Weevil 2024

Voltage Controlled Chaos Generator/Processor

Back in the Old-Blues days, I tried to port the Weevil design into the modular format but it was a challenge.. The circuitry of the regular Weevils is really very simple & the chaos comes from circuit-bending (an unconventional approach!) – the difficulty was how to add voltage-control features to this simple circuitry (modular approaches are quite a bit more involved). So while I did a design back then which was enjoyed by bug-users (SYN1 Weevil), I never thought it quite captured the chaotic sonic worlds of the ‘true’ Weevils.

For a few years I put the Weevils to bed, but have recently come back to thinking on them – so, looking again at modular approaches, I’ve come up with something that I feel works things a bit differently and, while it still feels a bit different from more regular/simple Weevils, it offers a whole host of chaos & noise.

See the block diagram!

First off we have the power starvation core – this unfortunately couldn’t viably be voltage-controlled. Turn the Starve dial fully clockwise for regular/full-power usage. When starved, everything goes a bit nuts, everything interacts & we get to much more noise-based areas, though note that all outputs pass through circuitry to ensure they remain ‘full-strength’ (all are 0V to +10V). There is also a Stable switch which adds a little smoothing – it isn’t exactly stable, but it is more-so/different.

There are two voltage-controlled oscillators ranging from c.0.5Hz to 20kHz from the front panel (they can go slower with external negative CV). There are CV inputs with depth controls & polarity/mute switches for each Osc plus a CV Both input which affects both Oscs. The Oscs track 1V/Oct reasonably well, but are not temperature compensated, nor do they have the best high-frequency tracking. The two Oscs interact a little, especially so when starved. Each Osc has an independent banana output + LED indicator.

The basis for Weevils was a simple cymbal noise-source generator which quasi-ring-modulated square waves together for richly (en)harmonic tones. Here we have a first RM combining the two Oscs, followed by a second which mixes RM1 with an external signal which has passed through a drive/squaring circuit so that it matches the Weevil-core (inc. starvation). This audio input is quite level dependent so do play with the Drive control – you can also input gates/clocks/etc. to the input which can generate some interesting behaviours when using Starve. Note that without an input signal, the output of RM2 will appear quiet (ie. it isn’t silent, but it isn’t regular amplitude).

All in all, the Weevil Module is inherently quite chaotic compared with my other module designs – that is, I feel, its strength & interest! Experiment, feed different signals in, feed outputs back into CV inputs, etc.

https://www.bugbrand.co.uk/product/weevil-module/