I recently was messing around with my 8886 with my headset on. As is sometimes the case, there was the clicking and buzzing. Sometimes fiddling with the mike plug will help with that. This time, for some reason, some of the volume settings were off so I was fiddling around with them, muting some, moving the sliders up and down to see what would happen. When I muted the SP/DIV, the buzzing, crackling and popping disappeared. Whoa! Absolute quiet. Total silence. This makes sense too, after I thought about it, the same plugs are used for the mike in, headphones out as for the SP/DIV. Why they don't give the sound output its own set of plugs is beyond me. Well, why they don't get rid of the serial, parallel and PS/2 plugs as well as the floppy is beyond me too. Or why they duplicated existing facilities with the MP3/6in1 reader port or a lot of other questions. They should just ask me.
Anyway, I disgress as usual. So try turning off the SP/DIV and see if it doesn't get rid of all the noise.