Rubicon

Thru Zero Triangle Core VCO, Mk1, Panel B

Not long after the 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 cw is normal, full CCW gives reversed waveforms, centered the VCO is at 0 Hz) with VC input

12 primary waveform types: sine, sigmoid, double sigmoid, triangle, saw, double saw, zigzag, square, pulse (center modulated), pulse (edge modulated), double pulse

Sub-octave circuit (similar to the one found on the Roland SH-101) with -1 and -2 octaves. (Sub-octave 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)
PWM 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!