Welcome to SpinCAD Designer!

SpinCAD Designer is an open source Java project which allows creation and audio simulation of patches for the Spin FV-1 audio DSP chip. It should be used with the Java Runtime Environment or Java Development Kit 1.8 or later. It has been tested on Windows, macOS, and Linux.

Where to download it?

What kinds of sounds can I make?

At the link below are just a few of the... BILLIONS (?) of sounds which are possible with SpinCAD Designer. Now make me proud and go out and whip up something new! I had my own version of the "Universal Fire" last year (an M.2 drive with years of stuff on it fried) so I don't actually have the design files for most of these any more. Oh well! Stuff happens.


It all started around 2010 when I was looking for something fun to do with technology and music. I hardly remember it now but I purchased a Spin FV-1 development board. The FV-1 is a special purpose DSP chip used in many guitar pedals. Read more about it here: http://www.spinsemi.com/

Even though I studied DSP theory in university many years ago, I found the FV-1 assembly language to be baffling and somewhat cumbersome. Once I got familiar with the way certain things were done, I looked for a way to make putting these things together more efficient.

The first thing I stumbled across was a YouTube video from Andrew Kilpatrick showing something he had developed called "ElmGen", a Java library which simulates the FV-1.

For a long time I didn't get it... what difference would that make? Well there are two big deals about this.

#1 If you build your patch this way, you can simulate it on your PC or Mac without needing a real FV-1 chip, which streamlines the development process considerably.

#2 You can leverage aspects of Java which are lacking in the FV-1 itself such as object orientation and the ability to add a GUI on top of it. Which is exactly what I did when I developed SpinCAD Designer!

Since then, SpinCAD Designer has been used in the development of a variety of hobbyist and commercial products. It's not the be-all end-all for FV-1 development, but some companies, such as Erica Synths from Latvia, put out several very creative products using nothing but SpinCAD Designer to develop their patches.

Visit: https://www.ericasynths.lv/shop/eurorack-modules/by-series/black-series/black-hole-dsp2/ for an idea of how far out you can get with SpinCAD Designer!

The pages on this site seek to explain the use of the SpinCAD Designer program so that you can get the most out of it.

Why Do I call myself "Holy City Audio"?

It's pretty simple. I live very close to Holy City, CA, which is currently considered a "ghost town" between Los Gatos and Santa Cruz. Back in its heyday it was the center of what I can only describe as a cult. This has been well documented in Betty Lewis' book. It's not what I would call a proud history, but hey, I just live across the street from it and frequently walk along its paths.

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