Intellijel Designs Rubicon

Not long after David Dixon finished the Dixie design he began working on a totally novel approach to implementing TZFM, thru-zero frequency modulation. After almost a year of experimenting and many PCB revisions later we are pleased to present what is surely David’s masterpiece as far as analog VCO design is concerned.

The Rubicon is packed with the following features:

• Triangle core
• Switchable linear and (for the first time in any module) exponential TZFM
• Linear index VCA for dynamic control of TZFM depth
• Symmetry control (full clockwise is normal, full counter-clockwise gives reversed waveforms, centered the VCO is at 0 Hz) with CV
• 12 primary waveform types: sine, sigmoid, double sigmoid, triangle, saw, double saw, zigzag, square, pulse (center modulated), pulse (edge modulated), double pulse
• Suboctave circuit (similar to the one found on the roland sh-101) with -1 and -2 octaves. (suboctave output is affected by fm just like the main signals.)
• Soft sync (aka reversing sync) with attenuator
• Hard sync with selectable reset direction (determines if the triangle starts moving up or down after a reset, very useful in LFO mode)
• Pulse-width modulation and exponential FM with dedicated attenuators.
• Wide frequency range:
  hi range (VCO): 1 hz to 24 khz
  lo range (LFO): 0.01 hz (100 seconds) to 240 hz
• precise tracking within 0.1% over 8 octaves
• 18hp and skiff friendly!