Amplifier hum-please help

Discussion in 'Archived Threads 2001-2004' started by Matthew Anderson, Nov 20, 2001.

  1. Matthew Anderson

    Matthew Anderson Second Unit

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    I just got a 2 channel amp and I have everything hooked up correctly but I am getting a constant hum coming from the speakers that it just too loud for me. I really don't know where to begin. My banana connections are not as secure as they should but I don't know if that is the problem. Any help would be greatly appreciated.
     
  2. John Morris

    John Morris Guest

    Matthew: Three things to try: if any equipment is connected to your TV cable, use a cable ground loop isolator; next, make sure that ALL your RCA connections are in tight; finally, if your amp uses a three prong plug, try using a cheater plug. If the cheater plug stops the hum, you may want to plug your amp into a seperate electrical circuit, other than the one being used for your source components.
     
  3. Matthew Anderson

    Matthew Anderson Second Unit

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    John,

    Thanks for the suggestions on the amp hum. I do have a 3 prong connector for the amp but I don't know what a cheater plug is or where to get one. I tried the amp in another outlet but it did not help. Thanks again.
     
  4. John Morris

    John Morris Guest

    Matthew: Look here: [​IMG]
     
  5. Matthew Anderson

    Matthew Anderson Second Unit

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    Thank you John. You gave me just what I needed. I will check with Radio Shack for these items. I appreciate it.
     
  6. John Morris

    John Morris Guest

    Matthew: The FM trap will not do anything for your hum. The cheater plug may, and should cost about 60 cents available at Home Depot. Finally, the Ground Loop Isolator shown is the Holland CCl-1 and cost about $7, but may be hard to find locally. I got mine at a local store called Electrotex.
     
  7. Matthew Anderson

    Matthew Anderson Second Unit

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    John,

    You are the man! I can't believe the cheater plug worked. I bought one on the way home and tried it and I no longer hear the hum-amazing. Now all I need to do is find out how I can keep my banana plugs from coming out of the binding posts on the amp. I may have to cut them off and use bare wire or put some other kind of thicker banana on there if one exists. Thanks again for all your help.
     
  8. Wayne A. Pflughaupt

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    Matthew,

    While using a cheater plug is a quick fix, you really should try to find the source of the problem, which is, you have a ground loop. The ground connection is there for safety. If something goes wrong in the amp, the circuit breaker will trip. With no ground in place, if something goes wrong, you become the ground path when you touch it.

    There are a few places you can look for a ground loop.

    First, do you have a remotely-located powered sub (that is, away from the other equipment)? If so, there is a good chance that it is on a different circuit from the rest of the gear. For a test, try running an extension cord and plugging it into the same outlet as the rest of the equipment. If that stops the hum, you need to consider having dedicated service run for your system, or at the very least have an electrician move that circuit to the same phase or service leg as the HT system.

    The next likely culprit for a ground loop is a CATV service feed. Disconnect it from the system. If that makes the hum go away, get back to us. There are a few things you can do to eliminate it.

    Also, if you have a satellite system, the installer might have “cheated” on the ground. The ground for the dish should be connected to the house electrical ground.

    Regarding the banana plugs, try changing them. Perhaps your old amp or receiver had undersized holes n the binding posts, and over time the bananas were “squeezed down,” making them a loose fit in your present amp.

    Regards,

    Wayne A. Pflughaupt
     
  9. Matthew Anderson

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    Thanks Wayne for all the useful information. I never thought about the safety issue with the ground thing but that is something I will look into. I don't want to take any unecessary chances. I will let you know if it turns out to be the TV connection. I don't have cable tv but I do have a coax feed coming from the master antenna in the attic. The satellite is also coming from this feed. I will try some different banana plugs to see if that will hold. Thanks again.
     

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