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Ground loop problems - pulling hair out and need help!!
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 3:22 am    Post subject: Ground loop problems - pulling hair out and need help!! Reply with quote


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Hello all,

I've read through so many different posts about ground loops that I feel like my head is spinning. First of all, let me say that I am not an expert electrician, so please try to keep suggestions / solutions as simple as possible. Let me explain my issue and hopefully someone can suggest a fix for me.

Here are the symptoms and the attempted fixes. First, some preamble… I have unplugged everything from my system so that the only things plugged in are the amp (Rotel RMB-1095) and the reciever (Integra 50.4), which are connect via Audioquest Sidewinder interconnects. I've disconnected everything else (Blu-Ray, Roku, DVR, etc...). No other a/v connections exist. I have also only connected 1 interconnect going from my amp to reciever to only run 1 speaker - my center channel. I have also unplugged the cable signal from the outside of my house, which should mean it cannot be the cable tv causing issues. Quick note - I don't have cable TV, only antenna - but I still do use Comcast as my internet provider.

When I plug in everything I mentioned above (all in the same outlet, btw), I get a deafening buzz from the center channel that is not affected by the volume knob - meaning I can turn the volume up or down and the same level of buzz exists. I know this isn't recommended, but I also tried putting a 3 prong to 2 prong reducer on the amp to see if that would solve the issue, and it did not. In addition, I tried running a 12 gauge wire from the chassis of the amp to a ground terminal on the back of the reciever. While this reduced the level of buzz, it did not eliminate it completely - it was still a very noticeable noise. If I just plug the speaker cables into the amplifier with out connecting the pre-amp with the audioquest cable, there is no buzz. I just purchased the Integra reciever, but I know that is not the source of the issue as I had the hum (although not quite as audible) before with my Rotel RSP-976 pre-amp. Quick note, I took the Rotel amp out of the equation and connected the center channel directly to the Integra (since it has an integrated amp), and there was no noise through the speakers.

Here is another scenario… when I plug my powered subwoofer (Velodyne HGS-12) in and connect it via audio connection to the pre-amp, I also get a buzz. However, this buzz is affected by the level of volume - turning the volume up on the back of the subwoofer caused the level of buzz to go up and down.

One other piece of information. I have run a dedicated circuit for just my a/v equipment, meaning no other lights, appliances, etc… are plugged in to the circuit. In addition, I own a monster power line conditioner - I have tried plugging all the equipment in to that as well as eliminating that from the set up and plugging the reciever and the amp directly into the wall. Finally, I just got all of my equipment (reciever, amp, subwoofer and line conditioner) back from my hi-fi dealer where they ran a bunch of tests to try to duplicate the issue, and were unsuccessful - meaning that the issue is defintely in my house and not with a piece of my equipment.

Ok, I think that might be the extent of everything I tried. Please help… I have tried everything I can think of and cannot solve the issue.
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Nashou66




Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY


PostLink    Posted: Tue Jun 11, 2013 3:29 am    Post subject: Reply with quote

Do you have another receiver to test? I have a feeling it is a faulty receiver. A normal Ground loop buzz is usually not defining, but a digital buzz will be, that is when the digital info gets all messed up and creates a loud buzz in a high pitch sound. Ground loop buzzes are at 60hz usually, a low hum/buzz.

Is there a way to do a factory reset on the integra?

Athanasios

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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 3:41 am    Post subject: Ground loop issues Reply with quote

I literally just purchased the integra, so factory setting are still enabled. In addition, the hi-fi dealer took all of my components and tried to replicate the issue in their shop, but got no buzz - meaning the issue has to do with my house.
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Tom.W




Joined: 09 Mar 2006
Posts: 6637



PostLink    Posted: Tue Jun 11, 2013 3:43 am    Post subject: Reply with quote

A good read on ground loops...

http://www.epanorama.net/documents/groundloop/index.html
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 3:44 am    Post subject: Reply with quote

Also, the sound is not high pitched, it is a deeper sound -- but was very loud without the 12 gauge wire going from the amp to the receiver ground terminal.
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 3:48 am    Post subject: Reply with quote

Thanks Tom - but I have read so many different posts on this -- I just don't understand them. The majority of time it seems like the noise is attributed to the cable coaxial line, but that is not the case with my set up, as I unscrewed it from outside my house. It seems like people talk about an isolation filter, but I don't know if it should be inserted into the interconnects cords or the power cord. Nor do I have any idea which one i should purchase.
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 3:51 am    Post subject: Reply with quote

Funny you should send that article though. I read it and actually emailed Tomi directly, but have not gotten a response. I thought he/she did the best job of explaining, but still didn't understand what I should do about it.
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AnalogRocks
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Location: Toronto, Ontario, Canada

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PostLink    Posted: Tue Jun 11, 2013 4:22 am    Post subject: Reply with quote

This dedicated circuit you ran; how many outlets are on it?
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 10:39 am    Post subject: Reply with quote

I believe there is only 1 outlet, possibly 2. When my house was being built, I got in after the electricians were done and ended the tun of one circuit early and ran another 2 wires (red and white) through the same conduit pipe into a dedicated 20 amp circuit. I didn't even consider that before. Could that be my problem?? The fact that the wires are in the same pipe or the fact that I only ran a red and white... no green??
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 10:43 am    Post subject: Reply with quote

Sorry - meant I ended the run of one circuit early, not the tun of one circuit early. What I mean is that I cut the wire at one outlet, preventing it from going to the next outlet. I then ran some additional wire just for that one outlet. There might be one more outlet daisy-chained to my dedicated outlet, but if there is there is nothing plugged in there.
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Curt Palme
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Joined: 08 Mar 2006
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Location: Langley, BC

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PostLink    Posted: Tue Jun 11, 2013 1:09 pm    Post subject: Reply with quote

By definition, this isn't a ground loop. A ground loop only exists when there is a fair distance (usually > 10 feet) between two ground points , and the tiny bit of voltage built up between the two points causes the hum.

Try a few things:

Move the amp and receiver to another room in the house with a speaker, any speaker. Connect the amp to the receiver, have both plugged into the same outlet, wire the two together and to the speaker, and see if you have the hum. Swap out your high falutin' interconnect with a generic RCA cable.

If the hum is still there, then something isn't playing nice between the receiver and the amp. You may need a different receiver or amp.
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sgroenendal




Joined: 06 Jun 2013
Posts: 11



PostLink    Posted: Tue Jun 11, 2013 1:41 pm    Post subject: ground fault Reply with quote

Ok Kurt,

I'll give that a try. Just a quick question though... when you say the definition is that there needs to be >10 feet distance between 2 points. What 2 points are you referring to? The amp and the receiver, the outlet and the amp, the outlet and the electric panel in the basement, etc...
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AnalogRocks
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Joined: 08 Mar 2006
Posts: 26690
Location: Toronto, Ontario, Canada

TV/Projector: Sony 1252Q, AMPRO 4000G


PostLink    Posted: Tue Jun 11, 2013 1:47 pm    Post subject: Reply with quote

sgroenendal wrote:
I believe there is only 1 outlet, possibly 2. When my house was being built, I got in after the electricians were done and ended the tun of one circuit early and ran another 2 wires (red and white) through the same conduit pipe into a dedicated 20 amp circuit. I didn't even consider that before. Could that be my problem?? The fact that the wires are in the same pipe or the fact that I only ran a red and white... no green??


This is my thinking.

You need all three wires, usually White ( neutral ) Black ( live ) and green ( ground ).

Sounds like you have the outlets wired wrong. For the two 15 amp outlets. are they wired alike? That is all three wires going to the same terminals the same way on the back of both outlets? ( See picture below for example )

On the 20 amp circuit with only two wires you are running without a ground. What side of the electrical box are your 15amp and 20 amp circuits coming off? If one is on the other leg of the 220volt line coming into your box it can cause a ground loop.

I think you should get an electrician in there to straiten this out.

Also do what curt suggested. Different room, set it up and try it out. All on the same outlet. See if your problem goes away.

Disclaimer:
I'm not an expert so you should consult an electrician and your local building codes.
Also as you say you aren't an expert either. Don't play with the wiring you can be injured or killed or with bad wiring, start a fire.



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sgroenendal




Joined: 06 Jun 2013
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PostLink    Posted: Tue Jun 11, 2013 2:35 pm    Post subject: Reply with quote

none of the outlets in my house use 3 wires - it is all red (hot) and white (neutral). All the whites come back to the ground bar in the electric panel. I guess I thought that I shouldn't have to run a dedicated ground since it is all running through metal conduit, where the outlet itself is screwed to the metal gang box, which is connected to the metal conduit, which is connected to the electric panel. As far as the 20 amp dedicated circuit, it is on the same side as the 15 amp circuit where all the wires are running through the same conduit.

Going to lug all my equipment down to the basement now to give it a try.
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AnalogRocks
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PostLink    Posted: Tue Jun 11, 2013 2:59 pm    Post subject: Reply with quote

Sounds like you need some proper wiring. Did the store who tested this have three prong outlets?
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sgroenendal




Joined: 06 Jun 2013
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PostLink    Posted: Tue Jun 11, 2013 3:42 pm    Post subject: Reply with quote

Yes, they did have 3 prong outlets.
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ecrabb
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PostLink    Posted: Tue Jun 11, 2013 4:23 pm    Post subject: Reply with quote

It was bugging me, so I had to fix it. Here's the above illustration with the outlet NOT shown upside-down. Wink

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AnalogRocks
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Location: Toronto, Ontario, Canada

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PostLink    Posted: Wed Jun 12, 2013 2:17 pm    Post subject: Reply with quote

sgroenendal wrote:
none of the outlets in my house use 3 wires - it is all red (hot) and white (neutral). All the whites come back to the ground bar in the electric panel.** I guess I thought that I shouldn't have to run a dedicated ground since it is all running through metal conduit, where the outlet itself is screwed to the metal gang box, which is connected to the metal conduit, which is connected to the electric panel. As far as the 20 amp dedicated circuit, it is on the same side as the 15 amp circuit where all the wires are running through the same conduit.

Going to lug all my equipment down to the basement now to give it a try.


Did you test it? How did it work?

**Having the neutral grounded at the electrical box is an old school way of doing things.

EDIT: up here in Toronto I have heard, from an electrician that they stopped grounding the neutral. Hence my saying it's the old way of doing things. They may still do that where you're from.

Keep in mind, I'm not an electrician nor an electrical contractor. Though, given enough money I would play one on TV Laughing



Have you thought about having your power service upgraded to 3 prong with a proper ground?

EDIT2: Not meaning necessary to up the amperage from what you have now to the max, just getting the HT wiring setup on 3 wire grounded outlets.

Better Mac? Very Happy

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Last edited by AnalogRocks on Wed Jun 12, 2013 9:15 pm; edited 1 time in total
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macgyver655




Joined: 22 Aug 2007
Posts: 8508



PostLink    Posted: Wed Jun 12, 2013 4:47 pm    Post subject: Reply with quote

AnalogRocks wrote:


Better Mac?



yep. Laughing


Last edited by macgyver655 on Wed Jun 12, 2013 9:26 pm; edited 1 time in total
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AnalogRocks
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Joined: 08 Mar 2006
Posts: 26690
Location: Toronto, Ontario, Canada

TV/Projector: Sony 1252Q, AMPRO 4000G


PostLink    Posted: Wed Jun 12, 2013 9:16 pm    Post subject: Reply with quote

macgyver655 wrote:
AnalogRocks wrote:
sgroenendal wrote:
none of the outlets in my house use 3 wires - it is all red (hot) and white (neutral). All the whites come back to the ground bar in the electric panel.** I guess I thought that I shouldn't have to run a dedicated ground since it is all running through metal conduit, where the outlet itself is screwed to the metal gang box, which is connected to the metal conduit, which is connected to the electric panel. As far as the 20 amp dedicated circuit, it is on the same side as the 15 amp circuit where all the wires are running through the same conduit.

Going to lug all my equipment down to the basement now to give it a try.


Did you test it? How did it work?


**Having the neutral grounded at the electrical box is an old school way of doing things.

EDIT: up here in Toronto I have heard, from an electrician that they stopped grounding the neutral. Hence my saying it's the old way of doing things. They may still do that where you're from.

Keep in mind, I'm not an electrician nor an electrical contractor. Though, given enough money I would play one on TV Laughing



Have you thought about having your power service upgraded to 3 prong with a proper ground?

EDIT2: Not meaning necessary to up the amperage from what you have now to the max, just getting the HT wiring setup on 3 wire grounded outlets.

Better Mac?



Read your PM. Very Happy


Read it ohh wise guru Laughing

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