The Doxillator

Necessity is the mother of invention.

Madame Mabuse is a radical environmentalist and a devoted birder. In April 2024 she planned a month-long road trip from southeastern Arizona to the Louisiana coast; an intercept course for the Spring migration routes of dozens of bird species. In order to secure my assistance as driver and bodyguard, she offered me a short bivouac in Austin Texas to visit old friends from my college days at North Texas State University. These friends generously offered me a opportunity to perform on analog synths and I declined. The offer was supremely tempting but wholly impractical. Madame Mabuse and I were traveling in the smallest Prius that Toyota makes, with a months worth of luggage, specialized reference books, and birding equipment. This picture is a normal sized rig for my live performances. There was no way that was going to fit in the car and travel with us for a month. But my friends persisted in their request and I persisted in demurring. This protracted exchange planted a seed of sedition in my admittedly rigid ways of thinking. My approach to live analog performance is to always keep the soundscape in motion. And to always be introducing nuances. This requires a ‘reservoir’ of a lot of voices. One of my principal controllers for this approach is the Dual Ribbon which includes a case for its power-supply, output connections, and a few off-board functions. This case had several square inches of open space in it. Maybe enough space for a compact but dense array of voices.

Long story; short, I did perform in Austin and one of the principal parts of the rig was a complex Oscillator-Pair with a multitude of derived outputs. I called it ‘The Doxillator’.

It’s core is an FM-Pair complex oscillator with a Wave-Folder/Multiplier tacked-on. much in the mold of Buchla’s venerable original 259 design.  

In order to derive more varied outputs I added twists to this old chestnut of a design. These are the processors in the diagram to the right of the waveshaper. I used an ‘internal’ resonant VCF (yellow) to generate harmonics and then I use a comparator to select a variable subset of them. This makes for a very unusual square-wave multiplier that is used downstream to drive a shift-register->DAC staircase wave generator. Another aspect of this embedded VCF design is that when the VCF is driven to self-oscillation. the entire system becomes a 3-oscillator FM source. It accomplished my goal of generating many diverse signals from a patch of leftover space in the Dual Ribbon case.