Problem with Macbook Optical Out

Discussion in 'Digital Sources' started by oteoi, Jul 30, 2018.

  1. oteoi

    oteoi New Member

    Messages:
    20
    Hi all,

    I'm trying to run a Macbook into a Denon DM-41 receiver via Optical (mini-Toslink on the Macbook end to Toslink on the receiver). I have tried playing music from iTunes, VLC, Youtube, Spotify and others, but I always just get silence and a message on the Denon that reads: "Signal Unlock".

    In the Denon manual, it says: "'SIGNAL UNLOCK' is displayed when audio signals that are not supported by this unit are input, or the sampling frequency cannot be detected."

    The Macbook recognises an optical connection has been made and is set to digital output, and I've gone into the audio settings and tried every sample rate available. Given the Denon says that it supports 32/44.1/48/88.2/96/176.4/192 kHz at 16/24 bits, I am stumped as to why it isn't working.

    I've now tried two separate optical cables but to no avail.

    I presume it is a problem at the Macbook end, but any ideas as to how to solve this would be much appreciated.

    Thanks
     

     

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  2. awillia6

    awillia6 Super Member

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    1,126
    Does your Denon receiver work with a different optical source? Does your MB's optical out work with a different receiver?
     
  3. oteoi

    oteoi New Member

    Messages:
    20
    No way of checking the latter, as the Denon is the only receiver I have with optical inputs. I will move things around and try the television optical out into the Denon tomorrow, although my suspicion is that the solution is probably somewhere in OSX, and hopefully quite simple.
     
  4. awillia6

    awillia6 Super Member

    Messages:
    1,126
    Surely you have a friend or co-worker with an optically-equipped receiver to which you could take and connect your MB for test purposes. In a pinch, just grab your MB and an optical cable and head into a store that carries audio equipment. Nobody should mind a temporary optical connection since there's no danger of shorts, power surges, etc. Good luck.
     
  5. cpt_paranoia

    cpt_paranoia Active Member

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    498
    Can you see a red glow flow from both the MB port and the other end of the TOSlink cable?
     
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  6. oteoi

    oteoi New Member

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    20
    I've tested the receiver with the TV optical output today and all is working fine on that end. I just plugged it in and out came the audio, so it would seem that the receiver isn't faulty. In my current location, there really isn't anyway of testing the Macbook with another receiver, so for now we're just going to have to work on the assumption that its hardware is fine and that it's most likely a software issue of some kind.

    cpt_paranoia: what should be glowing? The ports?
     

     

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  7. cpt_paranoia

    cpt_paranoia Active Member

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    498
    Yes; TOSlink uses a visible red emitter, so you should see a red glow from the mini-TOSlink port on the MB, and from the free end of the TOSlink cable when plugged into a source.

    Since your receiver is working with the TV, clearly, the cable and receiver are okay; look at the cable plugged in to the TV to see what it should look like..

    You may also need to make sure the MB really does have its TOSlink output enabled.
     
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  8. awillia6

    awillia6 Super Member

    Messages:
    1,126
    Also, the TV's optical out was presumably a full-sized TOSlink port instead of the mini port on the MB. It's possible that the mini adapter used to convert a standard optical cable for use with the MB has a problem and won't pass the optical signal (perhaps a protective cap is stuck in it). The visual check for a BRIGHT red optical signal (and comparing the TV's visible output to the MB's) is a good idea.
     
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  9. oteoi

    oteoi New Member

    Messages:
    20
    I have two separate cables that I've trialled: one mini-Toslink to Toslink and another Toslink to Toslink with a mini-Toslink adapter on the end that goes into the Macbook (it was this cable, without the adaptor, that worked in the TV to receiver trial). I'll give it another go this evening and see if the red light is visible. Thanks
     
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  10. oteoi

    oteoi New Member

    Messages:
    20
    The plot thickens. I plugged one end of the Toslink cable into the TV and turned it on and, as advised, a red light came on at the other end.

    I then did the same with the Macbook and played a song through iTunes. Bingo! Both cables I have displayed a red light on the other end as the song was playing.

    So it seems that the cable is definitely sending a signal of some kind from the Macbook to the receiver. For some reason, the receiver doesn't recognise it but does recognise the TV output.

    Any ideas?
     
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  11. petehall347

    petehall347 the brandy coffee man Subscriber

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    can you try a different format that the receiver likes ?
     

     

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  12. FONSguy

    FONSguy Super Member

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    Is the OS up to date on your MB? You may have to download specs on both devices to find out what the deal is. Is the volume all he way down on the MB for some reason?
     
  13. oteoi

    oteoi New Member

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    20
    I've cycled through all of the sample and bit rates that the Macbook will output at, all of which the receiver should be able to receive. Per the manual, it supports 32/44.1/48/88.2/96/176.4/192 kHz at 16/24 bits. I've tried each and every one of those without success.
     
  14. oteoi

    oteoi New Member

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    20
    Yep, all up to date. The Macbook outputs digital as a digital line out, so there is no volume control. The Macbook lets you choose the sample and bit rates it outputs at and matching those to the ones that the Denon manual says its accepts still doesn't produce any sound.
     
  15. petehall347

    petehall347 the brandy coffee man Subscriber

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    Location:
    uk.. the middle bit
    page 62 ....
    Be sure to give files the extension “.MP3” or “.WMA”. Files with any other
    extensions or files with no extensions cannot be played.
    0 Mac OS X files assigned with filenames that begin with “._” are not music data and
    cannot be played back.
    0 In accordance with copyright laws, recordings you have made should only be used
    for your personal enjoyment and may not be used in other ways without
    permission of the copyright holder.
     
  16. oteoi

    oteoi New Member

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    20
    That relates to DATA CDs, not the digital inputs.
     

     

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  17. awillia6

    awillia6 Super Member

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    Does your MB have a spinner? If so, simply load a CD and listen to it through the MB's (analog) audio out jack using headphones or earbuds with a 3.5mm stereo plug. Then, once you're SURE you're getting audio output, switch from analog to digital by swapping in either optical cable (mini to standard optical port OR standard to standard plus mini adapter). Run the far end of the optical cable into your receiver set to the same input/mode as when it worked with your TV optical out. Good luck.
     
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  18. willyrover

    willyrover Super Member

    Messages:
    3,104
    Location:
    Hamilton
    I assume you're selecting these through Audio MIDI Setup on the MBP?

    What year is your MBP?


    Plugging the optical cable into the MPB automatically switches the output to Digital and the other end of the optical cable should be lit up red as long as something is playing. If nothing is playing, the light goes to sleep or something.

    Plugged In:
    Screen Shot 2018-07-31 at 3.00.53 PM.png



    Unplugged:
    Screen Shot 2018-07-31 at 3.01.54 PM.png
     
  19. oteoi

    oteoi New Member

    Messages:
    20
    The model is a Late 2013, Retina.

    Yeah, the output automatically switches to digital, and I've then been using Audio MIDI Setup to change the sample and bit rates to see if I could get any of them working. The one difference I do note in comparison to your screenshot is that when it is on digital, the 1 and 2 streams are both greyed out, without the ability to set the volume level.
     
  20. willyrover

    willyrover Super Member

    Messages:
    3,104
    Location:
    Hamilton
    Yah, if I collapse that frame and expand it again, they are also greyed out.

    Are you using a regular toslink cable with a mini-toslink adapter? or a toslink to mini-toslink cable?
     

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