I am currently working on my semester project which is a guitar multi-effect pedal using the UDOO Quad and PD. I got everything up and running on the Linaro Ubutu 12.04 LTS build provided by UDOO and I am having strange results with PD. The soundcard I am using works normally when I am using Audacity. It plays wav files and can record the guitar signal correctly but when it comes to PD, a basic osc object or a table read through ALSA produces a strange digital noise, completely ruining the audio signal.

I have also tested this setup with a M-Audio Fast Track Pro USB card and the playback worked without issues, although I could not get the input signal through the adc object for an unknown reason. 

Has anyone tried a similar setup for guitar usage?

Thanks!