OptoBox: Everyone loves (ghetto) VCAs

… because everyone loves VCAs, even ghetto ones.

Once upon a time I had a module called the OptoThing – it used an optocoupler IC to do weird and strange things to an incoming signal (side note: if you want one, you can get it as a super-easy DIY kit)

This, then, is its successor, with a bit of a difference – rather than being a Eurorack module, it is in a compact, desktop-friendly format.

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FilterBox: CMOS abuse for fun and profit

The CD4069UB  hex inverter is an interesting and versatile piece of silicon – you can use it for its intended purpose of inverting a signal, but it is far more fun to put it to uses that its designers probably never thought of. I’ve used it in a number of past modules: a twin-T bass drum module (which was sorta-kinda OK but I’ve fi

nessed the design to use op-amps now), the Buzzsaw VCO, which is based on a design by Rene Schmitz that I’ve fiddled with and the 69er resonant low-pass filter which uses the inverters as linear amplifiers to create a wonderfully unruly and shrieky resonant filter.

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