Speaker Buzz with Mac Mini

What volume level is the mini set to? Do the speakers have their own volume adjustment?
If the speakers do have volume adjustment, try setting the mini's volume to half or minimal level and doing all of your adjustment on the speakers. You may also wish to get some snapon ferrite cores to put on the power cables and speaker wires. If you are putting the power and audio cables near each other, separate the audio from the power, as noise will tend to be inducted when they run next to each other for any distance.

Euchre gives some good advice. But I have a differing opinion on the issue of volume. I contend that one should have the audio output level on the computer at maximum -- to overcome noise/hum on the line (a.k.a. improved signal to noise ratio) -- and adjust the listening volume on the speakers.

In addition to the precautions Euchre mentioned, also make sure that the speakers and Mini are plugged into the same power outlet/power strip.

If that fails, try the speakers with another computer, to see if the problem persists. If it does, then I would say the speaker system is flawed in its design.

Could be any number of devices putting interference on the AC circuit. Even something in another apartment, if you're in an apt. building.

Try a surge surpressor strip that has EFI filtering. Also try ferrite cores, as was suggested.

Want to hear something odd? I am having the same issue with my Mac Mini, but when I boot into Windows XP using the Boot Camp partition, it stops! So buzzing with OS X, but not with XP? I'm confused.

I have the same problem. It actually came on rather suddenly, and only about a week or two into the life of my late 2009 mac mini.

It's a horrible buzz when you connect external speakers (anything POWERED seems to be affected). Actually it only starts when the sound card powers up (when you start to play sound, it suddenly kicks in). If it was grounding problems it would be there all the time, I think.

I've tried everything to stop it. I'm in the UK and have never experienced anything like this before with any computer in my home. I'm not aware of any ground loop interference at all, but just incase I bought an isolator, which did nothing to help.

I'm assuming that there is just a fault with my mac mini, and I've put up with it so far as I've tended to use optical out more than analog. I have also had a number of kernel panics when inserting/removing 3.5mm jacks from the mini - which may or may not be related.

I just plugged in a USB soundcard and that is fine.

Would be very interested to hear if others are having this issue as I would like to know if Apple will fix it without too much fuss.

Regards

Firestarta

p.s Have tested in bootcamp (win7) and the buzzing is also present.

I also have a late 2009 mac mini with a buzz that started less than a month ago. It only happens when the headphone jack is used. One thing that I noticed is that the sound stops if I am using itunes for music playback.

Same problem here and, from what I can tell, the buzzing started immediately after a recent OS update (around 11/19/2010 or so).

Immediately after the required reboot, the loud buzzing began from my powered analog speakers plugged into the audio out jack. Playing any sound from any application stops the buzzing. The buzzing only returns when the computer is awakened from sleep (or is rebooted).

Seems oddly coincidental that it happened immediately following an update... perhaps a change was made the effects when to switch from digital to analog output from the audio out jack?