ground loop?

Discussion in 'General Audio Discussion' started by VQLT, Jul 30, 2003.

  1. tater415

    tater415 New Member

    Messages:
    28
    Location:
    alta loma ca
    I just got my 2 Altec 9440 amps back from being rebuilt and they have hum. I checked to make sure they had Good Grounds, everything checks out fine, I disconnected all the inputs and just left the speakers hooked up and they still have hum, looks like they're going to have to go back to the shop is there anything else that I can check that I may have missed?
     
  2. EJC1

    EJC1 Member

    Messages:
    95
    Does it have a 3 prong plug? might be worth trying a 3 to 2 adapter but do not connect the ground wire to the outlet
    Does the Amp have a 2 prong plug? try flipping over.
    Is the outlet wired properly?
    How are the other pieces of hardware connected? are they all grounded to the same point? or are plugged into different outlets.
     
  3. tater415

    tater415 New Member

    Messages:
    28
    Location:
    alta loma ca
    Thanks for responding with suggestions ejc1, I did try it with no ground connected and I still had the same results. the amps originally came with a grounded power cord, I checked the receptacle in the wall, it is wired correctly and it has a ground. the only thing I didn't do as you suggested was to flip the power cord. I took both amps and put them back in the shop I'm still waiting for them to be reworked, one thing I did do was I put them up against a crown ce2000 amp, the Altec 9440 amp blew Crown amp away, the Altec makes more Bass and just sounds so much better. The crown amp is rated 1320 amps and the Altec is rated at 800 amps bridged, so when I turn the volume up and got the meters on the Altec showing 50%the Crown amp clipping light comes on, I love these old altec amps,they were made to perform
     
  4. edwyun

    edwyun Super Member

    Messages:
    1,028
    Location:
    NY/NJ, USA
    Last edited: Mar 24, 2017
    EJC1 likes this.
  5. I LIKE MUSIC

    I LIKE MUSIC Well-Known Member

    Messages:
    987
    Location:
    You can't get there from here!
    So that would include things like a microwave, dishwasher, refrigerator, washing machine and so on.

    If so that is not necessarily the best idea in terms of safety. It will also defeat the intended purpose of any ground fault interrupter outlets/breakers that may be in use.
     
  6. ARIZONA RAT

    ARIZONA RAT New Member

    Messages:
    19
    Location:
    apache juction,AZ
    ive been doing it for 10 yrs no prob.... and yes all have to be gone in the house, only one will cause the ground loop... I was so happy to get rid of that noise ;))
     
  7. aje123

    aje123 Member

    Messages:
    66
    Hi all, I have another issue which i think is a ground loop problem.I hooked up tuner,preamp,amp and 2 speakers,got loud buzzing in speakers.I thought is was the cable i made(per other topic here PREAMP ISSUE) but that was not it. I unhooked all, just left amp and speakers connected to each.Amp only has 2 rca inputs and hi level speaker connections.Kenwood km-893 amp. With the amp on i have input cables plugged into amp going to nothing,when i touch the + of the rca input i get the loud buzzing,or if i hook it up to anythig even with another component unplugged and off same buzzing??? THANK YOU













    +
     
  8. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    22,299
    Location:
    uk.. the middle bit
    you have a big problem that is probably small .. get your house wiring checked right away and your appliances ..removing grounds from appliances is downright dangerous and should never be done under any circumstance . it is their for your safety .
    i do suspect the house ground is missing or a bad neutral connection
     
    Last edited: May 21, 2017
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  9. ARIZONA RAT

    ARIZONA RAT New Member

    Messages:
    19
    Location:
    apache juction,AZ
    get rid of all three prongs throughout the house........ cant leave even one......
     
  10. aje123

    aje123 Member

    Messages:
    66
    What about a dedicated outlet right from panel box??
     
  11. ARIZONA RAT

    ARIZONA RAT New Member

    Messages:
    19
    Location:
    apache juction,AZ
    prob not... this is a cheap fix, try it....
     
  12. aje123

    aje123 Member

    Messages:
    66
    What would be the cheap fix arizona??
     
  13. I LIKE MUSIC

    I LIKE MUSIC Well-Known Member

    Messages:
    987
    Location:
    You can't get there from here!
    Please, those reading this thread, do not remove all of the ground connections all over your house. Regardless of what one person may have done, it is not safe. It will defeat any ground fault interrupters and raise the risk of shock, period, one and done.

    There is a reason why those ground connections exist. There is a reason for GFCI outlets and breakers. It is called safety, one and done.
     
    gtv2000 and petehall347 like this.
  14. aje123

    aje123 Member

    Messages:
    66
    Im with you (ILM) on that. There has to be an easy fix?? thanks
     
  15. aje123

    aje123 Member

    Messages:
    66
    Hey all. i was just screwing around with this ground,loud hum issue.I ran a ground wire from tuner to preamp,then touched the other end to amp chassis and loud hum went away,just good clear loud music.I have a problem since i did this,my preamp volume will go up but not down.IT is lighted all the light stay on like the volume is all the way up.
    This problem only since i added the gound wire,so i disconnected the ground from the preamp.This did not help.The ground is just from tuner to amp chassis,not hooked to nothing else and hum buzz is gone. ??? THANK YOU
     
  16. ARIZONA RAT

    ARIZONA RAT New Member

    Messages:
    19
    Location:
    apache juction,AZ
    cheap fix is getting rid of all ur 3 prongs in the house.....
     
  17. I LIKE MUSIC

    I LIKE MUSIC Well-Known Member

    Messages:
    987
    Location:
    You can't get there from here!
    It is cheap way to raise one's risk of electrical shock. Just because one person has done it does not mean that it is right.

    This is just a straw man response.

    That is like a a person that has driven drunk for 10 years telling you that they have done it for 10 years so it is okay and safe.

    This is not rocket science. Ground connections and GFCI outlets (which the removal of the ground will defeat and cause not to work) have a specific function. That is to offer protection from electrical shock and possible death.

    To recommend this indicates a lack of understanding.


    No matter what a person says, this is not a good idea. End of story, period, one and done.

    Will doing this immediately result in a shock hazard, likely not, but it removes a very important layer of protection.

    I understand that I am being repetitive, but this after all a sticky. Those that might just be starting out in this hobby and even others with out experience with electricity will read these posts and might follow this dangerous information.
     
    gtv2000 likes this.
  18. Harryconover

    Harryconover Active Member

    Messages:
    222
    Ac wiring of the outlet needs to be checked first a small plug in wiring checker (only a few dollers at homedepo) ,alwise check the ac first . Ground loops by defanistion is more than one path to ground . For safetys sake you should never use a ground lift on the line cord ,so don't but you have him the sulution is simple but messy all of your cables need to have there shield connected at ONE end only letting the ground to be provided by the ac cord only . The end of the signal cable that grounded is connected
    To your preamp or recivor if a pice has a two pin ac cord run a single wire from its chassis to to your main un
     
  19. aje123

    aje123 Member

    Messages:
    66
    thanks all,i will play around with this on the weekend. Like i said its just the preamp working weird.This could just be a ground issue?? Its odd that i cured one problem but made another problem. THANK YOU
     
  20. Harryconover

    Harryconover Active Member

    Messages:
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