I normally use a mini jack cable to connect the audio out of my laptop to my guitar amp to listen to music.
When the computer is on battery I have no problem whatsover with the sound quality. However, the second I plug in the charger to the laptop I get a lot of noise in the guitar amp.
I have Windows 7 on dual boot and this problem doesn't happens there, which allows me to conclude that this is software problem of some sort.
Any idea how to solve it? Thanks.
I had the same problem in a Samsung notebook, I couldn't find a solution, So I updated from 9.04 to 10.04. The noise while charging was gone. But maybe you should try another thing before doing this, it's a little too drastic ;)