60Hz Hum coming from speakers when power adapter is plugged in?

[RaptorJesus]

I bought a set of speakers for my MBP today (Logitech X 240 3.1)

And Ive noticed that when the power adapter is plugged into the computer, a 60Hz hum comes from the speakers. Playing music covers this hum up pretty well though. The second I unplug the power cord the hum goes away. I have tried different combinations of hooking one up a power strip and the other directly to a wall outlet thinking that might help.

Its nothing catastrophic, but has anyone else had a similar problem? If so what have you done to remedy the situation?

 

[alphaod]

You need to use the optical out and an external soundcard with a filter to clean the sound up.

 

[Sun Baked]

Ground loop hum is common enough Apple has multiple technotes on it.

Macintosh: Solutions for noise in the audio signal

 

[nephilim7]

it's not an apple problem, it's a ground loop problem. Try the 3 prong plug in, if that doesn't fix it make sure everything that connects to the computer goes through one circuit.