I get the robot crackling sound as well after 1.5 hr and I dont think its solved in 10.8.1. My work around is connecting an old JBL sound dock to the headphone jack of the MB Air June 2012 so I dont notice this problem anymore and the sound is much better anyway. It's obviously not good that Apple hasnt provided a solution as yet.
The other nuisance is a difference issue. The fan noise (6500rpm) when streaming full screen on the Thunderbolt display with Flash or Silverlight. The websites I require are using these players so Flash player warning plugins etc are no good for me.
We know these programmes use a lot of resource of the CPU but I can stream video on the thunderbolt quit happily as long as I dont click on the "full screen" button.
Put your MB Air on a BookArc stand which keeps the fan between 4000-5800 rpm whilst using Silverlight and on the latest flash player software no fan noise at all.
Just to share some personal experiences.
Forgot to say that ocassionally I take my Macbook to watch film on my 42" plasma. I have bought a thunderbolt-HMDI converter for this purpose. My 42" plasma obviously has a much smaller resoluation than the Thunderbolt display so no fan noise at all or sound distortion!
Having said this I do get the occasional blocks flashing across the telly (image distortion from Silverlight to TV picture) but I dont find this a big issue.
The Thunderbolt interface allows me to connect my Mac anywhere with one cable which wasnt possible on my 2008 MB Air, but there's clearly teething problems which I hope are software related.
I have the exact same problems and it's driving me crazy. It's actually very distracting and I cannot focus on my work with the constant buzzing noise. I can't believe Apple has done nothing about this... ***
My problem occurs when the brightness is up, I need to turn the brightness down to almost complete darkness and the buzzing will stop. When I turn the brightess up to arround mid range or higher the buzzing noise occurs. Full brightness is not even an option as the noise is so loud it's unbearable.
Come on Apple...
Still no solutions? *** is going on, Apple. You're really letting us down.
I need to purchase another couple of displays for my office but I don't want to end up with another crappy display that's always buzzing all day long. Can anyone recommend a better display of similar quality and pricepoint? I guess Dell might be a better pick?
Since a couple of days I started having the same issue, and also my display is making noise even when NOT connected: so I have
1) Display unplugged from power and from MacBook Air 2012 -> no noise (obviously);
2) plug in power -> still no noise;
3) plug in MacBook -> noise, worsening over time;
4) plug out MacBook -> still noise, at a lower level.
Honestly folks, this is an issue with the displays themselves (all of the current TB ones). Nothing will fix this - not the OS, not what is attached to it - bar-none. Post if you are having issues, but do not expect a fix, until Apple admits their is a problem with the TB display (which they have not yet - and probably won't). For those reading this - avoid the TB Display until the next Apple Display comes out - maybe then they can actually fix this noise issue.
Personally, I'm living with it for now, as I have actually gotten a bit used to the stupid noise. Next display though, Apple will not be my #1 choice (unless somethere there finally admits there is a problem with the TB displays - [if you ever read this Mr. Tim Cook, I'm talking about you!]).
I have a JBL sound dock permantly connected to the Air when hooked up to the TBD.
(Aux in to Headphone jack). Works well but still a bit dissapointing that this displays internal sound system is unusable. I have reported this to Apple care but the only potential fix was disable your wireless if display ethernet is connected. Never heard anything back and I dont expect them to.
I have the same problem here, I have a MBP with the thunderbolt display. Thunderbolt display has a constant buzzing sound no matter if there is sound playing or not, it starting buzzing right away, only stops when I disconnect from the Thunderbolt Display. Took it to the Genius Bar, they are telling me it might be a power supply issue, but they are stilling running a in depth diagnostic (its been 5 days). So looks like this issue is pretty popular among these displays, I hope they address this issue.
Man, what the ?? is going on with apple? why don't they at least confirm that this is a problem....are they waiting for our warranties to run out before addressing this issue? I have just read this whole post hoping to find a solution but sadly, nothing! I think it's definately a grounding issue or something as Mad sci said but i don't know enough about that to start ripping out prongs! I don't know if this helps but my problem is very similar but i've got a few add on symptoms. I have a standard monitor hooked up with a thunderbolt to vga convertor and my audio is out of an external firepod (firewire) interface with the headphones out going to another high quality headphone amp. If i take the thunderbolt lead out, the audio is quiet but as soon as i put the thunderbolt lead in...boom, there is that awfull hissing sound. The funny thing is that i only noticed when i bought this headphone amp, without the headphone amp, i cant hear the hum noise with my headphones dirrectly plugged into the firepod or even directly into my MBP 10.6 osx...on the other hand i did always notice a funny hum sound with my KRK powered studio monitor speakers, like when i scroll up and down on a web page it changes the oscilating frequency of the hum but it didn't bother me that much. Now i know it's an issue with the monitor, I WANT THAT HUM GONE!! So it seems it's got something to do with amplified sound being amplified again because if i plug my headphones into my firepod i cant hear it but if i plug my headphones into my headphone amp into my firepod i can definately hear it...my KRK speakers have an inbuilt power amp into them so they are taking the audio signal and amplifying them just like the headphone amp is doing. Why does this change things? I don't know, i'm just trying to observe and analyse to diagnose but now i just tried a few things with the thunderbolt conector and my monitor just stopped getting a video signal so that looks like that is a problem with the thunderbolt adapter. .........i'm just wasting my day off away trying to fix this stupid problem....thanks apple for being such a great help and ignoring us!
I purchased a TB display about 18 months ago and for 12 months or so it was fine - life was wonderful. One day I returned home with my 2012 MBP that I had been using with the TB display since day one and there was this terrible, annoying buzz coming from the TB display - not speaker related but like some here related to the brightness level of the display.
In January 2013 the TB display would even buzz when i plugged the display into my MBP and nothing turned on (Display off/sleep, plugged into MBP with the MBP closed and off).
I have the wonderful TB display and I CANNOT use it because of this awful buzzing sound coming from the display. I have tried everything - new Power supply, turning everything off in the home, etc, etc...)
Fast forward to 25March2013, and I purchase a new 27" iMac and I could swear the first night i plugged the TB display into my iMac, NO NOISE. I was so happy~!... but, not so fast on day two of my new iMac-TB display set up - the buzz is back but this time it is not Brightness level (BL) related. If I adjust the BL the sound does not increase as it did with my MBP.
So now I have a 27" iMac sid-by-side next to a 27" TB display and the buzzing noise coming from the TB display but not the imac - thinking this is an Apple TB display issue and NOT a power issue of mine... VERY, VERY frustrated to the point I have started looking into the new Blackberry phone (No more dealing with the Apple inferior products) Yes, I jumped from TB display to phone - make my stand and hit Apple where they make their $$$...
APPLE PLEASE HELP~!
Not sure if this helps anyone (I'm hoping it's not a fluke/ temporary thing, although I have a feeling it is): I had the same buzzing problem. I went into System Preferences > Sound > Output tab > and changed the selection from "USB" to "Internal Speakers" (built-in) and the buzzing went away. Not sure if it was related to a headset/ mic I had plugged in via USB?
May have worked for your specific situation (using internal speakers is not using the TB display speakers), but if you follow this thread, the current TB display has a static/bussing niose issue, and it is not going away no matter what (until Apple fixes this hardware issue - or wait for the next revision of the TB display when the problem is magically fixed with another $1,000+ purchase). It *****, but that is the way Apple is sometimes.
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