Envelope follower

The envelope follower is a modulation source with an unusual quality: it listens to the signal running through the voice and turns what it hears into a moving value you can route anywhere. When the signal is loud, the follower’s output is high. When the signal is quiet, the output falls. Route that output to filter cutoff and the filter opens as the sound gets louder: the classic auto-wah, without any external signal required.

It lives in the Env Follow tab of the Modulators panel.

What it does

Every note in Aconite carries its own envelope follower. As the voice produces audio, the follower continuously tracks the signal’s amplitude and outputs a smooth, time-averaged level that rises and falls with the sound. That level is a modulation source like any other; you route it in the matrix or via a right-click on any knob.

The result is dynamics-as-modulation: the harder you play, the stronger the signal, and the further the follower pushes its destination. A soft note barely moves the target; a hard note drives it fully open.

The controls

Four controls shape how the follower tracks the signal:

• Attack: how quickly the follower responds to a rising signal. A short attack snaps to peaks immediately; a long attack smooths over transients and responds more to sustained levels.
• Release: how quickly the follower falls when the signal drops. A short release follows every dynamics fluctuation closely; a long release holds the high point longer, giving a slower, lazier swell.
• Sense: sets the input sensitivity, effectively scaling how loud a signal is needed to push the follower toward its maximum output. Turn it up to respond to quieter signals; turn it down to only react when the voice is driven hard.
• Detect: selects the detection mode, which governs how the follower reads the incoming signal. Different detection modes suit different source materials, from clean sine tones to harmonically rich, driven sounds.

Using the envelope follower

The follower becomes a source in the modulation matrix the moment you select Env Follow as a source. You can also right-click any knob and choose Add modulation → Env Follow to wire it directly.

Auto-wah: Route to Filter 1 Cutoff at a positive depth. The filter opens as you play harder and closes as the note decays. Adjust the Attack and Release to taste: a short attack with a medium release gives the classic “quack”, while a longer attack with a long release gives a slow swell.

Tremolo and gating: Route to the amp or waveshaper at a high depth. Playing harder drives the voice into a more distorted or louder space; playing softly retreats. With a short release, the follower can create subtle dynamic gating.

Modulation depth scaling: Route to an LFO’s rate or depth destination in the matrix. Now playing harder makes the LFO sweep faster or deeper: the modulation becomes velocity-responsive in a continuous, natural way.

Tip

The envelope follower responds to the synthesized signal inside the voice, not to external audio. Its behavior depends on the oscillator mix, filter settings, and anything in the chain. A heavily filtered voice produces a smoother, slower-changing follower output than a bright, transient-rich one; use this to your advantage when shaping the response.

Because the follower is per-voice, each note tracks its own dynamics independently. In a polyphonic chord, each voice’s follower responds to that voice’s own signal; they do not cross-talk. This makes the auto-wah effect feel natural across the whole keyboard.