[Alex Lynham] has been creating digital guitar pedals for a while and after releasing the Atom Smasher, a glitchy lo-fi digital delay pedal, he had people start asking him how he designed digital effects pedals rather than analog effects. In fact, he had enough interest, that he wrote an article on it.
The article starts with some background on [Alex], the pedals he’s built and why he chose not to work on pedals full-time. Eventually, the article gets to the how [Alex] designed the Atom Smasher. He starts by describing the chip he used, the same one that many hobbyists, as well as commercial builders, use for delay based effects – the SpinSemi FV-1.
The FV-1 is a SMD chip used for digital delays and other effects that require a delay line – reverbs, choruses, flangers, etc. It’s programmed with an assembly-style language called SpinASM. [Alex] goes over some of the tools and references he used when designing for the pedal. He also has a list of tips for would-be effect pedal designers which work whether you’re designing digital or analogue effects.
[Alex] ends his article saying that, in the future, he might make the schematic and code available, but for the moment he’s not. The FV-1 is an interesting chip, and [Alex]’s article gives a nice high-level look at its features and how to develop for it. For some interesting guitar pedal related articles, check out this one using effects pedals to get better audio in your car, and here’s one about playing with DSP and designing a pedal with it.
