Ground Loop Problems - Solved

[Cut-Throat]

I fought ground loops on my System for years. When I got a Pair of Oris Horns that were 115db, the ground loop hum was too much to bear.
So, I concentrated on fixing the problem... All of the gadgets and Isolation stuff, just plain did not work. My system has SET Monoblocks that are located close to the speakers. The speakers are 20 feet apart. I have all the electrical stuff on 1 circuit. Plugging all of the components into 1 outlet helped, but did not eliminate the hum.

Solution: -- I put a GFCI on the circuit at the Electrical Panel, so the entire Stereo Gear Circuit was protected from ground faults (much safer than a 3 prong plug with a safety ground per the NEC) . Then I lifted the ground of ALL of the components with 'cheater plugs'. Dead Silent and Safer.

I spent years on this problem and hope this can help someone.

 

[kach22i]

So...................you are not standing in the dark yet?

Short run required?

Why not one, large GFCI?
https://www.bobvila.com/posts/76168-why-not-one-large-gfci

A GFCI breaker trips at about 5/1000 of an amp. Since there is no such thing as a perfect insulation, you will eventually have enough wire installed so that the normal leakage current exceeds the 5/1000 of an amp & you are standing in the dark.

Won't your stereo system be drawing so much power that it's going to set the panel GFCI off on Tchaikovsky's - 1812 Overture (Full with Cannons)?

Just asking, not saying.

I have to upgrade my panel and supply to house in the future, so I'm here to learn.

 

[Speedskater]

Solution: -- I put a GFCI on the circuit at the Electrical Panel, so the entire Stereo Gear Circuit was protected from ground faults (much safer than a 3 prong plug with a safety ground per the NEC) . Then I lifted the ground of ALL of the components with 'cheater plugs'. Dead Silent and Safer.

I would not post such a dangerous and against electrical code suggestion on any forum.

 

[Cut-Throat]

I would not post such a dangerous and against electrical code suggestion on any forum.

Not against Code in the least: - You don't know what you're talking about. And what I proposed is actually much safer than a circuit without GFCI Protection. So, if someone uses an old appliance with a 2 prong plug there is no Ground Fault protection at all, which you seem to be OK with. And which happens daily in thousands of homes in the U.S.

So, understand that circuit in my house STILL has 3 prong outlets, all I did was add GFCI protection, making it safer... That is what the Code is specifying. The Code DOES NOT say that you cannot use old 2 prong appliances anymore!! In fact lots of people with Old Fisher Tube Receivers have 2 Prong Plugs and are not protected by Ground Faults.

--- This is the actual NEC Code for your info:

Replacing Receptacles to Meet the NEC

The NEC requires receptacles installed on 15 and 20 ampere branch circuits to be of the grounding-type and it requires the grounding contacts of those receptacles to be effectively grounded to the branch circuit equipment grounding conductor [210-7]. However, the Code allows the installation of any of the following installations when replacing a 2-wire nongrounding-type receptacle where no ground exists in the outlet box [210-7(d)(3)], Figure 9/10:

(a) Replace the 2-wire receptacle with another 2-wire receptacle.

(b) Replace the 2-wire receptacle with a GFCI-type receptacle and marked the receptacle with the words “No Equipment Ground.”

(c) Replace the 2-wire receptacle with a grounding-type receptacle where protected by a GFCI protection device (circuit breaker or receptacle). Since the grounding terminals for the receptacles are not grounded, the receptacles must be marked with the words “GFCI Protected” and “No Equipment Ground.”

A grounding-type receptacle that is GFCI protected without an equipment grounding conductor is a safer installation than a grounding-type receptacle with an equipment grounding conductor (if GFCI protection is not provided). This is because the GFCI protection device will clear a ground-fault when the fault-current is 5 milliamperes (+ or – 1 milliampere), which is less than the current level necessary to cause serious electric shock or electrocution

 

[cjm2077]

Have you tried swapping out components to find which one causes the loop issue?

 

[Cut-Throat]

So...................you are not standing in the dark yet?

Short run required?

Why not one, large GFCI?
https://www.bobvila.com/posts/76168-why-not-one-large-gfci


Won't your stereo system be drawing so much power that it's going to set the panel GFCI off on Tchaikovsky's - 1812 Overture (Full with Cannons)?

Just asking, not saying.

I have to upgrade my panel and supply to house in the future, so I'm here to learn.

I did not put a GFCI on the Entire Panel, as the Question you linked to was inquiring about. I only put a GFCI on the ONE Dedicated Circuit in the panel where my Stereo Gear resides. I have never had a Ground Fault there in 2 years, except when I was testing the GFCI. I only have 5 outlets along one wall where my gear is plugged into.

 

[RayDunzl]

I run "balanced" power in the rack.

60VAC (differential) on both the hot and neutral leads, referenced to Earth, and Earth continuous back to the breaker panel.

The Equitech has GFCI outlets, all my gear comes off it, whether two or three pronged plugs.

Some gear that hums from a standard outlet - an old guitar amp, an old active crossover, as examples - go silent when powered through the Equitech.

 

[Speedskater]

Not against Code in the least: - You don't know what you're talking about.

Well I am a member of the NEC code forum.
The NEC does not permit wiring a current & GFCI breaker protected circuit without a Safety Ground (EGC) wire.
The only place a receptacle may be wired without a Safety Ground wire is in an ancient two wire circuit. In that case a 3 pin GFCI receptacle may replace the old 2 pin receptacle (there are restrictions involved).
a GFCI (without a Safety Ground) will not perform one of the primary tasks of a circuit breaker. That is to trip if there is a Hot to chassis short circuit. a GFCI does not check for this problem.

 

[Cut-Throat]

Well I am a member of the NEC code forum.
The NEC does not permit wiring a current & GFCI breaker protected circuit without a Safety Ground (EGC) wire.
The only place a receptacle may be wired without a Safety Ground wire is in an ancient two wire circuit. In that case a 3 pin GFCI receptacle may replace the old 2 pin receptacle (there are restrictions involved).
a GFCI (without a Safety Ground) will not perform one of the primary tasks of a circuit breaker. That is to trip if there is a Hot to chassis short circuit. a GFCI does not check for this problem.

One More Time..................

You obviously don't understand or didn't read my post. I DID NOT re-wire the circuit. I added GFCI protection to it. All of the Outlets still have 3 Prong outlets. --- So which part of the NEC Code does adding GFCI protection Break? - When you have your Electrical Inspected, they do not search your house for old appliances with 2 prong plugs.

 

[Speedskater]

I added GFCI protection to it. All of the Outlets still have 3 Prong outlets.

Do all the receptacles have a connected Safety Ground wire back to the panel?

 

[Cut-Throat]

Do all the receptacles have a connected Safety Ground wire back to the panel?

Yes, as installed by the Electrician. I just had him put a GFCI on the ONE Circuit that my stereo gear is on.

I am merely using 2 prong Applicances. Like my Old Fisher Tube Receiver etc.

 

[Cut-Throat]

I run "balanced" power in the rack.

60VAC (differential) on both the hot and neutral leads, referenced to Earth, and Earth continuous back to the breaker panel.

The Equitech has GFCI outlets, all my gear comes off it, whether two or three pronged plugs.

Some gear that hums from a standard outlet - an old guitar amp, an old active crossover, as examples - go silent when powered through the Equitech.

A few more Dollars for Sure ..... What did yours Cost if may ask?

 

[Grandzoltar]

A lot of Avr's and subwoofers come 2 prong just for that ground loop reason. They don't have to be old. But removing a ground pin from equipment engineered with a ground wire as part of its topology is dangerous by the time your gfc outlet gets wind of it from the neutral wire your equipment will be toasted. Some manufacturers even warn you about using cheater plugs.

 

[RayDunzl]

I bought a 1.5Q (Q denotes a higher spec for the transformer) off eBay for about a thousand dollars sold by Shock city Studios as they upgraded.

That was eight or nine years ago.

New ones are quite pricey.

 

[Cut-Throat]

A lot of Avr's and subwoofers come 2 prong just for that ground loop reason. They don't have to be old. But removing a ground pin from equipment engineered with a ground wire as part of its topology is dangerous by the time your gfc outlet gets wind of it from the neutral wire your equipment will be toasted. Some manufacturers even warn you about using cheater plugs.

My gear all has fuses which protects them. The GFCI was to protect people. But the GFCI is quicker than a circuit breaker, which is all a 3 Prong Plug depends on. Where did you hear that a GFCI was slower than a circuit breaker? --- Seriously? Manufactures warn you because the Lawyers told them to. Where do you guys hear this stuff?

"
GFCI Operation
When GFCI outlets detect even a relatively small imbalance, a circuit is tripped and the outlet immediately stops the flow of electricity. Working faster than a circuit breaker, GFCIs are designed to operate before electricity can affect your heartbeat - in as little as one-thirtieth of a second."

 

[cjm2077]

I'd rather replace whatever component isn't grounded properly. Floating everything is not solution, it's just a band aid. If that means getting rid of some piece of equipment you have an attachment too, that's too bad.

 

[Cut-Throat]

[

I'd rather replace whatever component isn't grounded properly. Floating everything is not solution, it's just a band aid. If that means getting rid of some piece of equipment you have an attachment too, that's too bad.

Except that is not the problem at all. And you really don't understand what a Ground Loop is. It has nothing to do with a component that isn't grounded properly. I'd explain it to you, but it would just confuse you.

You probably have a Ground Loop in your system, and just not aware of it. Because you are using less sensitive speakers than mine (115db). And may have shorter interconnect runs than I do. Or have gotten used to the slight Hum (I've been over to other Audio People's house and their Hum, bugs the hell out of me). -- So, yes I could get rid of my very sensitive Oris Horns and I would not hear the Hum - But it would still be there and it would not sound near as good as my horn speakers with SET amps. - Like I said, I have a much safer solution that is quiet.

 

[kach22i]

I run "balanced" power in the rack.

60VAC (differential) on both the hot and neutral leads, referenced to Earth, and Earth continuous back to the breaker panel.

The Equitech has GFCI outlets, all my gear comes off it, whether two or three pronged plugs.

Some gear that hums from a standard outlet - an old guitar amp, an old active crossover, as examples - go silent when powered through the Equitech.

Interesting, I read in another forum a slightly different opinion about multiple grounds.

POST #33
https://whatsbestforum.com/threads/my-clean-power-adventures.28053/page-2

The key to why the electrical service box is connected by a heavy copper wire to the incoming cold water pipe is the concept of bonding. Bonding is required by the electrical code in my area and most, I think. See this Wikipedia discussion of electrical bonding.

On the grounding question, all items fed electricity from the service box should be grounded to the service box and that box should in turn be grounded to a single stake in moist ground very near the service box. Multiple grounding stakes would be counterproductive and possibly unsafe since they might have slightly different potentials to ground.

I want to upgrade the service to my house and have a dedicated panel just for the stereo. You don't want to know how I have it temporarily hooked up. I've been without my stereo for several years (long story), just could not wait any longer.

I am not an expert on this topic, just here to learn, NOT a quote of my own post above.

 

[Cut-Throat]

Interesting, I read in another forum a slightly different opinion about multiple grounds.

POST #33
https://whatsbestforum.com/threads/my-clean-power-adventures.28053/page-2


I want to upgrade the service to my house and have a dedicated panel just for the stereo. You don't want to know how I have it temporarily hooked up. I've been without my stereo for several years (long story), just could not wait any longer.

I am not an expert on this topic, just here to learn, NOT a quote of my own post above.

You don't want multiple grounds. But, whatever you do, get a Licensed Electrician to wire your house and have it inspected. Tell him you want a dedicated circuit for your Stereo Gear. One circuit is plenty. Put a GFCI on that circuit. Then whatever you decide to do down the road will be an option for you.

 

[cjm2077]

[


Except that is not the problem at all. And you really don't understand what a Ground Loop is. It has nothing to do with a component that isn't grounded properly. I'd explain it to you, but it would just confuse you.

You probably have a Ground Loop in your system, and just not aware of it. Because you are using less sensitive speakers than mine (115db). And may have shorter interconnect runs than I do. Or have gotten used to the slight Hum (I've been over to other Audio People's house and their Hum, bugs the hell out of me). -- So, yes I could get rid of my very sensitive Oris Horns and I would not hear the Hum - But it would still be there and it would not sound near as good as my horn speakers with SET amps. - Like I said, I have a much safer solution that is quiet.

So what electrical systems have you designed? Because the ones I have don't have ground issues.

You also sound very attached to your equipment. Maybe a bit beyond rationality. Maybe try a different amp and see if the hum goes away. I know it might be less magical for whatever SET reason, but you could try.