It is not a too high volume issue on the "in" side. The sound is not distorted, like the volume was too high. It sounds like a really low bitrate mp3 file. Terrible. If I not use the buffer, the sound is just fine. I would really like to use the buffer option, but won't sacrifice crappy sound.

I tried your suggestion but no luck, even with the "line-in" at 0, nothing happends. I tried restarting both centrafuse and the Infill.