7 Replies Latest reply: Nov 7, 2010 11:24 PM by Mitch 751
Lathe Level 1 Level 1
This is a hail mary...

It's a saga but here is the sum up. I have a new production studio. I set it up so that I can run audio/video in another room for dallies/proofing etc. The receiver in that room is a Yamaha RX-V665. I have an optical audio cable coming out of the Mac Pro and into the receiver. Only problem is...no audio comes out of the optical audio.

The receiver plays fine when a PS3 is plugged into the same jack.

Six months ago I called Yamaha about it..they troubleshot it..looks fine...sent me to Apple.
Apple was great about it...they escalated it..even sent a tech to my studio that replaced the logic board. All the while Apple said "...it should just work"

Nothing changed...I gave up.

I decided to try again today. It was an exact replay of six months ago...nobody can figure out why it wont work. Apple suggested I disassemble the studio and take it to the Apple Store for troubleshooting.

I'm out of ideas.

Dual Quad Core 3.2 14GB, Mac OS X (10.6.4)
  • Tom Nelson1 Level 4 Level 4
    I've used the optical out from my Mac Pro to feed an older Yamaha receiver. Aside from having to select the optical output in the Sound preference pane, it just works.

    I'd suggest you do a bit of troubleshooting, find some other piece of gear thats got an optical input and try connecting your Mac Pro to it. If that works, well then you need to look at the Yamaha. If it doesn't you need to trace back to the Mac Pro.

    Good optical cable?

    Using any adapters?

    Have the cable plugged into the optical output and not the optical input?

    The other thing you can do is see if you can locate another Mac and see if it will drive the Yammy without any problems.


    And good luck!
  • Lathe Level 1 Level 1
    Thanks for the feedback.

    It is very possible that I'm making a fundamental mistake here. Perhaps I misunderstand what the built-in digital output port does.

    For instance:

    Can I use the built-in digital output port for everything...just as I would the analog port? (sys sounds, iTunes...Safari..etc)

    When I look at the "Audio Devices" window and select built-in digital output...the configure speakers option only gives me stereo as an option. All the other speaker configurations are grayed out.

    I'm pretty sure this is some kind of core audio conflict...are silly software setting...but I can't figure it out. As for your tips...i'll have to see if I can figure out a way of trying some of them.

  • Tom Nelson1 Level 4 Level 4
    Hi Lathe,

    Hmmm, maybe were on to something. You mentioned that when you look at "Audio Devices" window, and that got me thinking. You may be using the wrong interface to control how audio is fed out of your Mac.

    Audio Devices is the window used for setting up Audio/Midi devices. For instance you can use the Audio Devices window to set the bit rate and channel assignments for the various audio or midi i/o on the Mac. But that only configures the internal hardware. It does not control which audio or midi ports are actually used.

    To get your Macs audio to be delivered though the optical output, try the following:

    Open System preferences, either by clicking on the System Preferences Dock icon, of by selecting System Preferences from the Apple menu.

    In the System Preferences window, click the Sound preference pane.

    In the Sound pane window, click the tab labeled Output.

    In the list of devices, select the Optical Output.

    This should route audio from your Mac, such as music from iTunes, to the Optical output and on to your yammy receiver.

    You can do the same for the various sound effects used by the system, by clicking the Sound Effects tab.

    Hope that helps.

  • Lathe Level 1 Level 1

    Sorry I should have been more clear. I do have the systems preference for optical out set correctly. However, I wouldn't be surprised if it is something silly like that.

    I'm open to the most fundamental feedback...no ego here I just want to get it working.

  • mac_user_007 Level 1 Level 1
    Hi Lathe,

    I'd recommend trying another piece of gear with that same cable using an optical out to the yamaha receiver. If that looks good, then it's definitely something on the mac side of things and maybe the below will help.

    Regarding this comment:
    "Can I use the built-in digital output port for everything...just as I would the analog port?"

    You technically should be able to use it for everything, but it's possible the Mac is outputting an incompatible digital signal to your receiver. Another test is using a movie from a DVD (or anything with digital tracks) that you can output with testing DTS and AC3 output to the receiver. It's possible your receiver supports some of the newer digital audio tracks as well, so those are worth a try as well.

    It should be plug and play with the MAC, but I've had issues with other equipment using digital out to receivers and dealt specifically with the source format not being correct. My workaround for that, which probably doesn't apply to this situation, was using a tool to encode all my audio to AC3.

    good luck.
  • PCET Level 1 Level 1
    Hi, Lathe,

    Have you worked out the digital output issues? I have the same problem and have been using the analog output on the Mac Pro to connect to my pre-Amp in the past. Unfortunately, the Mac Pro analog connection just started making irritating humming noise. I am, thus, looking to troubleshoot and for a new solution as well.

    Thanks for sharing.

  • Mitch 751 Level 6 Level 6
    Mac OS X
    irritating humming noise - can caused by poor audio cable, have you tried another one ?