Hordijk - Blippoo Box

Original Hordijk, Banana Blippoo Box with the light theremin control 

built by Hordijk himself

By using a nonlinear feedback system, patterns are created that exhibit chaotic properties like attractors, bifurcations, etc. Second, the filter also uses a nonlinear feedback system that can go into ranges where bifurcations occur, which results in the creation of ‘undertones’, where the period doublings create harmonic partials that are lower in frequency as the signal fed into the filter.

The chaotic behavior of the Blippoo Box reveals itself through the repetitive nature of the sound patterns it produces when in a stable state. When a control know is changed to a new position, the box will soon go into an apparent random state and then will find a new balance in a new stable state where it repeats another sound pattern. Tiny changes in a knob setting can sometimes produce dramatic differences in pitches and durations for new patterns. By careful tuning and changing the amount of modulation by the resonator, many timbral structures can be given to a pattern. Still, the particular design of the resonator and how it reacts when excited by the chaotic core of the Blippoo Box will impose a certain sonic character on the final sound, giving the instrument its own personality.