The PolyKB III is XILS-Lab's software interpretation of the RSF PolyKobol 2, a rare and expensive hardware synth prized for its morphing oscillator architecture. Unlike typical analog modeling synths that switch between discrete waveform types, the PolyKB III generates oscillators that smoothly transition across the entire morphing space, yielding hundreds of distinct timbral variations. This approach produces genuinely novel waveforms rather than recreating fixed vintage designs, a meaningful distinction for sound design work.
The core signal path includes dual multimode filters employing XILS-Lab's proprietary 0DF (Zero Delay Feedback) technology, which handles self-resonance cleanly across all modes without the instability common in naive filter implementations. Three modulation envelopes with time multiplication and loop functions, paired with two sophisticated LFOs, provide ample modulation sources for evolving, complex timbres.
Where the PolyKB III distinguishes itself is in per-voice modulation. The Voice XY module allows real-time 2D control of up to four parameters on a per-note basis, enabling individual voices within a chord to receive subtle or dramatic variations. The Space XY module extends this concept to stereo placement and movement, positioning each note in three-dimensional space using chaotic modulation functions. Combined with the True Unison engine, these tools generate extraordinarily dense, spatially compelling sounds.
The PolyKB III suits designers seeking sophisticated morphing control and per-voice modulation depth. Its strength lies not in authentic vintage emulation but in modern sound design capabilities grounded in analog modeling principles. For producers working with complex pads, evolving leads, and textural synthesis, it represents a genuinely capable tool.