A non-linear saturation plug-in for professional audio engineers, offering precision control over waveform shaping and harmonic distortion. It emulates an overdriven amplifier with separate controls for low-level details, peak saturation, and even harmonics.
Purpose and Core Concept
RA II is a non-linear plug-in designed to manipulate audio dynamics and tone through controlled waveform compression. It functions like an overdriven amplifier but lets you choose which part of the signal gets processed, similar to applying a curve in photo editing software. The controls are grouped into low-level, peak, even harmonics, and drive sections.
This plug-in is suited for engineers who want to add detail, thickness, or saturation without conventional compression settings. It introduces third harmonic distortion when low-level or peak controls are used, while the even harmonic group can create octave-based coloration. The interactive controls influence each other, and a graphic display helps predict the effect on the waveform.
Key Capabilities: Low Level and Peak Controls
The LOW LEVEL control is central, boosting quiet audio content to reveal detail, akin to upward compression but without attack or release times. It adds third harmonic distortion and can amplify the effect of other plug-ins downstream. This control works on any signal and is especially noticeable on vocals, changing their dynamics.
The PEAK controls function like an adjustable soft clipper, rounding off peaks while leaving low-level content intact. A separate HARDNESS control shapes the saturation curve: soft limits peaks near -3 dBFS, while hard reduces them to about -10 dBFS. Applying this to a snare drum can prevent occasional overs and make the track appear louder without actual peak increase.
Understanding Even Harmonics and Drive
The even harmonic group includes TOP and BOTTOM controls that round off the top or bottom of the waveform. This produces even-order distortion, which can be subtle—some may not notice 50% second harmonic—but it changes the perceived feel and can thicken the sound. Used together, they can cancel even harmonics, leaving only third harmonic.
A DRIVE control before the processing adjusts input gain by ±6 dB, making the saturation more or less aggressive based on level. There is also an output TRIM for matching gain, also ±6 dB. Clipping the input or output lights a clip indicator, but the tonal shaping controls themselves do not clip. The drive is unity gain by default, but boosting high-level signals can cause clipping.
Workflow and Practical Applications
To use RA II effectively, start with LOW LEVEL to add detail to a vocal or bass, then adjust PEAK to tame transients on drums or mix bus. The HARDNESS control lets you fine-tune the saturation curve for a softer or more aggressive limit. Experiment with even harmonics on acoustic guitar, bass, or kick to add thickness.
Because controls are interactive, tweaking one affects the others, so listen and watch the graphic display. Use DRIVE to match input levels for consistent behavior across tracks. The plug-in is ideal for lifting quiet passages, controlling peaks, and adding harmonic coloration in mixing or mastering, but requires monitoring to avoid unintended clipping.
Key features
- Non-linear waveform compression with low-level and peak controls
- Low Level control adds third harmonic distortion and enhances detail
- Peak controls with adjustable hardness for soft clip behavior
- Even harmonic controls for top and bottom waveform rounding
- Drive and trim controls with ±6 dB range for gain matching
- Graphic display of distortion curve for visual feedback
- Clip indicator for input/output clipping
Best for
RA II is best for professional audio engineers mixing or mastering who need precise control over saturation and detail. Use it on vocals to bring up subtle nuances, on drums to soften transients, or on instruments like bass and acoustic guitar to add thickness and harmonic interest.