Buzzing noise from computer through speakers


I've recently been experiencing a buzzing noise coming from my computer, through my speakers. This noise is consistent and increases/turns scratchy when I scroll a page. I've never experienced this problem before and the setup is the same. I was told it might be a mains feedback loop and so have plugged both the computer and amp directly into a wall socket but this has not resolved the issue.
My setup is a Macbook Pro connected to a Marshall AS50R acoustic amp (second channel, aux connector) via a mini-jack-to-phono lead.

Any advice is greatly appreciated, thanks.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Peter HartCommented:
this may be a duff earth connection or  poor earth on the mains.
have you tried holding a portable radio (switched on) next to the MAC and see if the mac interferes wit hthat?  as it sounds like the MAC does not have suffienct shielding around the motherboard  
I had that problem when I had a wireless mouse.

Stuck in a cordless and the buzzing went away.
pheidiusCommented: This issue is multi-threaded in the Apple forums. The first link is Apple's putative fix. From the amount of threads on this topic there, I wonder if it is definitive though. As i read through the threads I suspect that there is a real board issue at play. You might want to consider just circumnavigating the whole thing until a hardware fix appears by buying a usb device like an maudio pre or a similar firewire device and eschew using the mini-jack out completely. Sad, if it is hardware on their pro line.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Home Theaters

From novice to tech pro — start learning today.