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Mac G5 static noise/ beeps through audio output Mixers (Analog)
Old 19th April 2006
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zulusound's Avatar

Thread Starter
Mac G5 static noise/ beeps through audio output

I have a first gen. Mac G5 dual 2.0 ghz and the analog audio outputs emit a static sound tied to processor use and "mousing", and a "beep" every second or so. I know this is a common problem... But I am curious if anyone has had this issue FIXED, by replacing the motherboard, the logic board, the power supply, etc? I did have my PS switched out (to revision E) and though it helped with lower fan noise, the sound coming out the outputs are the same. I am curious if switching out any of the other parts has helped anyone out there, as I still have a few months on my APP. This is completely ridiculous, considering this is considered a "professional" machine.

Evan in Seattle
Old 19th April 2006
Gear maniac
Anonymatt's Avatar

Most likely culprit is interference from the video card. Keep it away from the audio interface, or replace it with one that has a good reputation for minding its own business.
Old 18th September 2006
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jahtao's Avatar
yes its ridiculous. The work around is install CHUD developer tools from the osx install disk and uncheck allow nap in system preferences' processor section.

Apple will apparently replace these power supplies free! I'm just looking into it now... can't find much info tho'... got a number to ring from an apple service centre.
Old 18th September 2006
Gear maniac
Harsh's Avatar

Please give us this number if you have it. I have been using chud, and it's just an annoying step to take. It also left off for too long causes alot of heat from the computer.
Old 18th September 2006
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jahtao's Avatar
Its a uk number G. Just print off the apple technical article #86523 and take it to a service centre that's what i did. Alternatively start by readin the document and follow its instructions!

They should be getting back to me in the next couple of days, i am ON THIS - its getting sorted one way or the other - watch this space!
Old 20th September 2006
Lives for gear

there's a power supply recall apparently.
Old 10th February 2008
Gear Nut

Can anyone give me an update on this situation? I've been more and more irritated by this noise from my mac g5 as well and would love to find a solution. Thanks.
Old 10th February 2008
even if there was a defect that exacerbated the issue, it is a pretty common reality with computer hardware for leakage such as this to find it way into the audio circuits, most likely through the shield / ground of the lead.

i'm reasonably confident that if you were to put in an isolation transformer, it would fix your problem. i'm hoping that you are using the built in analog outputs for non-critical applications...

on the cheap end... - Car: Accessories: Car A/V accessories: Ground Loop Isolator

something a bit more professional...
JENSEN TRANSFORMERS, INC. - ISO-MAX® Audio Isolator Products
look at either the CI-2RR or PC-2XR depending on your application
Old 10th February 2008
Gear Nut

Thanks for the suggestion. I'm not sure how I would use those--the Radio Shack for example, since I'm not using RCA connections.

I should mention that part of the problem seems to be related to the firewire connection I'm using to connect my RME Fireface 800. I thought that the Fireface might be the problem until I turned the unit off and disconnected it, and the Mac made the same noise. I find that the Mac generates the static/beeping noises at a low level, and once a firewire cable is plugged into the Mac's firewire port the noise gets much louder, even when the other end of the cable is not connected to anything.
Old 10th February 2008
...I misunderstood your problem. I have seen these transformers fix problems when using the analog outputs of the computer itself.

Can you describe all the components hooked up to your computer, including non audio hardware, how it is connected, even going into details about how power is connected, etc... I would be curious just to see if there is something else that could be a contributing factor...

Also, when you hear the beeping and you disconnect our interface, for example, where are you actually hearing the beeping noise coming from? The internal speaker of the Mac? A set of speakers hooked up to another interface or the built in mini-jack output?
Old 12th February 2008
Gear Nut

Hey tsvisser,

Thanks for your feedback here. Here's how my system is set up:

8 space rack, with a Juice Goose power conditioner up top. Everything is plugged into the Juice Goose, including one additional power strip into which a few external hard drives, and the wall warts for my RNC and Presonus headphone amp.

Also in the rack are an HHB Radius and Joemeek channel strips.

RNC compressor.

On the bottom, an RME Fireface 800 interface.

2 space rack below the 8 spacer holds a Distressor adn Great River MP-2NV.

All these are connected to the RME Fireface with TRS cables and powered by the Juice Goose.

RME outputs 1 and 2 carry the stereo mix to a Mackie 1202 VLZ mixer which is on top of the rack. From the Mackie the stereo signal goes to a Presonus headphone amp and then to Mackie 824 monitors (the Presonus has a monitor mute switch for the speakers).

Of course the RME signal goes into the Mac G5 (2nd iteration?) via a firewire cable.

I think that covers it.

In terms of diagnosing the noise problem, I think it's related to the firewire cable. The noise comes through the speakers and headphones but does not make it onto the recordings (thank God).

I systematically removed a number of the devices from the interface and from the power conditioner. The only difference came when the firewire cable was removed from the G5. Even then you could hear the noise but it was at a very low and insignificant level. As soon as the firewire cable is plugged into the computer the noise was significantly amplified through the system, and it was the same whether the RME itself was plugged into the other end of the cable or not. I experimented by using a different firewire cable and alternate firewire inputs on the G5 with the same results.

Based on earlier posts on this thread there may be a power supply issue with this early version of the G5 so I may have to bring the Mac in to have that replaced if nothing else works. If you (or anyone else) have suggestions based on this addition information I'm all ears! Thanks.
Old 12th February 2008
Gear Nut

Oh yes, in answer to the question of where the noise is heard when the interface is off/disconnected, it still comes through the speakers. I guess that indicates that it's not coming through the interface.
Old 12th February 2008
My last idea is to use a device like this... that is supposed to isolate noise coming in on the power supply... don't know if it will help, almost seems like you are picking up airborne RF which is leaking into the G5's (supposed to be ground, but floating?) "earth".

XL-1394 Power Conditioning Cable | Sound Devices, LLC

the next thing to try would be an isolation cable... something that does not connect the power pins on the G5's firewire port, just the data. I don't know of one off the top of my head, but I'm sure something like this must exist out there.

am i reading right that you have speakers and headphones connected to the G5 and not the RME interface or did I misunderstand? if you do, the isolation transformers that I mentioned should work in between the G5 and any output device.
Old 12th February 2008
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Harley-OIART's Avatar

Sorry I am working right now so this post will be blunt and direct :

Solutions Include ->

-A good Firewire Cable from a company such as "Granite Digital"
-A good High End Firewire Card... For example the [ADS Pyro PCI 64] if you are a PCI-X equipped owner.
-CHUD Tools to disable napping, and a script to disable napping so that you don't have to personally disable it every time you boot the computer.
-A new powersupply from APPLE (May or may not fix the problem)
-Kick the machine


Old 22nd February 2008
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piotr's Avatar

Yes: there is a simple Apple Script that checks that CHUD box for you autmoatically, every time you turn your computer on.
It really does solve that problem.
I agonized over this for a day or so, looked around on the web, downloaded CHUD and that script, and all was good.


fw months later I invested in a few extenders for the display and interface, cut a hole in my studio wall, and placed the G5 outside of the studio...

I HIGHLY recommend that. It is such a relief to not hear the constant buzz of the computer! It's unbelievable. Really.

Good luck,
Old 25th February 2008
Gear Nut

Fixed it?

Thanks again for the feedback guys, and thanks piotr for your advice. Mine is a second generation G5 with the old standard PCI slots, not PCI-x, so I don't know if the CHUD technique would work for me.

Having said that, I took the mac to the shop (Tekserve in NYC) last week. They weren't able to tell me much definitively. They weren't able to replicate the noise problem, but said that it might be that a firewire port could have gone bad. The fix for that would be a new logic board at $600. "Um, uh, oh please not that" I thought.

So I took the G5 home as it was. I tried plugging it into an outlet on the other side of the room and plugged it into the recording noise. That is, I could still hear the computer noise but it was very, very low, not at the volume it had been at. Taking a chance I then plugged it into the original outlet of my power conditioner. Again, the noise was pretty much gone. At this point, the noise/static has ceased to be an issue. As a result, I'm guessing that it was a ground loop that served to amplify the basic low level computer noise, and that removing the computer from the system basically eliminated the ground loop. Now the question is: is this elimination merely temporary? We'll have to see. As it was, the noise had gradually gotten louder and louder till it couldn't be ignored as a problem. I'll have to investigate some ways address ground loops, and in the meantime, if the problem crops up again, try to to remove the computer from the system to get rid of the noise again. Anyway, I just thought I'd post a follow-up, and thanks again for the assistance.
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