[linux-audio-user] open & free soundcard

Hi friends, for some days I was looking for some open & free hardware and specially soundcards. I find some informations about openhardware... but not really on the question of soundcard (some dac to build yourself). I would like to know if some of you guys using open & free soundcard and if not at least a way to do it yourself... or even if you know people who had a project to release some prototypes or have similar projects. I could be really great to use a gnu/linux plateform with so much & good free audio software and to use an open & free soundcard to record & play this sounds!! thanks for the help Julien