The XILS V+, inspired by the Roland VP330, is based on a Top Octave Divider oscillator. Under this strange name is hidden the heart of almost every electronic organ or strings machines built in the 80’s. A very clever concept to get 49 notes or more of polyphony without having to manage 49 or more stable oscillators, or the nightmare of having to tune 49 or more oscillators! Only one square oscillator, oscillating at a very high frequency (the “Top Octave”), has to be designed and adjusted. This oscillator is “divided” to provide the 12 standard tempered frequencies over 4 (or more) octaves, these frequencies are then used to build the waveform of each of the 49 or more available notes. As a matter of fact, all the notes are kept in phase, hence no drift between octaves (see the videos comparison between the hardware and the software).

Another benefit is that there is only a single tuning circuit for the whole keyboard and then when using the envelope glide, all the notes are modulated in the same manner. This is the limitation which gives this very special, very recognizable effect used by a lot of electronic music artists. For some examples of the unique VP330 sound, simply jump to the 5-minute mark of “Movement 1” from Vangelis’ 1985 album “Mask”, or listen to the opening music of the groundbreaking 1982 film “Blade Runner”.