Line Conditioner (Ground Loop)
Jul 30, 2007 at 3:55 PM Thread Starter Post #1 of 31

M3NTAL

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I think I might have a ground loop problem possibly.

I've disconnected my source equipment and have just my pre-pro and amp hooked up - when I turn the volume to 12 I get a slight humming. It is a higher freq hum. It sounds like some of the hum bleeds over into the right channel, but most of it is in the left. It is just loud enough to be noticeable.

Would a line conditioner or battery backup help my issue at all?

Thanks
 
Jul 30, 2007 at 4:49 PM Post #2 of 31
Quote:

Originally Posted by M3NTAL /img/forum/go_quote.gif
I think I might have a ground loop problem possibly.

I've disconnected my source equipment and have just my pre-pro and amp hooked up - when I turn the volume to 12 I get a slight humming. It is a higher freq hum. It sounds like some of the hum bleeds over into the right channel, but most of it is in the left. It is just loud enough to be noticeable.

Would a line conditioner or battery backup help my issue at all?

Thanks



If you have powercables using earth wire, cut em off! I have experimented extensively with powercables and find them sound better without earth wire. It might be even the earth wire that introduces earth loops and other nasties into the system.
 
Jul 30, 2007 at 5:18 PM Post #3 of 31
There is a reason that the jack that your equipment has three prongs. Removing the safety ground is never a good idea for equipment that is designed with one in mind.
 
Jul 30, 2007 at 5:22 PM Post #4 of 31
Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
If you have powercables using earth wire, cut em off! I have experimented extensively with powercables and find them sound better without earth wire. It might be even the earth wire that introduces earth loops and other nasties into the system.


Social Darwinism in ACTION! An excellent suggestion to cull the gene pool.
http://www.head-fi.org/forums/showpo...2&postcount=12

FWIW
 
Jul 30, 2007 at 5:36 PM Post #6 of 31
Quote:

Originally Posted by pmkap /img/forum/go_quote.gif
Social Darwinism in ACTION! An excellent suggestion to cull the gene pool.
http://www.head-fi.org/forums/showpo...2&postcount=12

FWIW



Great link pmkap! Thanks for doing all the explaining I was thinking of, but was too lazy to
smily_headphones1.gif
 
Jul 30, 2007 at 8:38 PM Post #7 of 31
pmkap,

The link is fine for basic, no brainer info, but unfortunetly it does not explain what 10's of millions of older home owners who don't have grounds on any of their outlets should do about protecting themselves from all their ungrounded electrical equipment.

Basically, any house built in the US prior to 1970 has all ungrounded outlets. If the electrocution hazard were truly that great due to ungrounded mains, we'd be hearing about a lot more electrocution deaths wouldn't we?

If ungrounded electrical appliances were a major electrocution hazard, hundreds of thousands would be electrocuted every year. Cheater plugs would be illegal and all older home outlets would be required, by law, to be changed over to grounded systems. Finally, no electical appliance would have an ungrounded two prong outlet.

A stat I just pulled of line- Only 411 people died from electrocution in the US in 2001. Most from faulty installed home wiring not faulty appliances.

As Chicken Little says "The sky is falling " .............not.
 
Jul 30, 2007 at 11:15 PM Post #10 of 31
Tin Ears,

I'm not your parent, so its not my place to tell you what is and isn't safe and what steps you should take to maximize your safety. If one lifts the ground, the only time it matters is if, and only if, there is a fault where that safety ground is needed, admittedly a rare situation.
I look at it the same way as having trigger locks on any guns in a house where children may be present. You can look at it any way you choose.

The reason there are still existing ungrounded outlets is that economics trumps safety. So what else is new? All new construction and 'filed' improvements require grounded outlets.

Personally, I've never met a ground loop I couldn't fix with either the techniques outlined by Dan Banquer or the loop breaker from ESP (links provided in the link in my post above). If you can't be bothered, or lack the requisite skills, do whatever you want. Its not my problem.

I'm not interested in how many folks may or may not be electrocuted; I'm really only interested in those that I care about not risking their lives needlessly as ground loops can be fixed, without compromising safety. If your calculus finds it best to use that cheater plug, probability is obviously on your side, then go for it. After trying to understand the logic of your response, I might actually encourage you to lift all the grounds.
tongue.gif
Statistically, it may be best, longterm, for mankind.

Heck, we all do unsafe things. I enjoy prime cuts of beef with their high fat content, even though I know given my age and family history its not overly wise.

As an aside, there is no such thing as a 'cheater plug'. Those plugs are there to provide a grounded socket where none existed prior, as they're supposed to be used to tie that little tag via the cover screw to a grounded box housing the outlet. If one chooses to repurpose those plugs, its not my problem, or concern.

FWIW
 
Jul 30, 2007 at 11:36 PM Post #12 of 31
m3ntal, eliminating the ground might eliminate the hum.

Pmkap and other psuedo electricians (lumped in with the psuedointelectuals that regurgitate what they read in high school level text books and code)

Info from the National Safety Council-

The probabiltiy of death from various activities and events in the US 2003_

Hot weather 1/13,729
Alcohol poisoning 1/10,048
Electrocution 1/9,968
Bike accident 1/4919
Fire 1/1,113
Drowning 1/1,008
Car accident 1/84
Cancer 1/7

The sky is falling the sky is falling. Run Forest, runnnnnn!!!! I have eliminated my ground and the earth will stop spinnning.
 
Jul 30, 2007 at 11:59 PM Post #13 of 31
Quote:

Originally Posted by tin ears /img/forum/go_quote.gif
m3ntal, eliminating the ground will eliminate the hum.

Pmkap and other psuedo electricians (lumped in with the psuedointelectuals that regurgitate what they read in high school level text books and code)

Info from the National Safety Council-

The probabiltiy of death from various activities and events in the US 2003_

Hot weather 1/13,729
Alcohol poisoning 1/10,048
Electrocution 1/9,968
Bike accident 1/4919
Fire 1/1,113
Drowning 1/1,008
Car accident 1/84
Cancer 1/7

The sky is falling the sky is falling. Run Forest, runnnnnn!!!! I have eliminated my ground and the earth will stop spinnning.



I still don't see how wanting to have a safety ground connected is anywhere equal to saying the sky is falling.

I would say it's on par of choosing to properly hydrate yourself to keep from dying from hot weather, or perhaps deciding to not drink alcohol till you are plastered and risk dying from alcohol poisoning, or choosing to not drive that car that was salvaged and decreasing your chances from dying in a fatal collision, or maybe not smoking and decreasing your chances of cancer? Would you call those decisions also acting like chicken little?

As always, risk is a personal decision, and IMHO I would rather properly correct the ground loop than to just lop off the safety ground. And that's my 2yen.
smily_headphones1.gif
 
Jul 31, 2007 at 6:00 AM Post #15 of 31
Why do people keep derailing this thread?

Just set the amplifier up by itself with nothing connected. If the hum remains, it's the amp. If by some chance this has to do with it's earth ground then open up the amp and see if it is a soldered on type or if the earth ground wire is just a nut/bolt type connection. In that case, just undo it for a moment and see if the hum goes away.

If there is no hum with the amp by itself, hook your pre back up. If the hum returns, try eliminating the ground on the audio cable. If that fixes it, but the hum comes back when you connect a source to the pre, then eliminate the ground on that audio cable, too!
 

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