Annoying Hum with new amp

Discussion in 'Archived Threads 2001-2004' started by Mike Nep, Apr 23, 2002.

  1. Mike Nep

    Mike Nep Stunt Coordinator

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    I just hooked up my new odyssey amp and now I have an annoying hum. I did the usual trouble shooting (pulling out connects) and found that when I disconnected my S video cable the hum completely disappearred. Problem is it's hard to watch movies without the S Video plugged in. Has anyone had this problem and what did you do to remedy the problem? Please help and thank you.
     
  2. Arthur S

    Arthur S Cinematographer

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    Mike

    First thing I would try is a cheater plug for the amp. This would be just a workaround (if it works) till you can do something about your apparent ground loop.

    PS noise from a separate amp has got to be one of the most frustrating experiences for us. Adding separates amps to receivers is one of the most frequently discussed topics in this forum. All too many find that they have a noise problem on one kind or another when they first hook up the amp. Usually, things work so you can enjoy the amp. In my experience, receivers are far less prone to these kinds of noise problems. At least you seem to know the culprit. More substantial recommendations should be forthcoming from the electrically more astute.
     
  3. Ron Reda

    Ron Reda Cinematographer

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    Mike,

    First off, congrats on your purchase...that amp will provide you with much enjoyment! I'm sure you waited a while, but it will be well worth it.

    I had the same problem with my Stratos when I first got it. I narrowed it down to my TV. When the TVs on, I get a slight hum from the speakers that are connected to the amp. When the TVs off (while listening to CDs), there's no hum. I too tried a cheater plug and, while it worked for about 30 minutes, the problem soon returned. I also called Klaus for some recommendations, so I suggest you do the same.

    As far as remedying the problem, I never did. I just wanted to make sure that there were no issues with the amp and once that was determined, I ceased caring and started listening! Anyway, usually the sound from the speakers masks the hum, so I really only hear it during the absolute quietest protions of a movie.
     
  4. Mike Nep

    Mike Nep Stunt Coordinator

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    Thanks for sharing your experiences/ideas. I'll try the cheater plug idea but what potential risks am I taking by using one of these little guys, ie: frying amp, burning down house? Also, I know for a fact that it has something to do with my s video connect running from the dvd player to the TV. It is a better cables silver serpent s video. Anyone come up with fixes for these same problems with S video.
     
  5. chung

    chung Stunt Coordinator

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    Mike:

    It's most likely due to your cable TV connection from the outside having a different ground than your amplifier. Remove the cable TV type F connector from your TV and find out if the hum goes away. You should make sure that the cable box, which may be mounted on an outside wall of your house, is well grounded to the electrical panel of your house. You can also isolate the cable connector by using a 75 ohm to 300 ohm transfomer, followed by a 300 ohm to 75 ohm transformer. Those transformers are available at Radio Shack.
     
  6. Mike Veroukis

    Mike Veroukis Second Unit

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    Hi Mike!
    Chung is most likely correct here. I had the same problem but with a full blown receiver. When I set the input to my CD player there was no hum. When I set the input to my VCR or computer there was hum. Why computer? I use a cable modem at home. I noticed that when I disconnect the cable leading into the house the hum disappears completely from all inputs. Of course the video and Internet signals are also lost. [​IMG] The way I fixed this was by buying a cable grounding loop from Radio shack. Now I have it set up so that the cable that leads into the house goes through this little grounding loop which grounds the incoming cable to the ground that my amp is using. I'm sure Chung could go into a lot more detail as to what's really going on. There's lots on this topic if you do a search for grounding loop blocks.
    Oh yeah, you may want to experiment with a cheater plug, but I've heard it's not good to use one as a permanent solution. I'm sure Chung could elaborate here as well.
    Good luck!
    - Mike
     
  7. rodneyH

    rodneyH Supporting Actor

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    check out my responce to "Rotel owners please read" thread, it may help.
     
  8. Mike Nep

    Mike Nep Stunt Coordinator

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    Thanks for all the info you guys. Fortunately, I got my new Homegrown Silver Lace interconnects in and replaced the old ones I was using today. NO MORE HUM![​IMG] Those old interconnects must've not liked my amp or vice versa because it just started with the addition of the amp. Can't say I like the sound too much of the Homegrowns but it's only day one. Please get better. Once again, thanks for the help.
     
  9. RonaldW

    RonaldW Auditioning

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    I had a ground loop hum problem from my cable connection when I plugged in my Outlaw 770. I called the TV cable company and they doubled checked their grounding (steel rod extending into the earth)and gave me an isolated feed to screen out any problems from any other subscribers on my block.

    No luck. I used the back to back 75-300 Ohm matched transformer solution that someone else suggested but it noticeably degraded my analog cable signal. I asked the cable line tech for a recommendation and he told me that for problem cases they purchase something called a "hum bucket" from a local high fi shop. It turns out to be a $8 ground loop isolator with surge protection from China. Anyway, it took care of the hum with no noticeable picture degradation.
     

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