Famous for its gorgeous sound and unusual features, only a few units of the original RSF PolyKobol 2 were manufactured in the early 1980s, making it one of the rarest analogue synthesizers ever made. But even if you’ve never heard of the French polysynth, don’t let that stop you from trying out PolyKB III, XILS Lab’s lovingly programmed soft synth version.
Like the original, the PolyKB III features oscillators with morphable waveforms, allowing you to sweep (and modulate) between waveform shapes. Unlike the original’s two, XILS Lab has increased the oscillator count to three, allowing for triple-oscillator Minimoog-like harmonic possibilities. Also worth mentioning are the twin multimode filters, each with a dedicated ADSR envelope, and buttons to choose sources. You could choose to send oscillators 1 and 2 through filter 1 and oscillator 3 through filter 2 with a parallel structure, or filter 1 to 2 in series, or any other combination. There is also an extensive modulation section plus a whole host of extras like XY pads, arp, sequencer, and effects.
But this buyer’s guide is all about the sound of the synthesizers, and in this department the PolyKB III is a revelation. The oscillators are warm and robust while the filters are smooth and extremely musical, allowing for some very inspiring analogue tones. It brings to mind Moog as well as Sequential but really it’s its own beast, and should be heard to be believed.