core responds most musically.

The RSL One character window, a valve glowing copper

1Saturation core, from the Dual Core Saturator

2Characters: Warm and Tube

7Factory presets

±12dBOf input and output, with Auto Gain to link them

Top to bottom, in the order the signal flows

Pick a character, shape it with four knobs, then set the level going in and coming out. Scroll down and each part lights up in turn.

Step 1
Warm or Tube

Two characters from the RSL Dual Core Saturator. WARM is silky, transformer-flavoured glue with a body-leaning tone, at home on a mix bus. TUBE is vintage valve character with richer, brighter asymmetry. The window above shows a transformer or a valve, glowing with the signal.
Step 2
Wet, Grit & Sag, Density, Drive

WET blends the saturated signal with the dry one. GRIT & SAG shapes the tube's asymmetry, sag and softened top end (under Warm it becomes RICHNESS). DENSITY keeps transients punchy while harmonics bloom on sustained notes. DRIVE sets how hard the core is pushed.
Step 3
Input, Auto Gain, Output

INPUT sets how hard the signal hits the core, 12 dB either way; peaks around -12 to -6 dBFS on the IN meter respond most musically. Light AUTO GAIN and OUTPUT moves opposite INPUT, so gain staging never changes your level. The activity light glows brighter as the circuit works harder.

7 factory presets

Each one sets the character and the four saturation knobs and returns everything else to its default, so it sounds the same however you arrive at it. They load from the preset bar across the top.

Preset	Character	Settings (%)
Default	Tube	Drive 32, Grit & Sag 20, Wet 55, Density 30
Bus Glue	Warm	Drive 26, Richness 14, Wet 42, Density 38
Vocal Warmth	Warm	Drive 44, Richness 28, Wet 58, Density 24
Drum Crunch	Tube	Drive 62, Grit & Sag 46, Wet 72, Density 56
Valve Sheen	Tube	Drive 35, Grit & Sag 22, Wet 48, Density 18
Master Polish	Warm	Drive 18, Richness 10, Wet 30, Density 44
Full Melt	Tube	Drive 88, Grit & Sag 74, Wet 100, Density 66

Specifications

Characters: Warm and Tube, on one saturation core
Controls: Wet, Grit & Sag (Richness under Warm), Density, Drive, Input, Output, Auto Gain
macOS: Audio Unit, VST3, AAX (Pro Tools) and Standalone. Universal: Apple silicon and Intel
Windows: VST3 and Standalone
System: macOS 11 or later; Windows 10 or later (64-bit)
Latency: Small and fixed, reported to your DAW, which compensates for it. It stays the same in bypass
Meters: IN and OUT, left and right, -48 to 0 dBFS with peak hold
Presets: 7 factory presets, plus your own
Availability: Free with an account. Version 0.2.0. Install through RSL Hub or download directly