" I wonder if I can ask you or the readers of Accelerate Your Mac if any else has experienced the problem which I have just noticed.

My G4 Digital Audio makes a noise thru the speakers when I scroll windows using my wheel mouse or if I scroll through menus or if I just drag a window around the desktop, if I stop all motion the noise goes away but I can still hear a tiny amount on static/white noise, if I begin movement again I can hear the RFI (that's what it sounds like), I first noticed the noise about a week ago after I'd been playing some mp3's on iTunes and left the volume up high by accident. Now the noise is bugging me as I don't recall hearing the noise before.

I can hear the noise as well if i use an Griffin iMic as the audio out with a pair of Sony Fontopia phones

Thinking it was something that I added to the G4 I took out all the PCI cards and just left the CPU upgrade in and the SATA card and AGP card but it still did it.

Having conducted some more tests from what I can tell it something related to Tiger 10.4.X & My Digital Audio G4, I have a firewire drive with Panther 10.3.7 on it when I boot off that I can't hear the noise at all.

Thinking it was something wrong with my Tiger install I cloned my iBook G4 1.33 (10.4.2) onto the G4 in target disk mode and it still makes the noise. The iBook G4 is noiseless.

G4 Digital Audio w/Giga Designs Dual G4/1.2GHz over clocked to 1.4GHz, 768MB ram, 320GB SATA Raid 0 (2 x 160gb Maxtor DM+9), Firmtek 1S2 SATA Card, ATI Radeon 9800Pro, Alchemy DVR, GeeThree Sweet MultiPort
I'm not sure but I don't think the noise was there under 10.4.1 or .2
I'd welcome any thoughts opinions on this as I have no idea what's wrong
Thanks, Mick B.
(I asked if disabling the Sound Prefs setting for "Play user inferface sounds" changed the behavior-Mike)
I tried to disable "play user interface sound effects" but it did not make any difference.
I've also done an OF nv-ram reset as well and set-defaults
I logged in as root and removed all the audio kexts and then booted again and sure enough I had no audio at all, but I did have silence. I then put all the Panther audio kexts in the Extensions folder of Tiger and booted but still had the same audio problem.
I'm at a bit of a loss with this one.

(I mentioned several other readers also reported the problem)
Well I thought something had gone wrong with the logic board or something, I was using Tiger from day 1 and did not recall hearing the noise, I have a hunch that something happened in the 10.4.2 upgrade.

The strange thing is that you can hear the sound on the iMic, which AFAIK is a totally separate audio system and DA-AD converter, assuming my understanding is correct, all the signals inside the G4 regarding audio are in the digital domain, and in the instance on the iMic they stay that way until the hit the amp I.C inside the iMic and then get turned into an analog signal for an Amplifier.

It sounds like a crackling noise (like a dirty vinyl record). Tonight I'm going to do a clean install of Tiger on another drive in the machine and see what happens then, if it's OK, I'll goto 10.4.1 and try that on so on and see if it's 10.4.2 like I think it is.
Just to clarify, the problem can also be heard thru a Griffin iMic when using it as the audio output, it's exactly the same noise as off the G4's audio. When using the G4 internal audio I'm using headphone socket of the G4 connected to a pair of Creative Inspire T2900 speakers."

My first thought was that it's PS related, but he said it doesn't happen in 10.3.x. If any other reader notices this let me know your system config.

Reader Reports: (most recent info first)

(added 9/7/2005)
"Hi Mike, (Unlike some others here) I've had this happen with my Sawtooth G4 tower, even pre-Tiger. The solution that worked for me was simply to leave my tape deck plugged into the mic/line-in jack at all times. Just having something plugged in, even if it wasn't turned on, would cause that annoying noise to cease.
Best, Jordan "

If any other reader notices that helps, let me know.

(added 9/7/2005)
"I noticed this in my G5/DP1.8 Rev A with a FireWire 400 card at home too. I used to have the same issue with a Quicksilver/DP 1GHz; but the problem went away after adding a PCI audio card.
-Frederik "

Not sure what PCI audio card he had but some users of M-Audio's PCI cards (Revolutin 5.1 and 7.1, etc.) have mentioned noise and other issues at times on the reports page here on their cards. There's also a page of M-audio USB transit reports here. (See the Audio topics page.)

(added 9/7/2005)
"I have a G4 Powerbook 1.33 (15") running Tiger.
I have the same noise when I use my scroll wheel with a Microsoft Mouse.
The noise is also there when I use the touchpad.
It is irritating to hear that noise..
I first started noticing it when recently.
I do NOT have the noise with my G5 2.0 DP.
Larry M.
BlueWeb Designs "

(added 9/7/2005)
"I've seen this on Panther on 2 Quicksilver machines. I'm guessing logic board.
-Ken "

But the reader said it didn't happen in 10.3.x. If it was logic board related I'd expect it to happen in any OS version.

(added 9/7/2005)
"Hi Mike, I get the same problem as Mick B (I think Mick is a mate of mine, living over in Tehran or somewhere? used to live near me!!)
Anyway, i have a 1.4GB Mac mini, about 4 weeks old, and I get the same whining noise as described. I was wondering about it this morning, then I saw this post. I'll try turning my speakers down and see if it disappears tonight!
(Jake later wrote in reply to a report from a reader that said it was connector related-Mike)
well, not an issue for me, as I have no speakers or headphones plugged in.
cheers, Jake S.
Creative Director "

(added 9/7/2005)
"I had this once. The problem was solved when I plugged the mini-jack correctly in the G4. The problem seems to be that the mini-jack is not completely connected and the faulty ground is making this problem happen.
Pete "

Since he said using a 10.3.x boot disk (with the same system setup) didn't have the problem it doesn't sound like a plug/jack issue though.

(added 9/7/2005)
"Got the same issue. Noticed it a while ago when my sound output was extreme high (the amplifier)
The sound out volume in System Preferences in OS X doesn't influence the sound level when scrolling.
My setup
G4 Quicksilver 867 Mhz
Nothing Special on my setup
-Willem
(I asked if he was running 10.4.2.-Mike)
yep 10.4.2 in 10.3 no issue "

(added 9/7/2005)
"Hey Mike, I read the report of the user that had noise when scrolling in Tiger and I too have noticed the same thing. It is very faint so you will have to max your speakers volume. But I only get it when scrolling with the scroll bar and not when scrolling with my mouse scroll wheel. I checked and it makes no difference wether "Play user inferface sounds" is on or off. Also I looked into it and the sound is coming from the speakers for sure and not the computer itself. My speakers are self powered with a very small consumer amp. Also of note; the sound does not occur when my iBook is connected directly to the same speakers and amp. I also noticed as I tuned the volume of my amp up the sound gets louder and when turned down the sound gets softer.

My setup is:
Dual 2.5GHz powermac G5, 4 GB RAM
Radeon 9600XT
160 GB and 250 GB SATA HDs. 200 GB PATA HD Shared with the Superdrive
No PCI Cards
-Chris V. "

I asked if he was running 10.4.2 and if he noticed it with older OS versions. (Most other G5 owner replies to the post just mentioned the G5 PS squealing/chirping issue fixed by disabling NAP mode.)

(added 9/7/2005)
"I have spoken with Apple about this issue - and they've asked me to take it in...

I have a Powerbook 15" Al, and have noticed this effect the whole time I've owned it. Almost like a processing noise and is intermittently bad when doing things like moving windows, or even the cursor....when nothing is being done by me there is an audible hiss...like the default no processing noise.

However I have a feeling only very few people would be able to discern this subtle very high pitched audio.

Just didn't want your other reader to think it was just them....and btw it hasn't just happened w/ Tiger either!
Sincerely, Jules "

(added 9/7/2005)
"Hi, Mike. I have a Quicksilver 867 that I recently upgraded with a Giga Designs Dual 1.8 GHz upgrade card, as well as Tiger. I don't hear the constant static that Mick reported, but I do hear noise during CPU intensive activity. Specifically, I hear sharp snapping sounds averaging once every few seconds, very irregularly (sometimes occuring two or three in quick succession), when I do something processor intensive at the same time that I play a sound file, such as an mp3. The sounds do not occur when I am not playing a sound file, and they also do not totally go away if the processor is nearly idle, but they occur with lower frequency. It's not noticeable to be particularly annoying in iTunes, because I have the iTunes play volume set up to its maximum, so the music comes out with the same volume as the snaps. However, it becomes very annoying when playing DVDs, because the DVD audio tends to be very soft and I need to crank up the computer's volume to hear it. This amplifies the snapping sounds until they are distracting.

I believe this is a problem relating to the CPU upgrade, not to Tiger. (At first I wondered about that, however some readers with stock/original CPUs also mentioned it-Mike) At one point I had to return the CPU upgrade for replacement because it was unstable. I went back to the stock processor for a week or so and noticed no noises during this time, even though I was still running Tiger. The noise seems reminiscent of RF caused by static discharge, possibly in the computer's power supply. I've heard similar noises coming from my powered speakers when, for example, a nearby refrigerator switches off, but these noises seem to be more like "pop"s instead of "snap"s like I'm hearing.

It would be nice if Giga had a fix for this problem, but I don't think I'd give up the processor upgrade for another week to fix it.

By the way, the rest of my config is as follows: 1.5 GB RAM (also recently upgraded), retail Radeon 8500, Adaptec 2930CU SCSI card (unused), NEC ND-3500A DVD-RW drive, an IBM Deskstar 60 and a Seagate Barracuda ATA IV drive (both 60 GB).
Aaron R.
(I asked if he was running 10.4.2 and if he noticed this in previous OS versions.-Mike)
... Yes, I'm running 10.4.2. I haven't yet checked with an older version of the operating system, though I still have 10.3.9 installed on my other hard drive. I need to get to class (grad school), but I can check this afternoon if you'd like
The sounds I hear are emitted through the headphone jack, not from the case. I never use the internal speaker, so I don't know if that is affected. It's interesting to hear that other users have had this problem or a similar one, but I had been using my computer for almost four years with no such symptoms and it started as soon as I upgraded my processor. Unfortunate. Maybe the power supplies just can't keep up with the increased power demands (even though these are 7447 G4s). "

(added 9/7/2005)
"Mike, I have a Digital Audio G4 that I have upgraded with a Giga Designs Dual G4 1.33 Ghz processor. I already had tiger installed at the time so I can't tell you how it would have been like under panther. Mine booted up and functioned without any problems. However, I did notice a low volume high frequency sound that came through my speakers when the system was quiet. I could not hear it if there are sound coming through my speakers.
At first, I thought I was hearing things, but even my 5 year old can hear it. I do not have any PCI cards attached and have 1.5 gigs of memory. I think it is PS related too, but since my system works, I have not done much about it. I contacted Giga support and they said that they have not heard anything like this. They asked for my system configuration. I have not provided them with that information because I am kind of lazy and my system works. They ask for how the voltage jumpers were set, but I did not change any of the settings since I got the upgrade. Thanks for a great site.
Raymond "

(added 9/7/2005)
"I have the same problem on my digital audio. It has been going on since I upgraded to Tiger. I get a low hum in my speakers. It did not happen under 10.3.

My digital audio config is a GigaDesigns 1.2GHz running at 1.33GHz, Radeon 9600Pro, 1GB RAM, and a WD 100MB ATA drive running off the built in ATA channel. The only added card is a generic USB 2.0 card.
-Madison H. "

(added 9/7/2005)
"I have noticed the same noise in my (June 2004) Dual 2.0 Powermac. I am using a new 20Ó ACD. With the exception of an extra 4 GB of ram from OWC, the machine is completely stock. I had thought it sounded like the hard drive ticking. It is very faint but distinct to scrolling in or moving a window around. Let me know if you have any specific questions.
-Troy "

I asked to make sure this wasn't the G5 PS noise (chirping/squealing) issue.

(added 9/7/2005)
"I've also heard these noises through the speakers.. not very loud but still annoying. Dual 2.5 gig G5.
-Chris N. "

(added 9/7/2005)
"I noticed a noise like this with my MDD dual 1.25 when trying chud tools to lower cpu temp. (I assume he means enabling NAP mode to lower MDD Dual CPU temperatures, as mentioned in an older article here on the systems page. Disabling it on a G5 stops the PS chirping/squealing noises usually. Many Dual MDD owners originally reported problems enabling NAP mode although Tiger seems to have helped that. Later versions of CHUD (v4) don't show the option for MDD systems, but v3.5.2 still works in tiger readers said in past reports here.-Mike) when the screen saver came on it was noise present. I never tried chud tools in 10.3 so I cant say if it was present then or not. I just tested it again and don't hear the noise in menus but its there when an .qtz screen saver is active.

On a side note does anyone know a way to eliminate a buzzing sound my system eminates when playing a guitar through the computer while using distortion for the guitar. I use garage band and guitar rig applications on the mac. It is also present when I use distortion FX pre going into the mac. (I don't know about that but if anyone has a tip let me know-Mike)

My setup
MDD G4 dual 1.25
120 gig HD
1 gig RAM
Radeon 9600 had a Radeon 9000 stock
Cheap after market USB 2 Firewire 400 PCI card
Griffin Technology ProSpeaker Breakout Cable
Power supply and main fan mod. Power supply fans lowered voltage to slow fans to half speed
-Tom M. "

Not sure I'd want to slow the PS fans that much (might affect long-term reliability of the supply).

(added 9/7/2005)
"Hi Mike, Just a note to confirm Mick B's audio noise problem when scrolling. I have a G4 Dual 1.25GHz (FW800) machine which I erased and installed Tiger onto (10.4.2 now). I had a set of Behringer Studio Monitors plugged into the standard line out and could hear a little kinda chirping noise (hard to describe) when scrolling in Safari and iTunes. Not using any wireless peripherals that could cause interference, and it only seemed to happen when scrolling with my wired Logitech mouse....weird!!
Regards, Craig
(I asked if the noise was on the audio output (and not a PS chirp).-Mike)
Chirp was probably not the best description on my part!! but its definitely from the audio line out and not the PS. "