Cheap fix on Ground Loop

[JL Sargent]

Those homes are violating safety codes

 

Not if it was built before 1965 in most cases. They are grandfathered in under the old codes and exist all over the US LEGALLY.

[babadono]

My point and I believe Don's also is that if a piece of equipment has a 3 prong power cable, the 3rd prong is meant to go to ground. For whatever reason the manufacturer deemed it is necessary. Do not defeat it on a permanent basis to get rid of a ground loop.

[Don Richard]

 

Those homes are violating safety codes

 

Not if it was built before 1965 in most cases. They are grandfathered in under the old codes and exist all over the US LEGALLY.

 

 

Until electrical work is done on the house, then an inspection is necessary. At least in my area it is.

[bhenry]

Actually, you used to be able to use the cold water as a ground until plastic plumbing came around (non-conductive, thus when/if a water pipe fails and someone were to replace it with plastic you would loose your ground), we now have to run a ground wire from the service back to the water meter then bond (jumper from the street side across to the house side of the water meter in case the water meter is ever removed) the water meter. Then install two ground rods also with a grounding conductor from the service.

[derrickdj1]

I'm sorry and this is only my HO but you cannot get a pair (or 1 for that matter) of high quality (good freq response down to 20Hz and at low distortion levels) audio transformers for 6 bucks.

 

I measured the distortion level at near subwoofer and MLP today.  Here are the numbers:

 

10Hz              less than 1 meter to speaker  25%                  MLP    12.67%

 

20Hz                                                             4.59%                            8.84%

 

50Hz                                                            1.23%                             0.47%

 

100Hz                                                          0.67%                             1.23% 

 

The subs are tuned to around 21 Hz and the 10 Hz distortion level of 25/12.67% is not unexpected since I am not trying to reproduce those frequencies. The 10 Hz measure was taken with one of the vented subs. The 100 Hz distortion number of 0.67 and 1.23% are opposite of all the other reading since the close mic measured lower.  This is also not unusual since the system is XO at 50 Hz.  The 100 Hz measure represents the mains and sub at the MLP.  The distortion readings are very good for the system in the working range for the subwoofers using the ground loop isolator.  For 20 Hz and above the system wood get a very good rating from database.com CEA standards for subwoofers.  Distortion figures derived from Dayton Omnimic.

Edited December 14, 2014 by derrickdj1

[Beechnut]

Thanks for sharing your results with us Derrick. So I guess there is no fear on its ability to pass the signal through with no noticeable degradation in the frequency response.

 

Great find!

[NOSValves]

I see you can find no proof to support your claim....okay I'm clear

Yes, you are clearly wrong.

I see I'm wrong because Don says I'm wrong even though he can not conjure up any proof to support his alarmist claim...that seems reasonable to me!

[Marvel]

Our house was built in 1962, so the majority of the wiring is rated at 60 deg. C. Won't handle the current... We had a couple of things done when we moved in last year, which meant the electrician had to correct the circuits he worked on. The kitchen got GFCIs put in the break box, for example. However, the whole house didn't have to be upgraded, only the circuits he worked on.

 

Bruce

[Don Richard]

I see I'm wrong because Don says I'm wrong even though he can not conjure up any proof to support his alarmist claim...that seems reasonable to me!

 

So says the "local technician".

[babadono]

Is one death a year acceptable? how about one per month? One a day? What are we talking about here? Like I said before electrocution is a "silly" idea until it happens to someone in your family. What about injuries, fires and property damage? What level of those "accidents" are acceptable? Again if a piece of equipment has a third wire safety ground it is there for a reason. USE IT. The life saved maybe yours.

[babadono]

 

I'm sorry and this is only my HO but you cannot get a pair (or 1 for that matter) of high quality (good freq response down to 20Hz and at low distortion levels) audio transformers for 6 bucks.

 

I measured the distortion level at near subwoofer and MLP today.  Here are the numbers:

 

10Hz              less than 1 meter to speaker  25%                  MLP    12.67%

 

20Hz                                                             4.59%                            8.84%

 

50Hz                                                            1.23%                             0.47%

 

100Hz                                                          0.67%                             1.23% 

 

The subs are tuned to around 21 Hz and the 10 Hz distortion level of 25/12.67% is not unexpected since I am not trying to reproduce those frequencies. The 10 Hz measure was taken with one of the vented subs. The 100 Hz distortion number of 0.67 and 1.23% are opposite of all the other reading since the close mic measured lower.  This is also not unusual since the system is XO at 50 Hz.  The 100 Hz measure represents the mains and sub at the MLP.  The distortion readings are very good for the system in the working range for the subwoofers using the ground loop isolator.  For 20 Hz and above the system wood get a very good rating from database.com CEA standards for subwoofers.  Distortion figures derived from Dayton Omnimic.

 

At what levels are these measurements made? All transformers have properties that make it hard to pass low frequency signals. Low quality/cheap transformers just make it worse. 

[NOSValves]

Is one death a year acceptable? how about one per month? One a day? What are we talking about here? Like I said before electrocution is a "silly" idea until it happens to someone in your family. What about injuries, fires and property damage? What level of those "accidents" are acceptable? Again if a piece of equipment has a third wire safety ground it is there for a reason. USE IT. The life saved maybe yours.

  No even one is not acceptable............ but please show me just "one" with a home audio system setup like I suggested....please show me. If it happens there has to be a record of it some where.......the fact of the matter is a failure so bad that it could fry the inter connecting cables ground conductor would also fry the fuse and most likely fry the fuse before the inter connecting cables grounding conductor could fry... This is all much to do about nothing.

[babadono]

No even one is not acceptable...

Glad we're on the same page on that. I have a document that claims "consumer audio and video equipment"  in a typical year in the USA causes 10 electrocutions, 200 fires which cause 100 injuries, 20 deaths and 30 million in property damage. I am trying to corroborate where these stats. come from.

[derrickdj1]

At what levels are these measurements made? All transformers have properties that make it hard to pass low frequency signals. Low quality/cheap transformers just make it worse.

 

 

I did the test at 75-80db.  With the Omninmic System you can't do real high spl levels doing these tests.  I can most likely push up to 100-105 db without clipping the mic.  The mic uses pseudo nosie and sine waves.  Once Database.com test the Dayton Ultimax sub in the spring I will see what Josh Ricci and crew will report.  I have low distortion in the system with 4 subs (six 18 in. long throw diver) and a ton of overhead with 10,000 plus watts to push them.  I have own this system for a while and would most likely detect a difference in SQ fairly easy since I use it on a daily basis. I am sure distortion data would change if the subs are pushed near the limits as is true of any subwoofer system.  Either way, I am very pleased with the ground loop isolator and can recommended it without hesitation.

 

I have learned over the years on this forum how to get a great system without breaking the bank all the time.  Tranformers are large and obtrusive.  This is just another item that gives consumers more options. Everyone get's to pick their own posion, lol.

Edited December 16, 2014 by derrickdj1

[Paducah Home Theater]

Sales pitch from a company profiting from the sale of such devices..

Peavey sells amps. They don't sell any kind of newfangled ground device that they're trying to sell here, nor are they touting their superiority to other manufacturers that don't include a ground. They mention their high-pot test and the ability to reverse polarity of the bypass cap, but on the generic statements about safety in regards to ground, they give blanket statements that include all manufacturers. There's a reason. They have absolutely no reason to tell you to not defeat the ground other than to maybe not get sued when other folks like you say it's perfectly fine to do so.

If you'd rather hear it from a third party that isn't selling anything:

http://www.epanorama.net/documents/groundloop/why_grounding.html

One thing it mentions that is being overlooked here is that ground protects your equipment to some extent. Bypass it and your stuff gets fried easier.

Edited December 16, 2014 by MetropolisLakeOutfitters

[Paducah Home Theater]

Page 8:

http://www.aes.org/sections/pnw/pnwrecaps/2005/whitlock/whitlock_pnw05.pdf

[derrickdj1]

That was a nice read Mark.  Thanks.

[Coytee]

I wouldn’t even want the theory of a chance.

 

I was once at my father in  laws house.  Short story, he needed a new heating element in his water heater.  No problem…  I can do that.

Find the breaker to the heater and kill it.  I did the “glug glug glug” method where  you quickly pull out the old one and stuff in the new one losing very little (but some) water in the process.  This instead of draining the entire tank.

 

As this happened, I ended up sitting in a bit of water since it had nowhere to go but the floor.

 

I then felt a distinct but on the mild side, shock.

 

Perplexed….  I reached out to touch it again.  (by now, I don’t know if I was trying to unwire the old element, wire in the new element….  I just know that I was sitting in a puddle of water (mild puddle) and was getting shocked every time I touched the darn thing.

Fearing that something was cross-wired, I told the wife to get me a flashlight and then simply go kill the panel to the entire house.

I didn’t want to play Dick Tracy while getting mild (but confirmed) shocks.  I didn’t wire it, I’m not an electrician and don’t like to glow in the dark.

 

She killed the power and I CONTINUED to get shocked as I put it back together.

 

We finally managed to piece it together with nobody getting hurt.

 

Told brother in law (electrician) and he pretty much immediately knew the issue and called the power company.

 

Seems they had one of their power lines out in the woods, snap and was laying on the ground.  My understanding is I became the conduit for those volts that were seeking to go home.  Took them almost two days to fix it as they had to re-string some part of it.

[Paducah Home Theater]

No even one is not acceptable............ but please show me just "one" with a home audio system setup like I suggested....please show me. If it happens there has to be a record of it some where.......the fact of the matter is a failure so bad that it could fry the inter connecting cables ground conductor would also fry the fuse and most likely fry the fuse before the inter connecting cables grounding conductor could fry... This is all much to do about nothing.

http://forums.anandtech.com/showthread.php?t=2139639

Although that was a PC, a stereo receiver could do the exact same thing for the exact same reason.

[NOSValves]

No even one is not acceptable...

Glad we're on the same page on that. I have a document that claims "consumer audio and video equipment" in a typical year in the USA causes 10 electrocutions, 200 fires which cause 100 injuries, 20 deaths and 30 million in property damage. I am trying to corroborate where these stats. come from.

I'm sure some electrocutions and fires do happen via audio/video equipment.....but I'd like to see stats that show them happening from one component grounded and all other components attached to the grounded component lifted.. I bet some percentage of those shocks, fires and deaths happened with grounded power cords but had faulty house wiring or boneheaded users involved. I mean if your system is humming like a beast and has smoke, sparks and fire coming from it and your dumb enough to touch it no amount of 3 wire grounded power cords is going to save you.