Enchanting Instruments 116 - U-he Zebralette3 BETA2 Review Part 5

This is the final part of my introduction to the free software synth Zebralette3 BETA2.
In this article, I am going to talk about the MSEG (Multi-Stage Envelope Generator), which functions as a replacement for a traditional ADSR envelope, as well as the Modulation Matrix section.
These UI elements are located within the red box shown below.

MSEG (Multi-Stage Envelope Generator)

The MSEG in u-he's Zebralette3 functions similarly to a traditional envelope generator (ADSR) found in most synthesizers.
ADSR stands for “Attack”, “Decay”, “Sustain”, and “Release”, and it allows you to control levels over time, and it’s typically used for things like amplitude and filter cutoff.
However, unlike ADSR’s four fixed stages, the MSEG uses vector curves (see diagram) to define the envelope shape more freely. You’re not limited to just four stages. You can draw complex curves and even set them to loop.
The curve editing interface is nearly identical to that of the oscillator section, with the level of precision comparable to drawing software.

A major feature of the MSEG is not only the ability to draw curves freely, but it also has the ability to set up to seven different curves and morph between them.
Morphing refers to smoothly animating the transition between two different envelope shapes. This is a brand-new feature that’s not available in the original Zebralette and it’s rarely seen in other synthesizers. Because of this, many users might not immediately grasp how best to use it.
To help visualize its potential, the document provides a few usage examples. In one demo video, two MSEG curves morph when a note is triggered. The orange line shows the actual level, and you can observe it shifting between shapes to clearly highlight how this departs from the fixed behavior of a traditional ADSR.
Additionally, since these are vector-based envelopes, different morphing modes can be selected, allowing for highly flexible and expressive modulation.

Morphing MSEG with Velocity Sensitivity

Here’s a concrete example of using MSEG morphing to recreate the behavior of acoustic instruments where a stronger key press results in a faster attack, and a softer press produces a slower one.

In this setup, the user gradually increases key velocity. As a result, the sound morphs from something like a glass harp to a more percussive tone.
This kind of transformation is very difficult to achieve with a physical instrument, but MSEG morphing makes it possible in the digital realm.

Applying MSEG to Oscillator Morphing

This example sets up four basic waveforms in the oscillator and it uses the MSEG to switch between them every 16th note.

Using MSEG as a Sequencer

By modulating pitch with the MSEG, you can use it like a sequencer. In the following example, morphing is not used. This is a simple application.

Using MSEG as a Morphing Sequencer

Here, pitch is randomly fluctuated to avoid repetitive patterns, and create a more organic, evolving sequence.

MATRIX (Modulation Matrix)

Many parameters with knobs can be modulated, though not all. However, by using the MATRIX function, almost any knob can be modulated. Moreover, by layering two modulations, even higher values can be achieved. Additional options allow for settings like curve characteristics and scaling.
Zebralette3 supports up to 6 modulation slots, each capable of being applied to 2 destinations.
A downside is that it's not very visually intuitive, so you need a proper understanding of how it functions. Still, the MATRIX is essentially u-he’s standard modulation matrix, so if you're interested in other u-he products, this is a function worth knowing.

Modulating Pitch with Random Values

Here, modulation is applied using the random hold mode of an LFO.
If used as-is, it produces erratic, chaotic pitches.
To control this, the Quantize ("Q") option is combined, which constrains the random values to a musical scale.
To make the phrase feel more organic, the first modulation target is additionally applied to its own second-stage knob.

When heard, the result has a more musical, less chaotic quality than pure randomness.

Modulating Only the Attack of the ENV

As shown in the diagram below, we apply Velocity to the Attack parameter of the ENV (ADSR) to achieve a similar effect as the previous MSEG example.
When played softly, the sound rises more slowly; when played strongly, it rises more quickly.
The advantage here is that, unlike MSEG which requires fine-tuning, this setup is easy to configure.

Modulating Only the Attack of the ENV

As shown in the diagram below, I appllied Velocity to the Attack parameter of the ENV (ADSR) to achieve a similar effect as the previous MSEG example.
When played softly, the sound rises more slowly; when played strongly, it rises more quickly.
The advantage here is that, unlike MSEG which requires fine-tuning, this setup is easy to configure.

When you play the note C, the sounds within the major scale will play as shown below.
Some notes do not sound because of the timing of the trigger.
The waveform shape and speed cause various changes, but all remain within the scale.

The above is just a simple example, but MATRIX is a very deep function. In practical use, it tends to be used in more subtle ways.
Its true power shines in recreating analog-like sounds with complex behavior or in sound effect applications often used in movies.

Summary of Zebralette3 BETA2

Zebralette3 is the first synth to adopt vector-based synthesis and it has opened a new door in synthesis technology. What’s surprising is that it’s offered completely free.
Although it’s positioned as a promotional trial synth for the upcoming Zebra3, it actually provides more than enough features to be a fully functional synth.
Because it’s based on vector synthesis, it requires a somewhat different approach and some learning compared to traditional synths, but there’s no doubt it expands into an unknown realm.
If you’re interested in the future of synthesis, it’s definitely worth trying out.

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