I have had a pi 3 B for a few days.
I get my sound out of two pc boxes (not hdmi, they are analog). I have installed raspbian (jesse), and Kodi on it. If I start Kodi from Raspbian the sound is good, but if I play a mp3 or a video (webbrowser also) in Raspbian the sound always has a loud noise, so I can't hear anything. I don't know why Kodi works well with sound and Raspbian does not. Before I try a USB sound-card, I want to know why it makes such a difference, and how I can fix it without a USB sound-card.
Google didn't help me, so I hope I can find help here.