High-pitch With Firewire Options

[iShawn]

The problem I am having is noise that the computer is making when the firewire is plugged into it with the Firepod. When the power cord isn't plugged into the computer, the noise ceases but when I plug the firepod into it in any combination of the firewire outs, etc I get this noise. This noise stops for a second when I click on something or other wierd actions like that.

Anyone have a solution?

[macyu]

Yeah I had this problem too. A small discussion was on apple's site as well. A rumor I heard was that it was a 10.3.6 problem.. I'm not sure, but it does seem like a power-manager issues involving the inverter, since when I turn the Energy savings for the CPU to 'low' mode, it disappears. Have you tried it with 10.3.7? I'm on the road right now, and don't have the firepod, so I haven't been able to test it out. I already reported the problem to Apple, and Presonus, but haven't got any answers. BTW, I'm using the 1.25ghz powerbook with the Firepod. Another thing I haven't tried yet is another firewire cable. I have heard that people had problems with the Protools 002 and a bad firewire cable.

[arvidtp]

I have had this same kind of high-pitch sound problem that disappears when clicking and stuff (coming from the computer, not the audio interface) on and off since 10.2.7 (I am now using 10.3.6 on my powerbook 1.25 GHz 15") when I have my USB Mbox plugged in. I haven't noticed it recently though. I did change the USB cable i was using for the Mbox (as the one that came with it was loose and kept disconnecting), so that may be it, but no idea.

Awful about those Tsunamis in Sumatra and Sri Lanka!

[iShawn]

I bought a Belkin Firewire cable to replace the problem and have become somewhat satisfied. The sound isn't gone, but it seems much quieter and someone liveable-with. So... I guess buyer beware of that... unless it's another option I haven't tried yet.

[iShawn]

I have tried to get ah hold of Presonus for any input but haven't had a response back yet. I think tomorrow I'm going to go to the apple store with the pbook and firepod and try out another power cord to see if that might be the problem. That really sticks out in my mind because when the power cord is unplugged from the computer, the noise ceases precisely without any delay... and whenever any sort of spike in power (like the computer is thinking or whatever) there is a silence such as, for instance; when Cubase is starting up... I get nothing, and then the noise again.

This is annoying as hell... but I have messed around on it.. and will have a better review and be a better reviewer of the Firepod when this little mishap gets taken care of.

[fictionmusic]

Hi guys

You may be experiencing the dreaded nap whine. My computer had the same thing: a high pitched whine that would change when I scrolled and moused over different things. The problem is caused by grounding apparently (or so I have heard) and how the mac uses the power to cycle the processors (again I have heard this as an explanation)
At any rate the fix is to download and install the CHUD tools. Once installed there is a window that comes up and it has a checkbox that says nap. Click it to remove the arrow and that should get rid of the whine. I have done it since Oct 2003 and have experienced no ill results although the fans sometimes kick in for a bit when I uncheck it.

go to this page and about 1/2 way down you'll see the link to download CHUD


http://developer.apple.com/tools/performance/

[macyu]

Cool find. I googled it - lo and behold, there's been other reports, even without the Firepod where the powerbook (and even powermacs!) start whining. However, one downside for us laptop users: "However, I'd recommend that you leave Napping enabled (to reduce heat output and increase battery life), so leave it in the default state." (cited from Macintouch) I'll see if this works first of all, and how hard it would be to switch from nap mode to non-nap mode and vice-versa (like for just a recording/mix session).

[iShawn]

Let us know if that does work out for you though... however this is just a treatment. In essence, we want a cure... and just like more humans, I want my stuff to work. I wrote a plea to Mac for some answers... we'll see if that actually gets answered though... hmm

[iShawn]

Well... I'm impatient... and I tried it myself. Wow I must say the whine is gone. How in the hell did that work!!?!?!??!!

I still hope there is some way Apple will fix this for next time though!

This isn't going to have any damaging lasting effect now is it?

I don't hear my fan come on at all.

The preferences in it can put an icon on the menu bar which you can open the preferences and switch back and forth for ease of use or you can go into system preferences and it puts it under the "other" category with a picture of the powerpc chip.

I'll put this guy's post on the apple forum for others to see as well...

Thanks

[fictionmusic]

Her is the explanation I got from a poster on yahoo LUG group last year.
It was posted by a musician named Rob Yale and here is his take on it

ÈWhen you turn off the Nap setting in CHUD tools, you disable processor
cycling. Because Apple put a cheap transformer coil in the power
supply, the processor cycling induces RF which propagates throughout
the G5. My guess (and backed by a friend of mine, former electronics pro and
now IT...) is that (cheap) filter coils in the PSU start to vibrate,
similar to loudspeaker coils, when the CPUs switch between high and
low power use, which can happen very often at 2 GHz clock cycle. Since
disabling CPU napping results in the CPUs consuming a fairly constant
current, the vibrations stop (the magnetic fields in the coils remain
constant).È

I have used CHUD tools for over a year now (in my menubar as recommended by iShawn) and have had no ill effects. My system has been rock solid and totally quiet. (I have it on 24 hours a day pretty well 7 days a week, in a busy producton suite)