Homebrew Sound card Followup
Back in May 2011 I posted a description of a sound card I built based on the PCM2904 . At the time I made the observation that since I was primarily interested in digitizing the audio the circuitry related to playback was superfluous and could be removed. The expectation was by doing so the printed-circuit board could made much smaller, making it easier to integrate into other projects.
It turns out this was the case. The pictures below show the original sound card next to the redesigned board. The redesigned board contains only the circuitry needed to digitize the audio and is approximately 60% the size of the original, even making no particular effort to minimize the board size.
I’ve not included a schematic here since, as I mentioned before, it’s basically the circuit from the PCM2904 data sheet. However, for those who might be interested, you can order the boards through BatchPCB. Both boards use surface mount components but they are of reasonable size. Experience with surface mount soldering (and a big lighted magnifying glass) would be useful but I put together both these boards using a standard Radio Shack soldering iron so it can be done. Even so, I would not consider this a beginners kit.
PCM-2904 Sound Card
PCM-2904 Audio Digitizer
Update: For a simpler example putting this together using stripboard and discrete components go here.
Update #2: It’s been brought to my attention that the links above won’t work for finding the sound card or audio digitizer PCBs. To remedy that I’ve pushed the Eagle files to my GitHub repository.