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Dish receiver causes speaker hum with three prong plug?

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Posted on March 28, 2021 at 09:43:26
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
My Parasound a23 2 channel stereo power amp comes with a three prong plug. when using that type plug, I get speaker hum with Dish receiver hooked up feeding audio to the P5 preamp but not when it's not hooked up it, also has a three prong plug. I've been using two prong with power amp to defeat the speaker hum. I don't like using the two prong and loosing the grounding prong. I've been told on another forum that it was a common problem with Dish receiver use through stereo. Also, they mentioned the use of a ground loop isolator would solve the hum problem so I could use the factory 3 pronged plug that came with the power amp. Anyone familiar with the ground loop isolator they speak of? Through unhooking things, I for sure isolated the problem to be because of the Dish receiver which, was stated to be a common problem. I'd sure appreciate all input and, maybe some links to the type ground loop isolator others were referring to. Thank You!

 

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RE: Dish receiver causes speaker hum with three prong plug? , posted on March 28, 2021 at 18:50:50
Duster
Manufacturer

Posts: 16991
Location: Pacific Northwest
Joined: August 25, 2002



A ground loop isolator is very effective and will easily solve the problem, alley -kat.

This model from a reputable manufacturer also features surge protection.

See link:

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 11:37:26
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
Thanks very much!

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 19:54:56
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
I was told on DIY Audio I couldn't use the one you linked me to and that I need one of these? I'm confused https://www.amazon.com/s?k=RCA+ground+loop+isolator

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 20:57:46
6bq5
Audiophile

Posts: 3532
Location: SF Bay
Joined: August 16, 2001
I would go back to grounding your amp-
Use the isolator that Duster Recommended, and float the ground of the dish unit-
Happy Listening

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 21:13:41
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
In other words, I just need to install the isolator and that's all?

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 21:16:46
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
don't quite understand what float the ground means?

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 21:28:27
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
I've ordered isolator hope it works I want to thank you, and Duster!

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 29, 2021 at 21:41:45
6bq5
Audiophile

Posts: 3532
Location: SF Bay
Joined: August 16, 2001
When you use a 2 pronged plug on your amp (that would otherwise use a three pronged plug) you are floating the ground-

I have a very similar problem when I use a computer to feed the HiFi w/ music - if the Computer is grounded - or the monitor - I get a Hum-
If I float the ground for the computer/monitor- no Hum!
Happy Listening

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 30, 2021 at 06:13:02
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
I think I've got it now, I should use the factory 3 prong cable on power amp and use 2 prong on the Dish receiver correct? I'll also, install the isolator Duster linked me to when it gets here Friday. Thanks again!

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 30, 2021 at 10:04:16
Duster
Manufacturer

Posts: 16991
Location: Pacific Northwest
Joined: August 25, 2002
To eliminate ground loop hum caused by a Dish receiver, you need to isolate the ground of the coaxial cable.

It's a common problem, solved by a rather common coaxial cable ground loop isolator.

If the device does not work (it will work), you can simply send it back to Amazon for a refund.

Read the end user reports posted on the Amazon page I provided for you, alley -kat.

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 30, 2021 at 11:19:18
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
Yeah, I read the reviews on Amazon and it sounds like it should work much appreciated Thanks!

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on March 31, 2021 at 14:29:50
Duster
Manufacturer

Posts: 16991
Location: Pacific Northwest
Joined: August 25, 2002
All you need is the ground loop isolator and a coaxial cable to place between the ground loop isolator output and the Dish receiver input.

You won't need to float the AC ground prong of the amplifier nor the Dish receiver to solve the hum issue, alley -kat.

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on April 2, 2021 at 06:16:37
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
Still waiting for isolator to arrive it ordered early Monday, was suppose to be here today but, they just shipped it at almost midnight last night now they are saying arriving tomorrow. I'm beginning to wonder about Amazon anymore. Also, I've been hearing rumors lately about about them allowing Politics to influence their agendas more than anything.

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on April 2, 2021 at 11:06:48
Davey
Audiophile

Posts: 2186
Joined: September 26, 2013
That gadget Duster recommended won't work anyway.

Among other things, that's a DC-blocker and your sat dish needs the DC excitation voltage for the head-amp. When you install it your hum problem might be alleviated, but you won't have any TV. :)

Dave.

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on April 2, 2021 at 19:13:36
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
I guess I'll find out tomorrow when it arrives according to reviews, it has worked for some people.

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on April 3, 2021 at 08:38:26
alley -kat
Audiophile

Posts: 268
Location: southeast missouri
Joined: August 7, 2003
Well, I received ground loop isolator installed it and it works great TV still works and zero hum, with three prong factory power cable attached to my Parasound a23 power amp as it should be Thanks Duster!

 

RE: Dish receiver causes speaker hum with three prong plug? , posted on April 8, 2021 at 09:01:11
floydandrews
Audiophile

Posts: 280
Location: Port Townsend, WA
Joined: December 29, 2003
I am glad that your problem is solved. Another way to do it would be to use an RCA cable that includes an isolation transformer between your preamp and TV source. I use a Radio Shack ground loop isolator (catalog #270-054) between my Roku streaming device and my preamp. I do it this way because I use a powered booster between my antenna and TV/streamer and need a DC connection. The isolation transformer does not seem to negatively affect the sound quality of music that is part of movies and TV shows. Just another way to accomplish the same result.

 

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