It looks like the P5 header that it uses was only added in rev2, and "intended to be a suitable attachment point for ... audio codec boards"[1]. It's definitel

It looks like the P5 header that it uses was only added in rev2, and "intended to be a suitable attachment point for ... audio codec boards"[1]. It's definitely a shame that things are fragmented, I was considering adding audio to my old Pi. But at least they're cheap enough to justify buying a second one :-) [1] http://www.raspberrypi.org/archives/1929 http://www.raspberrypi.org/archives/1929