Software developers Xils have just announced a new software synthesizer. Available in AU, VST and RTAS formats, the PolyKB is apparently an emulation of a rare French polyphonic synth, by which we think they mean the RSF Polykobol.
One of the hardest parts of the original to model was apparently the continuously variable shape of the two oscillators, which can be modulated to morph seamlessly between triangle, saw and pulse waves. Xavier Oudin, Xils’s chief developer, says he managed to achieve this without any aliasing, with the use of band-limited impulse trains (BLITs). This process involves mathematically approximating the desired waveform, and limiting the bandwidth of the approximation to avoid the generated wave’s frequency exceeding half that of the sample rate.
Other features of the PolyKB include a 128-note step sequencer, two ADSR envelope generators, a four-pole low-pass filter, two LFOs, a Sample & Hold function, an arpeggiator, built-in chorus and delay effects, and a choice of polyphonic, monophonic and unison modes.
You can check out audio examples of the PolyKB on the Xils web site (www.xils-lab.com), and UK distributors Smart Distribution say that the plug-in will be available from the end of March, at a price of £129.
