Mac pro's firewire problem

[::XeS::]

I noticed this problem: with a firewire interface connected, the speakers (expecially the left one) produce a very annoying "electric" noise..and very sensible to what there is on the monitor (ex. page scrolling, bright pages, etc...) or also the mouse wheel scrolling is audible into the speakers.
It could be a ground loop, but in my opinion it's a firewire related problem.
My macbook pro had the same identical problem, solved disconnecting the external monitor.
I mean, it seems a combination of ground loop and firewire "sensibility"..
I read also that the same problem happened to several imac/macpro users.
I have the project to switch to rme adat pci card in the future so this will not be a problem anymore...but now it's a problem because the same noise goes into my amp if I have to do a reamp...
Anyone of you noticed the same problem?

 

[greyskull]

never noticed that myself.

 

[Skaldir]

What kind of speaker do you have? Do they have balanced connections? XLR? Then it shouldn't be there.
I had this problem with hearing the mouse in left speaker with my fireface and could solve it with a ground loop isolator Sinuslive GL-205.
You could also try to flip some powerplugs.

 

[::XeS::]

Yes XLR cables.
For example with my macbook pro, the proble disappears if I disconnect the external monitor or if I plug the monitor cable to another socket.
With the mac pro I tried to switch some positions but the problem is still here...the noise disappears only unplugging the firewire cable.
As I said, it's probably a ground loop problem accentuated by some kind of firewire interference

 

[GMFx]

I used to have that on my win computer back in the days. sickening.

 

[::XeS::]

As I read in another forum, raising and lowering the buffer size..the noise changes.
For example if I lower the buffer size at 128 in PT, the nouse is higher...if I raise the buffer at 2048, the noise is lower.
Pretty annoying...now I don't know if a power conditioner can solve the problem.

 

[JeffTD]

I had this issue on my mbp with an external monitor and the stock soundcard - make sure you're not running your DVI and XLR cables along the same path; them being too close could cause interference, although balanced cables generally prevents this in most cases.

 

[::XeS::]

No I found it's a ground loop problem. I tried to plug the speakers power chords in another socket and the noise disappeared at 90%.
So I suppose that a power conditioner + ups solution will solve completely the problem

 

[AudioGeekZine]

No I found it's a ground loop problem. I tried to plug the speakers power chords in another socket and the noise disappeared at 90%.
So I suppose that a power conditioner + ups solution will solve completely the problem

hopefully but good to have anyway.