Speaker buzz when MBP is connected to receiver

Discussion in 'MacBook Pro' started by jeremy.king, Nov 15, 2006.

  1. jeremy.king macrumors 603

    jeremy.king

    Joined:
    Jul 23, 2002
    Location:
    Fuquay Varina, NC
    #1
    I don't know a whole lot when it comes to sound, so I appeal to you for advice.

    I connected my MBP to my stereo receiver using a mini stereo to RCA cable (from Monster), and I have two issues.

    First a really annoying buzzing sound can be heard through the receiver speakers only when I connect my MBP. The wifes MB and my iPod do not produce any buzz when using the same cable connection. Edit: Also worth mentioning, no buzz can be heard if I connect headphones, its only this AV receiver connection. Any thoughts?

    Second, the levels are really weak with ALL of my devices such that I really have to jack the volume on my receiver just to hear anything. For example, when I watch a DVD or Cable TV (both digitally connected) I usually set the volume level to around 13 on my receiver, with my laptops/iPods I have to set the volume to around 35. Do I really need to preamp the signal with some device or is there a preference/application that will do this from the MBP? I have not tried another cable and don't have an available optical connection to use digital.

    Thanks in advance.
     
  2. drewwerd macrumors newbie

    Joined:
    Nov 12, 2006
    Location:
    Cleveland, Ohio
    #2
    wow i am such a n00b, i accidently poasted 2 times so this is my lame ass attempt at removing one of them. Blast away i deserve it :(
     
  3. drewwerd macrumors newbie

    Joined:
    Nov 12, 2006
    Location:
    Cleveland, Ohio
    #3
    Bzzzzz....

    Sounds like you either have a common ground loop, or perhaps if the cabe running between your mini 2 rca, is long enough it is just acting like an aentenna for unwanted rf energy. ground lops are often caused because of an unbalanced connection (like rca) or a lacking of a common ground between the 2 pieces of equipmen. in a way they are kind of linked; any way i suggets first try using a really short patch cable less than say 2 m, and moving both the amp and the computer far far away from any other running electronics, including but not limited to tv's flourescent lighting ( a big one, so just turn the light off) and also try plugging both pieces of equimpent into the same power strip. other than that there are several commercially available buzz boxes. you can find them looking in a broadcast supply compant like markertek.com, ( i think i spelled that link correctly) RCA was never intended to be used over 2.5 m runs, though people routinely do so any way and can get away with it. xlr or similar 3 wired (per channel) are more popular for this reason. as for the signal level issue, i find on my iPod (30 gb video) that max volume is roughly line level power. so do not be afraid to crank the power on the computer's end, say max sys volume and max iTunes, but i would reccoment first starting out with iTuynes maxed out and slowly increase the sys vol.untill it matches say you dvd/cd player. Hope this book of worthless info helps :p
     
  4. Transeau macrumors 6502a

    Transeau

    Joined:
    Jan 18, 2005
    Location:
    Alta Loma, CA
    #4
    a few things...

    1) Are you on A/C or Battery?
    2) If on A/C, are you using the 2-Prong or 3-Prong power
    3) How long is the cable from the MBP to the Receiver?
    4) If it's longer than 3ft, is it shielded?
     
  5. jeremy.king thread starter macrumors 603

    jeremy.king

    Joined:
    Jul 23, 2002
    Location:
    Fuquay Varina, NC
    #5
    I realized that I never responded to this.

    I'm not buying the cable claims, since the MB and iPod are fine when using the same cable. It seems to be my MBP only.

    Also, this won't be an issue come Feb as I plan to invest in an Apple TV.
     
  6. trudd macrumors regular

    trudd

    Joined:
    May 27, 2004
    Location:
    Texas
    #6
    I have the same problem with my 1st gen MBP. I bought a ground loop isolator from Radio Shack. Ran about $18, but it solved my problem.

    I recall hearing that happened on a few old Powerbooks when the 3 prong adapter was used. The computer didn't seem to like being grounded...
     
  7. laidbackliam macrumors 6502

    Joined:
    Feb 1, 2006
    #7
    install the chud tools and turn one core off. sounds dumb, but it works.
     

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