Mac pro 2009 high-pitched noise with firewire interface

Discussion in 'Mac Pro' started by 5ibl1, Mar 21, 2016.

  1. 5ibl1 macrumors newbie

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    Mar 21, 2016
    #1
    Hello, I posted about the same thing also to the digital audio section but figured this might be a better place to find a solution to my problem.

    Recently I bought a used Mac pro '09 and I'm using my RME Fireface 400 with it. Everything is stable and working as it should except that every time I'm playing audio through the interface there's a high pitched tone ringing inside the computer. This ~8 kHz whistling is not loud but it's there all the time I'm playing something from the computer with or without the interface plugged to the speakers. I've tried changing the firewire cable and plugging the computer to another electrical socket and also unplugging everything else in case something was causing interference but nothing seems to affect this. There was also some unwanted noise (some kind of interference) coming from my speakers when using the interface bus-powered but with the power cable it's gone.

    I've been using the interface for several years mostly with a macbook pro and never had this kind of issue before. Apparently this has been quite a common thing especially some years ago with OS X 10.6.3. With this combination of hardware and El Capitan it's certainly back at least for me.

    There seems to be discussion related to this but I don't know if a solution exists. Has anyone else had the same kind of problem recently and hopefully found a way to fix it?

    I found a thread from last year about the same kind of problem where someone suggested to buy a firewire 400 PCIe card. Could this work for me? Now I'm using a firewire 6-pin to 9-pin cable.

    Thanks in advance
     
  2. Machines macrumors 6502

    Machines

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    #2
    Are you getting this interference with your interface connected to either the front or rear FW400 ports ? They are on separate circuits .
     
  3. 5ibl1 thread starter macrumors newbie

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    #3
    Yep, I'm getting the ringing from both ports.
     
  4. Machines macrumors 6502

    Machines

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    #4
    Are you using a line conditioner , out of curiosity ?
     
  5. 5ibl1 thread starter macrumors newbie

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    #5
    I'm not using one yet, but maybe I should.

    I should add that the interference is gone when there's no audio going through the interface even though it is powered connected to the computer and when there's even a short signal played – for example the basic OS X alert sound – the whistling occurs and then stops maybe half a second after the alert sound ends.
     
  6. Machines macrumors 6502

    Machines

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    #6
    If you are experiencing the interference since using OS X 10.11.x El Cap , perhaps you should load a copy of OS X 10.10.5 Yosemite on a spare drive and see if the problem persists . It would help to verify this as a hardware (Mac, Interface, AC mains outlet) issue .
     
  7. 5ibl1 thread starter macrumors newbie

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    #7
    The thing is that I got this computer with 10.11. installed as I thought it would be already reliable enough. I didn't have this problem with my old computer and 10.6.8. but with another computer and another version of OS X there's so many variables...

    I don't happen to have any spare drives lying around at the moment and can't download 10.10.5. from App store because I never did when it was the OS X to update to. You are definitely right about that helping to verify the issue, there's just some extra hassle included.
     
  8. Machines macrumors 6502

    Machines

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    #8
    It's a good idea to download an OS X version when it becomes first available (even if you don't plan to actually install it .) This places the OS X version in your app purchase list , hopefully , permanently .

    I'd also hesitate to use the latest OS X version , as it is still being updated . Best to use the last final OS X version . In this case, OS X 10.10.5 Yosemite .
     
  9. 5ibl1 thread starter macrumors newbie

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    #9
    I'll experiment with Yosemite as soon as I have time.

    I just noticed that when I connect the computer's optical audio output to my interface's optical input the whistling doesn't occur even when there's audio going through it. The audio interface is still connected to my computer with firewire and I can control it's internal mixer and matrix using RME's Totalmix. So it seems the interference is happening only when audio is going through firewire. The interference occurs when Logic X is open (doesn't have to be playing anything or have a project opened) and the Fireface is selected to be either the input or output device, or both of them.

    Could some factors be excluded because of this behavior?
     
  10. Machines macrumors 6502

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    #10
    Not certain . Maybe it's time to put in a bug report to Apple if it is a Logic issue . Have you tried using a different interface from a friend , to try to determine if the issue is a faulty FW port or a bug in Logic ?
     
  11. 5ibl1 thread starter macrumors newbie

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    #11
    I haven't tried yet with a different interface but I think I could borrow one and try tomorrow. I'm not sure if the issue is related to Logic because it's happening also when listening music from iTunes or Youtube etc. The difference is that with Logic the interference is continuous and doesn't require anything to be played through the device to occur.

    As I said before, there was something similar going on some years ago:
    http://forums.macrumors.com/threads...oblem-with-pro-audio-hardware-devices.866341/
     
  12. DPUser, Mar 22, 2016
    Last edited: Mar 22, 2016

    DPUser macrumors 6502a

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    #12
    I'd try changing the Firewire cable and lifting the AC ground on the interface.

    In my studio, I run the audio interface from a dedicated Firewire card. If you are otherwise unable to stop the ringing, you may want to try this approach.

    EDIT: Just reviewed the thread you referenced. PCIe Firewire card didn't seem to fix the problem for some back then. Have you tried a clean install of OS, maybe on a backup drive?
     
  13. 5ibl1, Mar 22, 2016
    Last edited: Mar 22, 2016

    5ibl1 thread starter macrumors newbie

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    #13
    DPUser, do you get ringing when your interface is connected to the computer's own firewire ports?

    edit: Or did you get at some point?

    2. edit: I got the computer a few weeks ago and it had a clean install of El Capitan then. After that I have upgraded the firmware (4,1 to 5,1) and processors, but I think the problem is hardly related to that as things went smoothly and everything else is working as it should.
     
  14. 5ibl1, Mar 22, 2016
    Last edited: Mar 22, 2016

    5ibl1 thread starter macrumors newbie

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    #14
    Okay, I borrowed a Focusrite interface and the same interference is happening with it so it's not the Fireface. Tomorrow I can probably test with OS X 10.10.5.

    Because of reading many different threads in different forums about something similar with OS X 10.6.3 I have an intuitive hunch that this could be related to a software issue. Back then Apple released an audio update to fix this kind of interference with Mac Pro 4,1 and firewire interfaces. I linked a thread a few posts back and here's another one:
    https://discussions.apple.com/thread/2339757?start=0&tstart=0

    I also noticed that the interference tone is ringing all the time when I have the OS X audio input preferences opened and the Fireface selected. The moment I click the audio output preference page the ringing stops.
     
  15. Machines macrumors 6502

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    #15
    Good , we are making progress . So, we can rule out the interface . Let's now determine if the issue is OS X 10.11.x EL Cap . It will be the source of the issue , if Yosemite works well .
     
  16. machenryr macrumors regular

    machenryr

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    Jan 25, 2016
    #16
    I use Metric Halo ULN-8s. FireWire. No noise. Just reporting
     
  17. 5ibl1 thread starter macrumors newbie

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    Mar 21, 2016
    #17
    I just tested with OS X 10.10.5 and the interference is still there. So it's not a software issue unless the same thing was going on already with Yosemite which would be kind of hard to believe.

    If the firewire ports are on separate circuits as was pointed before, and I'm getting interference from all the ports, I'd guess the problem is not exactly in the firewire ports either. Maybe it could be related to AC or grounding issues in this room or building after all?

    Thanks for the info, every piece in this puzzle counts.
     

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