Connect my new iMac to my stereo...which cable

Discussion in 'iMac' started by strider42, Aug 16, 2007.

  1. strider42 macrumors 65816


    Feb 1, 2002
    Just got my new iMac and I'd love to be able to connect it to my stereo system. I tried a simple 1/8" to RCA cable to connect it, but its a bit quiet and very staticy. I see that the line out jack is also a digital out jack, but I'm a bit confusde as to what kind of cable I actually require here. My stereo has a coaxial digital input I can utilize, but the iMac doesn't seem like it would have the same type of connector, even if is a digital output. Much appreciation for anyone who can clarify this for me. Thanks.
  2. nkawtg72 macrumors 6502

    Aug 16, 2007
    a 1/8" stereo to RCA should work. the thing to remember is that the output IS NOT A LINE LEVEL OUTPUT. this means you will also have to adjust the sound level on the Mac as well as your stereo to get optimum sound. it is recommended that you set the Macs sound to 2/3 or 3/4 full, then use the stereos sound control to get the desired level. if you set the Mac too high it can cause distortion in the signal that is being sent to the stereo. if this doesn't make sense, imagine a set of headphones. if plugged in to the jack and set real high, the headphones are blasting and the quality of the audio is degraded.

    if you have the levels adjusted correctly and it still sounds bad:
    1) check to make sure the plug is firmly inserted into the Mac.
    2) try a different cable. the 1/8" mini to RCA cables tend to short over time, so you may have better luck with a new one.
    3) not all cables are made equal. if sound quality is important, don't go cheap. yeah, anything will work, but over time, cheaper cables will go bad much sooner with constant use.

    as for the digital output. the jack DOES DO double duty. in addition to a 1/8" stereo analog output it has an 1/8" mini Toslink (optical) output. there are cables available that will connect this jack on the Mac with an Optical input on a Digital receiver. if you do not have an Optical input but only Coaxial Digital inputs, there are convertors, although expensive, that you can use. unless you plan to really use the surround sound from DVDs, it's not worth paying for this particular setup.

    hope this helps.
  3. shadowband macrumors member

    Jan 10, 2004
    This is what you want (provided that your stereo has digital optical input), although this particular product has been discontinued:

    Similar products are likely to be available from other vendors.
  4. strider42 thread starter macrumors 65816


    Feb 1, 2002
    Thanks to both of you. I've got a better idea of what I want if I decide to go digital.

    I was trying the 1/8" to rca cable again. This is a brand new set of cables I bought today. I tried it hooking it up to a portable radio's headphone jack and it worked great: no buzz, loud enough. But the moment I try plugging it into the iMac, the humming comes back. The same thing used to happen when I tried the same setup on my old G3 iMac, but I thought that was just the older cables I was using or something with that machine. I feel like I must be missing something obvious to get this to work without the hum. Thanks.
  5. nkawtg72 macrumors 6502

    Aug 16, 2007
    a hum is indicative of another issue. what power source do you have your mac and your stereo plugged in to?

    depending on your power source, you may find that you need to isolate the two from each other or use a power conditioner to get rid of the hum.

    i've been able to isolate and extinguish a hum with the use of a quality backup battery. i recommend APC brand. a VA350 or VA550 (i believe those are the current model #s) will work just fine. they will improve the quality (condition) of the power entering your Mac and Stereo and will help stop the hum.

    a hum sometimes is caused by poor grounding. make sure your outlet is wired properly. if it's an old house you may need to consider running a new power drop to ensure proper grounding.

    hope this helps
  6. nkawtg72 macrumors 6502

    Aug 16, 2007
    another thing to look for.

    table lights, work lights, can cause line noise that result in a hum. make sure if you have a work light plugged in that it's not using the same outlet or powerstrip as your Audio/Video equipment. different types of lights will interfere differently or not at all.

    unplug everything but the mac and stereo and see if it goes away. if it does, you'll know where your problem is.

    if it still hums then you know it could be a power issue as described above.
  7. strider42 thread starter macrumors 65816


    Feb 1, 2002
    Thanks again everyone. Wiring is a definite possibility, I don't have a lot of faith in the wiring in this house. Well, I might just put aside this idea for right now. Thanks.
  8. strider42 thread starter macrumors 65816


    Feb 1, 2002
    One last question on this. Would using a USB device to output the sound, maybe like the griffin iMic, eliminate the problem at all? Thanks.
  9. nkawtg72 macrumors 6502

    Aug 16, 2007
    it's possible but no guarantee. line noise from interference has a way of "oozing" through all the circuits of a device. but again, it could help. the powered USB bus the iMic is connected to could "condition" the signal and get rid of the hum. i've not tried that trick before.

    good luck
  10. johnmcboston macrumors 6502


    Sep 16, 2005
    The problem is something called a "ground loop". Basically you're connecting two different components form two different electrical lines, and they're connecting. Go a google search on Ground Loop for a much better explanation. :)

    I had this big time with my old imac, and to some extend with the new ones. Radio Shack has a Ground Loop Isolator for $17 that gets rid of this problem.
  11. pilotkato macrumors newbie

    Aug 20, 2009
    thanks. followed your guys advice. eliminated noise from my connection by unplugging printer which was plugged into same power strip as imac.

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