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Hallivand
Aug 6, 2011, 09:01 PM
Hey all, I have a Quicksilver G4 which i've recently re-activated after a long hiatus, and it reminded me of its audio issue. When i plug in external speakers, it would hiss fairly badly irrespective of workload or what activities I'm doing on it.

Since my G5 has failing HDDs (with little cash to replace), its looking like I might need to bring the G4 back into service. Otherwise it works flawlessly (aside from an odd graphical glitch in Leopard, runs brilliant in Tiger).

Any help/suggestions would be greatly appreciated :D

(not sure of its year, but its a Quicksilver 933mHz single G4 with 768mb RAM)

EDIT: There is no hissing or anything from its internal speakers at all, only from the audio jack.



MAC MAN JW
Aug 7, 2011, 09:32 AM
Hey all, I have a Quicksilver G4 which i've recently re-activated after a long hiatus, and it reminded me of its audio issue. When i plug in external speakers, it would hiss fairly badly irrespective of workload or what activities I'm doing on it.

Since my G5 has failing HDDs (with little cash to replace), its looking like I might need to bring the G4 back into service. Otherwise it works flawlessly (aside from an odd graphical glitch in Leopard, runs brilliant in Tiger).

Any help/suggestions would be greatly appreciated :D

(not sure of its year, but its a Quicksilver 933mHz single G4 with 768mb RAM)

EDIT: There is no hissing or anything from its internal speakers at all, only from the audio jack.

I have the same thing on my QS 733Mhz only it is in the built-in speaker but not the audio out port:confused:

Papanate
Aug 7, 2011, 09:45 AM
From Apple's specs:
Headphones or externally powered speakers connect to the standard headphone jack. The Apple speaker minijack is designed specifically for use with the Apple Pro Speakers -- it connects to a powerful amplifier built into the system.

So what speakers and which jack are you using?

zen.state
Aug 7, 2011, 10:11 AM
Some later G4 towers like the Quicksilver and MDD had the odd and very rare issue of not being grounded for audio. Radioshack or places like that sell a small wire for issues like this with audio that you attach to your towers metal and another piece of metal outside it.

I read about this on an MDD blog once.

Papanate
Aug 7, 2011, 10:28 AM
Grounding issues would produce a 60hz or 50hz (depending on the location)
'buzz'.

A impedance mismatch would produce a hissing noise of varying degrees in relation got the mismatch.

Hallivand
Aug 7, 2011, 03:49 PM
@Papanate I'm using the standard 3.5mm audio jack thats out the back of the unit, with my speaker/amp combo. :confused:

@zen.state Would you happen to still have a link to that MDD blog? I'm curious to know of this fix, since it's a mild annoyance having to use my iPod to play music in place of the G4.

@MAC MAN JW When I searched online, your issue with the internal speaker hissing was fairly well known, apparently plugging something into the audio jack behind it alleviated the "hissing"

zen.state
Aug 7, 2011, 04:00 PM
Here is the blog: http://coolstuff.wordpress.com/2007/02/19/powermac-g4-mdd-cooling-and-noise-reduction/

Are you by chance using Nap mode from the CHUD developer tools? Pretty sure it worsens the issue a bit.

Hallivand
Aug 7, 2011, 04:02 PM
Cheers zen.state, I don't have developer tools installed on the G4, though I did a awhile ago and didn't think there were even an option for Nap mode (I thought they were confined to the G5's)

zen.state
Aug 7, 2011, 04:11 PM
Cheers zen.state, I don't have developer tools installed on the G4, though I did a awhile ago and didn't think there were even an option for Nap mode (I thought they were confined to the G5's)

Nap runs great on G4 7455 chips that were found in later QS's and all the MDD's.

Hallivand
Aug 7, 2011, 04:13 PM
Nap runs great on G4 7455 chips that were found in later QS's and all the MDD's.

Oh sweet, can't wait to try it when I get to my QS again then :D I'll get back in a few days to post how it went, as it's at my other house (in preparation for migrating here).

zen.state
Aug 7, 2011, 04:20 PM
Oh sweet, can't wait to try it when I get to my QS again then :D I'll get back in a few days to post how it went, as it's at my other house (in preparation for migrating here).

What speed is the CPU? It may be a 7450 rather than a 7455.

Edit:

Nevermind. I missed that it said 933MHz in your OP. That is probably a 7455 but some specs have listed some as a 7450.

Dave H
Aug 7, 2011, 06:56 PM
Nap runs great on G4 7455 chips that were found in later QS's and all the MDD's.

Nap works on my mother's B&W G3 with a 450MHz 7400 G4 upgrade.
Adding this applescript (http://cubeowner.com/kbase_2/file_d.php?id=60) to Login Items enables it automatically.

Cox Orange
Aug 8, 2011, 07:03 PM
I know I am a bit late, but... http://support.apple.com/kb/HT2743?viewlocale=en_US