Converting SPDIF to Optical

Discussion in 'Beginners, General Questions' started by Andre M, Oct 15, 2003.

  1. Andre M

    Andre M Auditioning

    Joined:
    Oct 15, 2003
    Messages:
    8
    Likes Received:
    0
    My Digital Cable box has SPDIF Out(for digital audio). My Receiver has Optical In (for digital audio from what I understand), but no SPDIF or other digital In input. Is there a converter to be able to connect these two and if so is it worth the money? Currently my audio on Digital Cable is just via RCA cables (from cable box to receiver) and it sounds pretty good with all 5 speakers working. Is this 5.1 sound then? How can this be if I am not connected via the "Digital" connection.

    I already checked the FAQ and there is nothing about this.

    Also is TosLink the same as Optical?

    Thanks
     
  2. GrahamT

    GrahamT Supporting Actor

    Joined:
    Sep 13, 2003
    Messages:
    556
    Likes Received:
    0
    Welcome to the forum.
    The optical (yes also known as toslink) input on the receiver is for digital audio.
    I dont know what SPDIF is. When using RCA inputs and DPLII or Logic 7 for 5.1 and not stereo5 then you do have matrixed 5.1 surround as opposed to 5.1 discrete. The receiver uses a program to create a center and two surround channels. Then it routes the low frequencies to the sub for the .1 .
     
  3. Andre M

    Andre M Auditioning

    Joined:
    Oct 15, 2003
    Messages:
    8
    Likes Received:
    0
    SPDIF stands for Sony Phillips Digital Interface....perhaps this is only a Canadian thing (I have a Motorola DCT2000HT cable box through Shaw Cable).

    OK, I now understand how I'm getting 5.1 sound.....you are saying in essence it is an artificial 5.1 connection via my receiver. So it would seem as though I shouldn't worry about this further even though it is not a Digital connection, or should I try to make the digital connection work?
     
  4. Bob McElfresh

    Bob McElfresh Producer

    Joined:
    May 22, 1999
    Messages:
    5,182
    Likes Received:
    0
    SPDIF is the standard that covers both the optical and coaxial-digital connections from a DVD player.

    (Just like AC3 is the name of the technique that we all call Dolby Digital).

    I assume Andre is saying his CATV box has a Coaxial-Digital connection out, but he only has a spair optical input.

    Yes, there are converters available from places like www.partsexpress.com and even Radio Shack. And they typically work well.

    But - people who have tried to use the digital output have reported problems:

    - Sometimes the jack is present, but does not work (depends upon what options the CATV company choose to buy)

    - If the jack works, it only works for the "Digital" channels, usually the ones above 100. The digital feed goes silent for the analog channels. You now have to switch your receiver to handle the analog L/R feeds. Some receivers have a auto-detect feature that makes this automatic.

    Before you invest the $15 in a converter, call your CATV company and see if the digital output works for ALL channels. If so, then go for it.
     
  5. Andre M

    Andre M Auditioning

    Joined:
    Oct 15, 2003
    Messages:
    8
    Likes Received:
    0
    Thanks Bob, that's exactly my problem. After reading these forums today at work it's tempting just to return my system and step up a notch. I've learned a tonne in the last few days setting everything up and reading here.
     
  6. BenSC

    BenSC Stunt Coordinator

    Joined:
    Jun 19, 2003
    Messages:
    190
    Likes Received:
    0
    That being said.. I had digital cable through Time Warner and used the Digital-Coax connection just fine.
     
  7. Andre M

    Andre M Auditioning

    Joined:
    Oct 15, 2003
    Messages:
    8
    Likes Received:
    0
    One other question. The cable people said that yes not all are digital. Therefore I'll need to keep my analog connection in my receivers TV input for those channels and hook up the digital connection as well. My receiver wouldn't automatically switch

    So where channels are Analog I would select TV as my input. Now where channels are broadcast in 5.1 or 2.0 how would my receiver know to use the digital input rather than analog. I don't have the option to select this on my receiver - only TV, Aux, and VCR inputs and of course a DVD/CD option.

    I read that digital is either on or off, so if the cable box is sending a digital signal than my receiver should broadcast this and I wouldn't have to select anything on my receiver. Basically how will my receiver know to play the digital sound from my cable box? Would I select the DVD/CD option? Obviously TV, Aux, or VCR would not be appropriate.
     
  8. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,100
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
    Andre,

    To clear things up a little, “digital” isn’t necessarily 5.1. “Digital” simply refers to the delivery of the signal to the receiver.

    Dolby Digital 5.1 is a specially encoded, compressed digital signal that requires a decoder in the receiver separate and convert the signal to multi-channel audio.

    Digital 2.0 and regular two-channel stereo are essentially the same thing. The only difference is that the former is converted to analog at the receiver, while the latter is converted in the source component (in the case of CD and DVD players etc.). As far as what you will hear through the speakers, they both sound the same.

    I don’t have digital cable, but as far as I know the only programming available in 5.1 is some of the premium movie channels. As far as I know, no cable channels (A&E, TLC, etc.) are providing any 5.1 programming at this time. So any channels other than premium movie channels, if the delivery is digital, it will be only 2.0.

    As far as your connections go, how their done will depend on your HTIB’s capabilities. If it will do automatic switching between analog and digital signals, then you can connect both the digital and analog (RCA) sends from your cable box to the CD/DVD input. This way, whenever you tune a channel that does hot have a digital feed, the receiver will switch to analog:

     

Share This Page