This CU is an attempt to port Rob Hordijk famous Benjolin synth to the 301 platform. At the heart of the Benjolin is the Rungler circuit (which i will release next), a peculiar device made of an 8 stages shift register and a crude digital\analog converter. It is clocked by Oscillator 2 and fed values by Oscillator 1. But both oscillators can then be frequency modulated by the Rungler itself, enabling a plethora of cross\self mod that gives birth to chaotic behaviours and patterns.
In the mixer section you can set levels for various individual outs. The main output is a sort of PWM obtained by comparing the two triangle outs of the vco’s added to the rungler out. It’s the only out passing through a Low Pass Filter.
Keep in mind that in the original VCO’s and VCF are analogue, and the rungler is really primitive (CMOS) digital technology, so this version will never sound as organic as the true one. Nevertheless i find it awesome in its own way
- VCO1 freq: 1v/oct pitch control of oscillator 1
- Rung1: how much the rungler modulates the frequency of VCO1
- VCO2 freq: 1v/oct pitch control of oscillator 2
- Rung2: how much the rungler modulates the frequency of VCO2
- cutoff: 1v/oct control for cutoff frequency of the filter on MAIN out
- q: resonance control of the filter on MAIN out
- Rung F: controls how much the Rungler modulates filter frequency
- tri1: level of triangle output of VCO 1
- pls1: level of pulse output of VCO 1
- tri2: level of triangle output of VCO 2
- pls2: level of pulse output of VCO 2
- MAIN: level of the main output
cpu: about 30%
firmware: 0.4.11 or later
tips: experiment with slow vco1 and fast vco2 or vice versa. there’s a lot to explore here
notes: this isn’t an exact clone of the benjolin and is somehow simplified. the rungler’s shift register of the original benjolin is fed a xor of vco1 pulse and last bit of the shift register, mine is just vco1 pulse. in the original benjolin you have a loop feature with which you can recirculate datas in the register, i will try to implement that in a future update.
credits and thanks:
Thanks to Rob Hordijk for the infinite inspiration and source of knowledge, i strongly suggest you read his synthesis workshop pages if you haven’t.
Here some additional infos on the Rungler concept.
The hardest part to grasp for me was how to create the primitive DAC, i’ve been illuminated tho by the euroreakt Rungler block for Reaktor 6 made by the great @trickyflemming which i thank immensely for his huge work (i donated when the original euro reakt series came out, i suggest every reaktor user to check it and donate or buy the new reaktor 6.3 compatible version on the Unfiltered Audio website.
Bengiolino.unit (127.1 KB)