If you're reading this I figure you know what Arduinos are already. I won't go into here....but i will add that they are amazingly handy doodads, able to do with one chip what a ton of CMOS chips would do, and for only a few bucks.
A few things to think about however when using them for audio:
There are plenty of experimenters boards for Arduinos already, but I couldn't find anything that was audio focused (supported 2 rail power supplies and still didn't fry the arduino, had a sandbox area, had a place to drop a 8V or whatever regulator to separate Nano power from dual rail op amp power etc etc.) so I made my own. What you see here is Rev1 of the "supernanofactory" which I have been using to churn out little projects.
You can get the Eagle BRD and SCM files for this here and the gerbers here. I also have a DOCX (Microsoft Word) file you can use to write notes for the OpAmp settings you choose. Get that here.
There are a couple of mistakes on this REV1 build. First, you are going to need to connect the V++ input to the left pin of the regulator. Otherwise, nothing powers the regular on the board at all (doh!). Second, I accidentally hooked D2 pin to ground. If you want to use D2 for something useful, cut that trace.
I already have REV2 of the SNF done and fabbed, but I wanted to see what else was lurking out there bugs wise so I used it on a couple of projects already: you can read about these on my blog: the random gate and the SynthDVM. Zip of Synthdvm schem is here. Both make extensive use of most all the board and both work well with the above fixes. More to come.
Like the Supernano Experimenter Board above, I wanted something I could use to mess w/ ATTINY chips. I wrote some blog posts about these little dookies: getting started, pros and consand interrupts. If you want to see this experimenter's board used in an working DIY synthesizer module, check out my 4051 CV switcher blog post.
here's the schematic
here's the board
some downloads for this....