What's up with the weird combined audio/video jack on the pi? I was using a beagle bone and a USB sound dongle but am switching to a pi and thought I would use the built in audio. It appears I would need a cable to convert to RCA and then back to 3.5mm audio plug? Or make up my own custom cable adapter. I am not interested in the video. Might be easier to plug the USB sound dongle in since the later pi's have multiple USBs. Also was surprised to see that the sleeve is not ground - seems strange. If I just insert a standard stereo plug with shorting out the video damage anything?