SPDIF (COAX) Output, not supported?

Discussion in 'MacBook Pro' started by Fujikon, Apr 24, 2010.

  1. Fujikon macrumors member

    Jun 17, 2007
    My PC has a digital out jack that uses a mini plug (SPDIF) converted to a single RCA jack (COAX). When I tried this on the MBP (latest 13 inch), I don't get any sound at all. The sound manager under settings detects the connection as headphone. Is this type of connection not supported at all? Do I need to go via TOSLINK to get digital sound?
  2. Mac Questions macrumors member

    Feb 17, 2010
    I'm pretty sure your Mac should support it, don't quote me on it though.
  3. paintballswimgu macrumors 6502

    Feb 13, 2010
    I actually had this same problem on my new i5 mbp. I found out that they still support TOSLINK through the audio jack. The cable just has to be pushed in really far in order to get it to trigger. Depending on which cable you are using you might not be able to get it to work. I'm using the monoprice cable. It works, but you have to push it in extra far to get it to work.
  4. drayon macrumors 6502

    Aug 20, 2007
    Impossible or you are confused.

    SPDIF can use Coaxial copper cable with an RCA plug to send data electrically with electrons.

    SPDIF can also be Fibre Optic sending digital data optically with photons.

    TOSLINK is just a connector on a Fibre optical cable can be either a black 3.5mm plug which connects to the headphone out on the MBP or a TOSLINK connector variant usually will have the normal TOSLINK optical plug on the other end or another TOSLINK plug this will connect to the Optical Output (or input) on your PC.

    Apple's audio output is 3.5mm TOSLINK it also supports optical digital audip on the digital cable and analog audio over a 3.5mm mini jack cable.

    You cannot and there is no cable that converts optical/electrical ie RCA Coax/TOSLINK. IOW you cannot have a Coax RCA on one end and Optical connector on the other end, you'd need a conversion box to do this.

    this is what it looks like



    If you have an optical cable SPDIF on both ends you can get a plug adapter to get the TOSLINK 3.5mm

  5. Fujikon thread starter macrumors member

    Jun 17, 2007
    Thank you all so far.

    Drayon, so to be clear, the MBP does not support SPDIF via copper cable with RCA plug?
  6. alphaod macrumors Core


    Feb 9, 2008
  7. drayon macrumors 6502

    Aug 20, 2007
    Correct. S/PDIF on the MBP, in fact all Macintosh computers runs only on Fibre Optical cable.

    To support Coax S/PDIF the computer or other audio device must have a dedicated RCA S/PDIF connector. Many A/V receivers will have two Digital S/PDIF interfaces, RCA (coax) and TOSLINK (optical) because some devices may have only Optical or Coax Digital. Coax must be RCA on both ends and the Fibre can never have RCA, only the TOSLINK connector or the 3.5mm TOSLINK.

    Here is a pic of the two Digital S/PDIF interfaces


    The left is RCA (Coax) the right is TOSLINK (optical)


    Hope it helps. Also there is no need to buy the very expensive Optical TOSLINK/TOSLINK 3.5mm cables that some places try to extort consumers. Just the thin cheapest cable is fine. Also NEVER bend or fold the cable this will break it.

    These are the cables you need TOSLINK to TOSLINK 3.5mm (mini) connect the mini jack looking connector to the MBP I/O and the other end squared connector to the PC's Optical I/O this wont work if the PC has only RCA in that case you need the format convertor alphaod posted above


  8. Fujikon thread starter macrumors member

    Jun 17, 2007
    Drayon thank you for the thorough response. I might have to get what alphaod posted.
  9. drayon macrumors 6502

    Aug 20, 2007
    Do you know the model of the PC motherboard? or have a pic of the I/O back plate of the PC?
  10. Fujikon thread starter macrumors member

    Jun 17, 2007
    Oh, it's my receiver that I am trying to connect it to. The receiver has the RCA jack.

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