I wanted to post a quick update about my development of an audio “daughter board” for raspberry pi.
I have a working prototype – and it is sounding good! Its a pretty basic implementation to begin with – I just wanted to get something working before trying anything too silly. It has unbalanced stereo in for recording, and stereo out balanced or unbalanced. No measurements so far – just got rid of the hissing background noise that was bugging me, dead silent now.
I intend to develop this as an open-source project, so follow along if you want to build one yourself. The smallest parts are 0805 so no problem for hand soldering. Version 1, using this WM8731 CODEC chip will be ready soon for public consumption. 9V DC supply (guitar pedal type) will power the whole board including the pi itself. You will spot some bodge-wires (how could I get the DC connector pins wrong???) and dirty hacks in the photo: this is definitely a work-in-progress!
It has a few cool features which I will explain in a later post, just wanted to share this success so far. Any suggestions for preferred DAC/ADC chip to use in the future? Leave a comment…. but no audiophile-phoolery please