XILS-lab polyKB III v3.6 [WiN-MAC]

• Publisher: XILS-lab
• Product: polyKB III
• Version: 3.6.4
• Format: VST2, VST3, AAX, AU
• Source: xils-lab.com/products/polykb-iii-&-ii-p-159.html

PolyKB III stands out as one of the most versatile analog-modeled polysynths on the market. Its continuous morphing oscillators, dual 0 df filters, per-voice modulation engines, and supersized sequencer deliver a unique palette of sounds. While its depth may intimidate beginners, the sonic rewards are unparalleled.

The Morphing Analog Beast: A Sound Designer’s Deep Dive into XILS-Lab PolyKB III

In the world of vintage synthesizers, there are legends, and then there are the ultra-rare unicorns. The RSF PolyKobol 2, with its groundbreaking continuous morphing oscillators, is one of those unicorns. XILS-Lab has not only resurrected this spirit in the PolyKB III but has expanded it into a modern synthesis powerhouse that goes far beyond simple emulation.

As a sound designer who lives for deep, evolving textures and complex modulation, I couldn’t wait to get my hands on it. My goal here is to give you my honest, first-hand account and provide a guide to unlocking its immense creative potential.

Key Takeaway

XILS-Lab’s PolyKB III is a uniquely powerful and expressive analog-modeled polysynth that brilliantly expands on the legendary RSF PolyKobol 2. Its three continuous morphing oscillators, dual zero-delay feedback filters, and groundbreaking per-voice modulation capabilities make it an indispensable tool for sound designers and producers seeking rich, evolving, and deeply organic textures.

What Sets It Apart: The Core Sound Engine

The heart of the PolyKB III’s character comes from two key areas that set it apart from other analog emulations.

• Continuous Morphing Oscillators: Instead of being limited to fixed wave shapes, each of the three oscillators allows you to fluidly sweep from triangle through saw and into pulse width modulation. This continuous morphing, combined with hard sync and the ability to use oscillators as audio-rate LFOs, creates a palette of harmonically rich and constantly shifting timbres that is incredibly inspiring.
• Dual “0 df” Multimode Filters: The proprietary “zero-delay feedback” filters are the soul of the synth’s warmth. They reproduce the creamy, musical behavior of vintage analog gear with stunning accuracy, capable of self-oscillation in low-pass, band-pass, and high-pass modes. The pre/post drive controls allow you to dial in everything from subtle warmth to aggressive saturation.

Daniel Holden’s Guide: Unlocking the Creative Potential

The PolyKB III is an incredibly deep synth. Here are some practical tips for harnessing its most powerful and unique features.

1. Mastering Per-Voice Modulation (Voice XY & Space XY)

This is where the PolyKB III truly becomes a living, breathing instrument.

• The Voice XY Pad is your secret to “humanization” on an unprecedented level. It allows you to assign up to four parameters (like filter cutoff, envelope decay, or oscillator pitch) that will have slightly different values for each note you play. I use this to create subtle, non-repeating variations in my pads and leads, making them sound far more organic and analog than a standard unison spread.
• The Space XY Pad is your ticket to massive stereo width. It lets you place each individual voice in a 3D stereo field. You can create a wide, stable stereo image or introduce chaotic motion for pads that swirl and evolve around the listener. This feature alone can eliminate the need for external stereo widening effects.

2. The Sequencer as a Super Modulator

The massive 128-step, four-track polyphonic sequencer is not just for notes; it’s a powerhouse modulation source. Here’s a quick workflow:

1. Create a simple, sustained pad sound.
2. Go to the sequencer and, instead of programming notes, create a sequence of varying step values.
3. In one of the User Modulation Matrixes, assign a sequencer track as the Source and the filter cutoff as the Destination.
4. Now, the sequence is creating a complex, rhythmic filter pattern, transforming your static pad into a dynamic, gated texture.

3. Recipe for Evolving Pads

The PolyKB III excels at creating huge, evolving soundscapes. Here’s my go-to recipe:

1. Start with two morphing oscillators, setting them to slightly different initial waveforms and detuning them slightly.
2. Use a slow, free-running LFO to gently modulate the waveform knob of Oscillator 1, creating a constant, subtle timbral shift.
3. Now for the magic: go to the Voice XY pad. Assign the fine-tuning of Oscillator 2 to the X-axis and the Filter 1 cutoff to the Y-axis. Set the amount to be very subtle.
4. As you play a chord, each note will now have a slightly different pitch and filter setting, creating a rich, complex, and beautifully unstable analog-style pad that never repeats in exactly the same way.

My Honest Look: Pros and Cons

Pros	Cons
Unmatched sonic richness from the continuous morphing oscillators.	A steep learning curve, especially for novice synth users.
Deep per-voice modulation via the Voice XY and Space XY pads for organic textures.	The GUI is densely packed with controls and may feel overwhelming at first.
Huge modulation possibilities with 35+ hardwired routings and four user matrixes.	It’s a pure synthesizer; there are no built-in granular or wavetable engines for sample-based sound design.
The supersized polyphonic sequencer is a powerhouse for both melody and modulation.	Complex patches with high voice counts can be moderately CPU-intensive.

My Recommendation: Who Should Buy PolyKB III?

This is a deep, professional instrument for those who are serious about sound design. I would highly recommend it for:

• Sound Designers who want to create complex, evolving textures with unparalleled per-voice control.
• Electronic Music Producers who need a source of rich, organic, and powerful analog-modeled sounds.
• Analog Synth Aficionados who crave a faithful and expanded emulation of the legendary PolyKobol 2.
• Composers and Ambient Artists who can leverage the incredible stereo-scene control and step modulation for immersive soundscapes.

Frequently Asked Questions (FAQ)

Final Verdict

XILS-Lab’s PolyKB III is a true masterpiece of virtual analog synthesis. It stands out as one of the most versatile and sonically rich polysynths on the market today. Its continuous morphing oscillators, dual “0 df” filters, and, most importantly, its groundbreaking per-voice modulation engines deliver a unique and inspiring palette of sounds. While its depth may intimidate beginners, the sonic rewards for those willing to explore its capabilities are simply unparalleled. Highly recommended.