The electrical buzzing sound is normal right?

[2contagious]

I don't have any random cracks either, just when stuff is being turned on/off.. It doesn't happen when I connect the speakers to my iPhone running on battery power and it only happens rarely when I use my speakers on my iMac G4..

Also, I just checked the back of 4 Mac Pros (2006 model) at my uni and their PSUs were all buzzing, just not as badly as mine (it was not audible through the front, only through the back of the case)

 

[dissolve]

I don't have any random cracks either, just when stuff is being turned on/off.. It doesn't happen when I connect the speakers to my iPhone running on battery power and it only happens rarely when I use my speakers on my iMac G4..

Also, I just checked the back of 4 Mac Pros (2006 model) at my uni and their PSUs were all buzzing, just not as badly as mine (it was not audible through the front, only through the back of the case)

Thanks for checking out those '06 systems (hope no one saw you with your head against the back of a MP ). I was thinking about the speaker pops and honestly can't remember that happening with my first PSU. I'll try it with my iPhone later today; that's a good idea. Then we at least know it's not the speakers themselves. I don't know enough about the PSU system to understand why speaker popping may occur. Anyone have ideas?

 

[2contagious]

Thanks for checking out those '06 systems (hope no one saw you with your head against the back of a MP ). I was thinking about the speaker pops and honestly can't remember that happening with my first PSU. I'll try it with my iPhone later today; that's a good idea. Then we at least know it's not the speakers themselves. I don't know enough about the PSU system to understand why speaker popping may occur. Anyone have ideas?

haha that's fine, it's art school. they don't mind me putting my head against their mac pros I ordered a high quality screened audio cable that should arrive tomorrow or friday, so I'll see if that makes any difference with the speaker problems.

 

[dissolve]

I tried my speakers plugged into an iPhone and they still pop when changing the speed of a plug-in fan. So the wiring is just bad in this apartment...and I need to get a UPS soon

I noticed something earlier today while doing a Handbrake encode. The PSU go noticeably louder and sounded a lot like my first one: electric buzzing, distinctly not a fan. I checked iStat the entire time and the only fans speeding up were one of the case fans and the 5870. I opened the case to be sure the noise wasn't coming from them and I'm pretty sure it was the PSU. Its fan stayed at a constant 600rpm over the hour I was encoding. Oddly, the noise persisted for at least 10 minutes after the encode, but now it's back to that weird high-pitch noise. I'm stumped.

I've been reading around a bit more and the Apple Support site is full of these issues dating back several years and models ago. I'm surprised not many more on here notice it or have the issue.

 

[2contagious]

A "genius" at the Regent Street store told me the buzzing was normal, it's "the current going through" (lol?!) He said it should not buzz excessively though.. What the hell is going on, I've never heard a buzzing PSU before (in my PC times) :/

 

[nanofrog]

A "genius" at the Regent Street store told me the buzzing was normal, it's "the current going through" (lol?!) He said it should not buzz excessively though.. What the hell is going on, I've never heard a buzzing PSU before (in my PC times) :/

If the PSU were a linear design, it's fairly common (large output values). They require much larger transformers and storage capacities.

But the MP's PSU is a Switched Mode unit (SMPS), so they don't have anywhere near the transformer or storage capacitance for the same sustained output rating. This results in quiet operation, not something that sounds like a huge electromagnet.

 

[dissolve]

If the PSU were a linear design, it's fairly common (large output values). They require much larger transformers and storage capacities.

But the MP's PSU is a Switched Mode unit (SMPS), so they don't have anywhere near the transformer or storage capacitance for the same sustained output rating. This results in quiet operation, not something that sounds like a huge electromagnet.

Print this out, bring it in with you, and read it to the Genius Bar

 

[nanofrog]

Print this out, bring it in with you, and read it to the Genius Bar

But can they read? And if they can, will they?

 

[fensterbme]

I too have the buzzing going on...

I too have a buzzing going on... At first it was pretty silent, but in the last two weeks a buzz has started and it's quite audible from where I sit. I also get pops when light switches are turned on/off on my desk from my speakers (.

I have a 2010 3.33Ghz. Hex Core Mac Pro, with a single ATI 5770. Mine is plugged into an APC Smart UPS 1400.

With my old Windows system (which had an Active PFC power supply) was dead silent, no pops through the speakers (Klipsch promedia 2.1).

It's pretty darn frustrating as other than the buzzing my office is totally silent which makes the buzzing sound all the more annoying.

 

[2contagious]

I too have a buzzing going on... At first it was pretty silent, but in the last two weeks a buzz has started and it's quite audible from where I sit. I also get pops when light switches are turned on/off on my desk from my speakers (.

I have a 2010 3.33Ghz. Hex Core Mac Pro, with a single ATI 5770. Mine is plugged into an APC Smart UPS 1400.

With my old Windows system (which had an Active PFC power supply) was dead silent, no pops through the speakers (Klipsch promedia 2.1).

It's pretty darn frustrating as other than the buzzing my office is totally silent which makes the buzzing sound all the more annoying.

Yeah, I can totally understand you.. my room is completely silent at night and the buzzing drives me crazy sometimes. Maybe I am just hallucinating, but it seems that over the past few days the buzzing noise went a bit quieter (?) The sound ALWAYS got worse when using the sliders in Lightroom, but I can't replicate that anymore now (for now at least).

I do have a resonating vibration sound going on in my Mac Pro, too though.. and the crackles in my speakers About the crackles, a digital to analogue audio converter also didn't help. I wonder what this means? How could the crackles be power/electricity related, but happen on both 3.5mm audio AND optical?! Optical shouldn't cause an electric problem (?)

I got some news btw.. I went to the Apple Store last week and they had a look at my Mac Pro. Got it back 2 days ago and they didn't repair or replace a thing.. said everything was fine with it (??) I got them to get a "repair "genius"" to talk to me (rather than a fake behind-the-counter genius) The genius then listened to the PSU of the store's Mac Pros with me and found the same noise on all of them. He said that it could be that it's either normal or there is some serious engineering fault going on. I also told him about the audio issues I am having and that these two issues are also present in other people's Mac Pros. He told me that they don't do this very often, but he would contact the Apple Engineering team in California about the two issues (I can't remember what he called it.. an "exclamation" or something?!) and get back to me.

EDIT: oh yeah, also I wanted to ask, has anyone ever seen reports of someone using noise reduction mats in a Mac Pro? (on the inside of the Mac Pro's door for example)

 

[dissolve]

I too have a buzzing going on... At first it was pretty silent, but in the last two weeks a buzz has started and it's quite audible from where I sit. I also get pops when light switches are turned on/off on my desk from my speakers (.

I have a 2010 3.33Ghz. Hex Core Mac Pro, with a single ATI 5770. Mine is plugged into an APC Smart UPS 1400.

With my old Windows system (which had an Active PFC power supply) was dead silent, no pops through the speakers (Klipsch promedia 2.1).

It's pretty darn frustrating as other than the buzzing my office is totally silent which makes the buzzing sound all the more annoying.

Can you do a quick test that we did earlier? Try plugging your speakers into another device and flip the light switches. I did that and my speakers still popped. Doesn't make me feel much better about the electricity being delivered to the MP, but at least it's not the system causing the pops. Hopefully the same is true for you.

I got some news btw.. I went to the Apple Store last week and they had a look at my Mac Pro. Got it back 2 days ago and they didn't repair or replace a thing.. said everything was fine with it (??) I got them to get a "repair "genius"" to talk to me (rather than a fake behind-the-counter genius) The genius then listened to the PSU of the store's Mac Pros with me and found the same noise on all of them. He said that it could be that it's either normal or there is some serious engineering fault going on. I also told him about the audio issues I am having and that these two issues are also present in other people's Mac Pros. He told me that they don't do this very often, but he would contact the Apple Engineering team in California about the two issues (I can't remember what he called it.. an "exclamation" or something?!) and get back to me.

That's some pretty cool news. Definitely post back when you get a response. As for me, I've tried to stop putting my head next to the PSU. Ignorance is bliss right? If you get an interesting response from the Apple engineer, maybe I'll bring mine in though. One thing I noticed the other day, I can hear a very, very faint buzz even when off. I know it's still pulling power (~1W) but that was a little concerning.