Mac Mini Audio Trouble Options

[JBeat]

I'm a first-time Mac user, and first-time poster on this site. After spending way too many years fighting Windows PC's, I finally made the switch and picked up a $599 Mac Mini w/512MB of RAM. As I've heard many say before, I'll never go back, I'm already a Mac fanatic after two weeks! I love everything about the Mac, especially Garageband, however, I'm getting a buzz when my speakers are plugged into the headphone jack. I've tried several sets of speakers, with the same result. If I keep the volume of the speakers very low, I can't hear the buzz, but I have to max out the Macs volume, and sometimes it's not quite loud enough. It's frustrating because I have a Creative 2.1 system with subwoofer, but I can't cut it loose on my tunes. Does anyone have any suggestions?

Thanks.
JBeat

[Vincent Online]

Sounds like a ground loop. One thing that may help is to make sure that all your gear is plugged into the same powerstrip. If it still hums, you can try using a Ground Lift (A 99 cent 3 to 2 prong power adapter).... also, make sure your audio cable is good.

While the buzz problem can and should be solved, eventually you may want to kick your audio quality up a notch by buying an audio interface. For the money I like the MOTU 828MKII or Traveler. Then you'll have not only higher quality audio, but more ins and outs...

www.MOTU.com

-Vincent

[editbrain]

hard to believe that he is getting ground loops from a set of computer speakers and a headphone jack.
i don't really think this is the problem. what happens if you hook your old computer to the same outlets and use the same speakers? i mean did it buzz when you used your old computer?

if it did not happen when your old computer was plugged in using the same speakers sounds like a power problem, but not a ground loop.

[jannop]

What Editbrain - are you kidding? Sounds exactly like a ground loop problem. He is connecting Mac Mini to a sound system using headphone/line out - the cure are the things Vincent mentioned...

[editbrain]

you have to be kidding me.... if it wasn't making noise before he got the mac mini then why would it be a ground loop now?

i have had four G5's replaced by apple because there power supply's could not pull the load. they tried to contribute it to a ground loop, but that wasn't the problem. it was faulty powersupplies. this is why i am asking if he had the problem before the mac mini. possibly apple is still making crappy power supplies. which would contribute to the noise. it would contribute to noise coming from the speakers because you would hear the power supply buzzing and whining when extra load is put on it.

This post has been edited by editbrain: Fri 4 Feb 2005, 14:39

[JBeat]

Thanks for the response guys. I agree with editbrain, I can't see how it would be a ground loop. Nothing has changed except that I unpugged and removed my Windows tower, and hooked up my Mac Mini. The speakers were left plugged into the same power strip, and I just plugged them into the headphone jack on the back of the mini. I even tried another set of 2-piece powered speakers to see if the 2.1 system was the problem, but I get the same buzz. It was the same with them, I could turn them way down and crank up the Mac's volume, and I didn't hear the buzz, but cranking the speakers gives me the loud buzz. I have AppleCare, but I haven't called them yet, just wondered if anyone else had this trouble.

JBeat

[ourmanflinty]

One thing jbeat....the methodology in music systems is always to keep your source as loud as possible..this means that you have good dynamic range at the outset and it keeps noise as low as possible...with computer speakers this means always always having the mac volume all the way up, itunes up, garegeband up , all of them up and using the creatives volume control to manage the level through the speakers.
See what your results are after that ok..

Um, is it a buzz or a hum?
You know, buzz like when a crt monitor's too near a guitar or a cable ( turn the screen off to check ), hum like er, 50 /60 Hz mains frequency sort of a hmmmmmm not a bzzzzzzz, not a click click brrrr or a squirt squirt cheepp cheep chirrrrrrt or any of those type either

[editbrain]

[QUOTEnot a click click brrrr or a squirt squirt cheepp cheep chirrrrrrt or any of those type eit[/QUOTE]

that is so funny....

but he is right. I have just had the absolute worst luck with apple power supplies being faulty. it took 4 G5's to get one that worked.
guitar cables, monitors can contribute to the hum/bzz. but i think that you are more inclined to have the problem the whole time you have used your computer not just all of a sudden if it were monitor/guitar/or ground loop.

one thing to think about also is that if you are using a heavy plug and it is pulling down on the connector you will get a buzz from the jack. happens in my powerbook if i use a heavy cable and it pulls down on the jack from hanging i get a bzz. also the cdrom on my powerbook makes noise through the headphone out jack sometimes. this is again due to the power distribution of apples computers.

[JBeat]

It's definitely a buzz. The Mac is right next to my LCD monitor, but the buzz doesn't stop when I turn it off. Since it didn't buzz on my PC, and it buzzes with different speakers attached, it has to be originating with the Mac. I've always had sound cards in my PC's, so I never used the headphone jack to run my speakers, I was wondering if that is a common problem when running off of the headphone jack.

JBeat

[ourmanflinty]

an lcd, ah well they don't cause noises so that's not it.

Maybe the screening on the mac is not as good as it could be.
i wonder if the jack out is impedance matching like ibooks etc.

remember, always leave the mac volume up.

Call applecare, or check the apple website support for any discussions on the mac mini if it's common to mini's there'll be others in your boat!

[lepetitmartien]

If it's a ground loop somewhere, the frequency is 60 or 120 HZ in North america or 60 or 100 Hz elsewhere. [corrected, did quite SOME mistake, and nobody told me!]

If it's a peripheral, moving it will change the buzz.

Is the noise around on headphones too ?

There has been recursive issues of buzz coming from Apple laptops (not to mention some power units in desktop computers). If it's the power unit, Apple will take care of that. I don't remember the solution for laptops… must be somewhere around…

Tell us if the sound chain is up all troughout.

This post has been edited by lepetitmartien: Sun 6 Feb 2005, 05:40

[JBeat]

I had not thought to check if the buzz exists thru the headphones, I hooked up my speakers before I turned the Mini on. It does buzz quite loudly thru the headphones, so I don't think speakers are the issue at all. I'm going to call AppleCare next week and see what they have to say. I really don't want to give up the Mini now that I've become so enamored with it, and I can live with lower volume for awhile. The Mini is so hard to find right now, I might just wait until they are regular stock items in the stores, and return it if I have too.

[lepetitmartien]

Yup, if it's on the headphones, it comes from inside the mac.

Haven't seen a topic on it on specific hardware forums so it seems you've found a nasty little duck… Applecare to the rescue!

I've corrected the frequencies, I mixed up a little

[Vincent Online]

I had not thought to check if the buzz exists thru the headphones, I hooked up my speakers before I turned the Mini on. It does buzz quite loudly thru the headphones, so I don't think speakers are the issue at all. I'm going to call AppleCare next week and see what they have to say. I really don't want to give up the Mini now that I've become so enamored with it, and I can live with lower volume for awhile. The Mini is so hard to find right now, I might just wait until they are regular stock items in the stores, and return it if I have too.

Do you have something plugged into the Audio Input when you're getting the buzz?

[JBeat]

The Mini doesn't have an audio input, just a headphone out jack.

[jannop]

OK, but I think the main reason to the question was do you have anything connected to the Mac? If you hear the buzz in headphones while absolutely nothing is connected to the Mac mini (no audio input device for example) there is unfortunately something wrong with your Mac. If the buzz is present only when something is connected it is most likely a ground loop (in spite of some contradicting opinions...).

I would like to hear if the buzz is still present while nothing is connected since I'm a professional musician considering the purchase of mini...

[editbrain]

you are way off base. if the problem did not exsits before the purchase of the mac. there should not be a ground loop now unless there is a power problem with the mini. i don't know were you keep getting this ground loop theory. it sounds like you read about it on another forum and want to use it to solve this persons problem, when in deed he has noise, but not a ground loop. are you saying that he has a ground loop between his headphones and his computer. since when do you plug headphones into a wall outlet?
it is good that your a pro musician, and probably have had some ground loop problems in your past, but this is a hardware problem with a computer. just because it is in a music forum does not mean that the issue has to be studio related. several other forum users have trouble shot this issue, and this ground loop thing has been ruled out as far as i can tell. do you want to help this guy or not?
i for one have had major issues with apple power supplies so i speak from experience. i have worked for apple fixing 15" and 12" powerbooks. i know the problems that arrise from there power issues.
i have had to have 4 G5's to replaced by apple. not because of ground loops, but because of power distribution problems with there crappy power supplies. ( i thought i mentioned this in another post)

anyway. can anyone please tell me the last time that someone had a ground loop between there headphones and a headphone jack?


thanks,

editbrain

[JBeat]

It sounds like a power supply problem from the research I've done, and the responses here. If so, it is easily resolved since the power supply is external on the Mini, I'm sure AppleCare can ship me out a new one. There is another possibility that I thought of today, though, I realized that the power brick is laying amidst a spider-web of various wiring behind my desk, including a couple of surge-suppressing power strips. I wonder if all of that wiring might be the cause of the buzz? I will try moving the brick tonight, and also try plugging it directly into a wall outlet, instead of a power strip, and see what happens.

JBeat

[Vincent Online]

you are way off base. if the problem did not exsits before the purchase of the mac. there should not be a ground loop now unless there is a power problem with the mini. i don't know were you keep getting this ground loop theory. it sounds like you read about it on another forum and want to use it to solve this persons problem, when in deed he has noise, but not a ground loop. are you saying that he has a ground loop between his headphones and his computer. since when do you plug headphones into a wall outlet?
it is good that your a pro musician, and probably have had some ground loop problems in your past, but this is a hardware problem with a computer. just because it is in a music forum does not mean that the issue has to be studio related. several other forum users have trouble shot this issue, and this ground loop thing has been ruled out as far as i can tell. do you want to help this guy or not?
i for one have had major issues with apple power supplies so i speak from experience. i have worked for apple fixing 15" and 12" powerbooks. i know the problems that arrise from there power issues.
i have had to have 4 G5's to replaced by apple. not because of ground loops, but because of power distribution problems with there crappy power supplies. ( i thought i mentioned this in another post)

anyway. can anyone please tell me the last time that someone had a ground loop between there headphones and a headphone jack?


thanks,

editbrain

While it seems that this may be a hardware problem with the mini, I've seen where something like a monitor, or a printer attached to a computer could be causing a ground loop... LOL

[editbrain]

i agree. sorry did not mean to be so hasty, but i think that most of that came from dealing with apple and now seeing it appear in there new product line. i just don't know if apple gets it.

no offense sorry for the rant

[JBeat]

No luck, guys. I tried moving the brick as far away from wires as I could, then I tried plugging into a wall outlet instead of a power strip, and then I tried plugging into a different power strip. Same result... I think it's time for AppleCare to the rescue!

JBeat

[ourmanflinty]

Do you have a test meter or an oscilloscope...you could measure DC levels coming from the power supply, check the rails as it were. You can also measure the AC present on DC rails, this would be called 'ripple' and will cause hum, noise, buzz etc in equipment, seeing it on a scope is a far better method as the visual feedback of a jagged saw like DC rail instantly tells you why your unit sounds pants!! Measuring it 'under load' ie plugged in and switched on, is preferable as psu's will often be fine when they're not 'stressed' but will go west when something is asked of them..
Can you tell what the psu puts out, one rail, two or more, what the rating is etc? If it only puts out one rail then there must be some kind of regulation board inside the minimac..Never seen one, I should imagine it's a little switch mode supply..

[editbrain]

ourmanflinty,

don't you think that it would be easier just to send it to apple and get a new power supply?

[JBeat]

The problem is resolved!! It didn't take the AppleCare rep very long to isolate the problem, and it turns out that there was nothing wrong with my Mac Mini, or its power supply. The rep had me take out the bluetooth usb device that I was using for my Apple bluetooth wireless keyboard and mouse, and hook up a wired usb keyboard and mouse that I had. As soon as I booted back up, the buzz was gone. I had the bluetooth device in the usb port right next to the headphone jack, and I guess it was causing interference. The easy solution was to move the bluetooth device to my usb hub on the other side of the desk, and the buzz is gone. Sometimes we overlook the easy things while looking for the complicated. Thanks for all of your responses, it's good to know you guys are there to help.

[editbrain]

very nice. i am glad that you did not have to do without your mac. i stand corrected.

[ourmanflinty]

wow bluetooth buzz that's a new one on me!