CPU noise through AC mains

[skylab001]

OK so I have this high pitched whine that I get through my system, seems to be in the 9-14khz range and it is really annoying. Yes it's faint but peircing when your in front on the monitors all day long. After going through my what I think are well organized cables I have realized that it seems to be my 002R is picking up line noise from my CPU. Anyone else ever have this problem? When I shut off my CPU it goes away. The problem is I can't record without the CPU. I have the PT hooked up to my Furman power conditioner, however it is the bottom of the line model. Does the filtration differ on these units. Any advice would be helpful.

Thanks!

[kite]

What Mac do you run - I had a similar problem awhile back, with my old G4 450 -it turned out to be the fan on the PSU in the Mac. A new PSU solved the problem -the fan had gone off centre, worn bearing or something.

Alternatively, are you running the inputs to you 002 balanced or unbalanced -could be noise getting in that way ?

Just guesses though!

[Kling3]

I had the same problem when I moved from the 001 to 002r. Be sure to use quality "balanced" outs to your power amp or active monitors. This eliminated my problem. If that doesn't work, bypass your Furman and see what happens. I have had issues with standard computer type power strips. This being said, I'm using the Furman RP-8 with no problems. Good luck.

[mersisblue]

I also had this problem

first I had a repair done by digi

then it was still there so I got new

cables for my monitors and bang

it worked . I went with monster .

one thing you can try

Is the noise in your head phone outs ?

If no then It sounds like a cable / grounding issue maybe

[skylab001]

I've got balanced cables all the way through my studio on anything that allows for balanced and that includes the my monitors. I have pretty much pinned the whine to my CPU and somehow the noise is creeping through the power connections. It seems to be most likely the fan, because when I have everything off except for my monitors, and then start up my CPU I can here the whine kick in when the fan starts. I have a G4 400, so maybe I have a similiar problem with my fan.

Kite you had to replace the entire PSU for the CPU? or just the fan? Was it expensive?

[kite]

Hi,
yes, I had my local dealer(Cancom) replace the PSU, on a Part exchange deal, and from memory, it cost me about £60 sterling. They said that they were unable to replace just the fan, as Apple would not supply this on its own. Maybe a replacement fan could be found from Maplin or a similar PC replacement, but I needed my Mac back fast, so never pursued this route.
The PSU is not too difficult to remove from my G4 450, but getting into the PSU itself might well be tricky.

Good Luck anyhow.