Mac Mini 2009 weird optical out behavior

Discussion in 'Mac mini' started by jdryyz, May 11, 2009.

  1. jdryyz macrumors regular


    Jun 12, 2007
    I've noticed a couple of weird things happening with the optical audio output on my new 2009 Mac mini. The first thing I've noticed is that my receiver will stop displaying a PCM signal after a while (when no audio is present). It is as if there is a new energy saving feature to disable the optical audio when not in use. Sending an audio signal does not always wake it up, however, and I am forced to reboot to get audio working again.

    In more severe cases, the entire audio device acts as though it is missing. I cannot affect the audio out via the system preferences and the volume control on the menu bar goes missing! Rebooting again fixes the problem.

    With my late 2007 Mac Mini, my receiver always displayed a constant signal being received from the Mac regardless if audio is playing through or not. It never dropped off.

    Anyone else seeing this with their new Mac Mini?

    In addition to this problem, I am also having problems with Bluetooth devices not staying connected. I read this being reported elsewhere. Hopefully a firmware fix is on the way.
  2. GoCubsGo macrumors Nehalem


    Feb 19, 2005
    I'm interested to see what people say as well since I'm about to buy a Mac Mini to be used as a media center.
    But FWIW my cable box acts the same and usually takes a minute to wake the system (and sub).
  3. RemarkabLee macrumors 6502a

    Nov 14, 2007
    I recognise the symptom, the same happens with my Mac Pro and amp with regards to the Mac not outputting a constant digital stream, causing the amp to go into a 'sleep mode', therefore there is a delay when a sound is produced.

    A bit annoying but in my case, not a show stopper as the amp comes out of sleep when a sound is eventually sent from the Mac.

    Are you able to test with another amp? It is possible your amp is not happy about going into and coming out of sleep? My DVD player also has the same 'feature' in terms of shutting down the optical stream when not used so it's not Mac specific.

    Perhaps an optical repeater may solve this...
  4. jdryyz thread starter macrumors regular


    Jun 12, 2007
    Nope. Testing on another amp is not an option. Even if I had another amp, I'm sure the results would be the same as I am positive it is an issue with the Mac, not the receiver.

    I'm only speculating that the device is "going to sleep" by the way. It seems logical since this new Mac is being marketed as a "green" computer but I wonder how much energy is being saved by this. I'm thinking not very much. And, considering how other devices may react to this "sleep mode" (keep in mind, the computer itself is not asleep) I'm surprised Apple doesn't offer more control over it in the Energy Saver control panel.

    Having to reboot to "fix" this is just a tragedy. It is not a simple inconvenience.

  5. RemarkabLee macrumors 6502a

    Nov 14, 2007
    Sorry, having just re-read the 'severe cases' bit again, it's clear this is a Mac problem in terms of the device not working in some cases.

    I agree that optical out probably doesn't take much energy. Perhaps you there is a workaround, like sending a looped silence sample to run in the background? Not tried this myself and it's not an elegant solution, but that will stop the optical out from sleeping. As for the output device disappearing completely occasionally and bluetooth issues, I'm sure they will be fixed soon.

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