Nick, I picked up a myRio and got to tihnking about this FPGA audio guitar effects again so i pulled down your code to try. It had a couple broken/missing subvi's that i had to find.
I just wanted to point out if anyone else grabs it that you will need the "NI Open Sound Control" using VIPM in order for it to work.
Thanks again for posting this code. Maybe ill see you at a booth playing guitar during NIWEEK 2014!