Audio via HDMI is digital so there really are no problems there. The 3.5mm audio jack is just a simple PWM (see plots at http://www.crazy-audio.com/2013/11/qual

Audio via HDMI is digital so there really are no problems there. The 3.5mm audio jack is just a simple PWM (see plots at http://www.crazy-audio.com/2013/11/quality-of-the-raspberry-pi-onboard-sound/ http://www.crazy-audio.com/2013/11/quality-of-the-raspberry-...). Sound quality is actually quite improved upon the first release, but it's never going to be great.