Hiss/Ground Loop..Need Some Help

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wingnut4772
wingnut4772 Posts: 7,519
edited October 2006 in Troubleshooting
Hi guys. I am still trying to iron out the last bit of noise from my system and the Earthquake Guys suggested trying a ground wire from my pre to the amp as I have pretty much narrowed it down to the pre. Mind you it's miniscule but I want perfect.:p

My question is : my pre has a ground chassis connection but the amp does not...so where do I attach the ground to the amp?
Sharp Elite 70
Anthem D2V 3D
Parasound 5250
Parasound HCA 1000 A
Parasound HCA 1000
Oppo BDP 95
Von Schweikert VR4 Jr R/L Fronts
Von Schweikert LCR 4 Center
Totem Mask Surrounds X4
Hsu ULS-15 Quad Drive Subwoofers
Sony PS3
Squeezebox Touch

Polk Atrium 7s on the patio just to keep my foot in the door.
Post edited by wingnut4772 on
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  • F1nut
    F1nut Posts: 49,856
    edited September 2006
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    First off, is it a hiss or a hum as it makes a difference as to a possible solution.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited September 2006
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    both. It is slight but it is magnified somewhat when the pre is turned on.
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
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  • F1nut
    F1nut Posts: 49,856
    edited September 2006
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    Hmmm....well a slight hiss from your tweeters can be normal, but a hum isn't. Try running a wire from the ground screw on the pre to a chassis screw on the amp. Make sure the wire contacts bare metal on the amp.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited September 2006
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    F1nut wrote:
    Hmmm....well a slight hiss from your tweeters can be normal, but a hum isn't. Try running a wire from the ground screw on the pre to a chassis screw on the amp. Make sure the wire contacts bare metal on the amp.

    Ok. Any screw on the amp chassis? It does not matter where?
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
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  • F1nut
    F1nut Posts: 49,856
    edited September 2006
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    Any screw on the back should ground to the chassis.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited September 2006
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    Ok. Further exploring is telling me it's the Satellite. Funny thing it is only going away when I remove the HDMI cable from the Sat box..not the actual cables coming in from the outside...?

    Even at full volume I have to have my ear right up against the speaker to hear it but still.. I 'd rather it go away. All the other inputs are fine.
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 49,856
    edited September 2006
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    Ground loop hum seems to be a fairly common problem with those satellite boxes. You'll need an isolation device for the box. Polk sells one, but I'm sure you could find one locally, maybe Rat Shack.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • BlueMDPicker
    BlueMDPicker Posts: 7,569
    edited September 2006
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    Did your satellite provider use a ground separate from your house electrical service ground? If so, that could cause the problem.
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  • adam2434
    adam2434 Posts: 995
    edited September 2006
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    Posted this a while back. This isolator did a nice job of eliminating the ground loop hum from my cable TV. Polk sells one for around $50. This one is only $12. I don't know what the differences are, but this $12 one did the trick for me.

    http://www.polkaudio.com/forums/showthread.php?t=43938&highlight=cisp
    5.1 and 2.0 ch Basement Media Room: Outlaw 975/Emotiva DC-1/Rotel RB-1582 MKII/Rotel RB-1552/Audiosource Amp 3/Polk LS90, CS400i, FX500i/Outlaw X-12, LFM-1/JVD DLA-HD250/Da-Lite 100" HCCV/Sony ES BDP/Sonos Connect. DC-1/RB-1582 MKII/Sonos Connect also feed Polk 7C in garage or Dayton IO655 on patio.
    2.1 ch Basement Gym: Denon AVR-2807/Klipsch Forte I or NHT SB2/JBL SUB 550P x 2/Chromecast Audio.
    2.0 ch Living Room: Rotel RX-1052/Emotiva DC-1/Klipsch RF-7 III/Sony ES BDP/LG 65" LED.
    2.0 ch Semi-portable: Klipsch Powergate/NHT SB3/Chromecast Audio.
    Kitchen: Sonos Play5.
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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited September 2006
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    Thanks. I read somewhere that that does not work on Sat...? I looked at the box on the side of the house where they seem to have all the Sat cables and the green wire is not connected to anything.
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
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  • gregvet
    gregvet Posts: 9
    edited September 2006
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    The green wire on my satellite cable is connected to a copper rod in the ground.
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  • polkatese
    polkatese Posts: 6,767
    edited September 2006
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    Darla, the green wire has to be connected to the common ground in the box (which usually there on newer houses). The guy who installed mine "preached" about this, noting that some sloppy installers (which DirecTV has known to sub these jobs out to) will skip this part.
    I am sorry, I have no opinion on the matter. I am sure you do. So, don't mind me, I just want to talk audio and pie.
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  • BlueMDPicker
    BlueMDPicker Posts: 7,569
    edited September 2006
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    wingnut4772 wrote:
    Thanks. I read somewhere that that does not work on Sat...? I looked at the box on the side of the house where they seem to have all the Sat cables and the green wire is not connected to anything.
    Many (probably more like most) installers drive a copper rod near the foundation and in close proximity to the coax entrance point. Yep, that's a ground--but, it's at a different potential to your electrical service ground. No big deal until you start grounding other components in the signal path. The two grounds, seeking to balance potential, set up a hum.

    If your sat block isn't grounded to anything, try finding an easy point inside the house, using a splitter with ground, to attach to the green ground in a duplex receptacle.
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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited September 2006
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    I attached the ground from the Sat.cable to the house ground and it made it slightly worse.
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
    · Share on FacebookShare on Twitter
  • BlueMDPicker
    BlueMDPicker Posts: 7,569
    edited September 2006
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    Now, use cheater adapters (three in, two out) to find the looping device. When you find it, get something like the PS Audio PCs with removable ground pin for a permanent fix.
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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited October 2006
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    Well FPL came out to the house and told me that I have the old water ground and not the 'two stake' kind. I have an electrician coming out to update my ground. Would this make a difference with that annoying little hiss and hum? Nothing else I do seems to eliminate it totally.
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
    · Share on FacebookShare on Twitter
  • BlueMDPicker
    BlueMDPicker Posts: 7,569
    edited October 2006
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    How many of your components are grounded (all three prongs intact)? Since you physically ground the components together via interconnects, it's really only necessary for one of the components to have a power plug ground--usually the amplifier/AVR is best IMO. Did you try cheaters on the components to see if that impacted the issue yet?
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  • wingnut4772
    wingnut4772 Posts: 7,519
    edited October 2006
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    Yes. I tried everything and it's still there. Its miniscule..but there.
    Sharp Elite 70
    Anthem D2V 3D
    Parasound 5250
    Parasound HCA 1000 A
    Parasound HCA 1000
    Oppo BDP 95
    Von Schweikert VR4 Jr R/L Fronts
    Von Schweikert LCR 4 Center
    Totem Mask Surrounds X4
    Hsu ULS-15 Quad Drive Subwoofers
    Sony PS3
    Squeezebox Touch

    Polk Atrium 7s on the patio just to keep my foot in the door.
    · Share on FacebookShare on Twitter