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How do you shield/ Earth guitar

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A recurrent problem I've had with guitars over the years is Earthing/ shielding.

An example:

I plugged my dual-humbucker guitar into a newly serviced amp (absolutley quiet when no guitar is plugged in). After I plug in, as I turn the gain up, the amp remains pretty quiet...until I take my hands off the guitar...then hiss galore. Touch anything metal, and she goes really quiet again. Touch metal on guitar -> quiet. Take hands off -> hiss.

1. Is this normal?

2. How can I get it to just stay as quiet as if was touching it the whole time?

3. If you wanted to Earth/ shield your guitar to the level of overkill, what can you do?

Any help greatly appreciated. I want to be able to do it myself, because it has happened with most of my guitars at some time or another.

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Yes, but where does the ground-wire go to? On a guitar, where is ultimately the Earth/ ground?

I haven't read Ben Amos' link yet, it was too heavy for the late hour. I'll need to wait for a weekend again. It's a decent-sized project.

Remember gents that this problem is only noticeable at full-tilt gain. Under normal conditions she's fine. So it's not a problem unless I'm going for high-gain metal at moderately loud volume, gain up on lead channel. Playing clean it's unnoticeable.

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You do need to read that link - but don't let it scare you too much.

I'm not sure I understand your question but the ground is attached to the screened part of your cable. There is a ground wire that goes to your bridge too (hence your strings).

That site will explain how to arrange the earths so that you don't get ground loops, too.

Good luck - play loud, but play careful.

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I'm printing off that link to paper as we speak, so I can read if I get quiet at work. All shall be revealed, huh? It's pretty interesting to me, so I'll enjoy reading it. The guy's style is entertaining, too.

There we go, 12 pages of informative goodness.

BTW, played too loud. My wife is advertising my "big" amp for sale! :crying2: Oh well, I get to buy an Epi Jnr, which could be cool. But I'll need a Metal Zone pedal or similar to go with it to get distortion at lower, household friendly volumes.

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I am following those instructions on guitar nuts at the moment while I upgrade my Tele. There is not too much to worry about but you do need to do some soldering.

I have been taking quite detailed photo's for my own reference and I will post them up in a few days once I have finished with my comments.

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Yes, but where does the ground-wire go to? On a guitar, where is ultimately the Earth/ ground?

I haven't read Ben Amos' link yet, it was too heavy for the late hour. I'll need to wait for a weekend again. It's a decent-sized project.

Remember gents that this problem is only noticeable at full-tilt gain. Under normal conditions she's fine. So it's not a problem unless I'm going for high-gain metal at moderately loud volume, gain up on lead channel. Playing clean it's unnoticeable.

I had the same problem that RB mentioned with my tele. The wire that grounded the bridge wasn't making a connection. It would hum until I touched the control plate, knobs, etc... It was a simple matter of making sure the ground wire was against the bridge.

The earth ground is the shield (sleeve) wire of the instrument cable.

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I had the same problem that RB mentioned with my tele. The wire that grounded the bridge wasn't making a connection. It would hum until I touched the control plate, knobs, etc... It was a simple matter of making sure the ground wire was against the bridge.

The earth ground is the shield (sleeve) wire of the instrument cable.

Did you fix the ground wire to the bridge or did you just screw the bridge on with the wire floating underneath?

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Floating wire underneath. I suppose I could have ground off some chrome and soldered it but I was too lazy. I can't remember if the wire was long enough to move the bridge around if it's soldered.

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I had the same problem that RB mentioned with my tele. The wire that grounded the bridge wasn't making a connection. It would hum until I touched the control plate, knobs, etc... It was a simple matter of making sure the ground wire was against the bridge.

The earth ground is the shield (sleeve) wire of the instrument cable.

It's great to hear the exact same prob described so well.

My Tele is under warranty, and the store owner had a look and said it seemed OK, so it's off with a Tech at the moment.

However it has been such a recurrent problem for me that I think it is worth knowing how to rectify. That's for all your insights, everyone. :) There is another guitar having the same issue, so I'll read up and try the stuff out on that one.

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You guys are exactly right. I took off the bridge and there is a piece of wire just dangling there. I suspect that I displaced it from the bridge when I took the pick guard off before. It probably pulled on the wire. Since I have it pulled apart, I might actually solder it to the bridge. I would have thought they should have done that when they made it. I tried taping it but it needs to be a firm contact.

While looking for loose wires and problems elsewhere I managed to stop the bridge pickup from working also. Hopefully this will fix both problems. Fingers crossed.

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OK, so I didn't end up soldering it, but I ended up leaving it floating but in contact with the bridge like fly135 did. That didn't fix it the buzz. So I resoldered the plug. Still a buzz.

I had managaed to disconeect a pickup, so I resoldered that and it works now, but the Earthing problem persists. Where do I look next? I'm thinking I'll have to put it into the shop.

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Do you have anything like an ohmmeter, or a continuity checker? If possible, I think it would be a good idea to check the connection between the bridge and the jack in your guitar. They should show less than an ohm of resistance (mine reads 0.8 ohms between any string and the jack). If you succeeded in making such a connection by moving that wire, then you can move on, knowing that nothing's been overlooked. Until that's been established, I'd still be wondering about whether pressure alone was making for a good contact, and whether the other end has a good solder connection to ground.

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Well, since I have nothing to lose, I might jiggle that wire from the back of the guitar. I don't feel like removing the Tele-style bridge and strings again. I was pretty careful though. The wire only has to touch the back of the chrome plate, right?

I removed the Earth wire and resoldered it to the jack plug. It didn't fix it so I unsoldered it and soldered it again, but to another metal part of the socket (ie a fresh bit of metal, fresh solder, but same part. I didn't connect it to the wrong part or anything). Just to check, solder is a conductor, right? I mean if you had some solder between the wire and the socket, you'd still get current wouldn't you? Or is the solder just a glue?

By the way the Earth wire goes from the bridge to the back of a pot and from there to the jack. So if the back of the pot has a dry joint, I probably wouldn't want to re-touch it because it has so many wires attached.

I don't have a continuity tester or ohmeter. But I might invest in one.

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The wire only has to touch the back of the chrome plate, right?

Firm metal-on-metal contact with anywhere on the bridge should do, assuming it's made the same way as most Tele (or other) bridges.

I removed the Earth wire and resoldered it to the jack plug. It didn't fix it so I unsoldered it and soldered it again, but to another metal part of the socket (ie a fresh bit of metal, fresh solder, but same part. I didn't connect it to the wrong part or anything). Just to check, solder is a conductor, right? I mean if you had some solder between the wire and the socket, you'd still get current wouldn't you? Or is the solder just a glue?

Solder is both glue and a conductor.

By the way the Earth wire goes from the bridge to the back of a pot and from there to the jack. So if the back of the pot has a dry joint, I probably wouldn't want to re-touch it because it has so many wires attached.

I don't have a continuity tester or ohmeter. But I might invest in one.

The way almost all guitars are wired is that all connections destined for ground meet at one of the pot casings. It's not necessarily the best solution, but it's almost always the most convenient soldering surface. Then a wire connects that pot casing to one of the jack connectors (the one towards the outside, rather than the one that connects with the tip of the plug), which is where actual ground should be available. I say "should be" because the guitar has to rely on the amp to connect to ground -- one wire in your guitar cord carries the signal, the other carries ground. Your cable isn't likely to screw this up (either it will work, or it won't, generally speaking), but it is possible for something at the amp end to do so. Like if you used an adapter to plug your amp's 3-prong plug into a 2-prong outlet or extension cord. This is not only a bad idea from a sonic perspective, it could literally kill you under some circumstances (amp failure and/or messed up wiring), so definitely DO make sure that your amp is using all 3 prongs!

I'm assuming that you've played with other amplifiers, and at other locations... does your guitar hum in the same way regardless of amplifier and location?

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I'll double check with another amp. I tried with a new amp I bought which I am sure is faulty, so that was no good. Even my good guitar had problems through that amp. I am wondering if the house has Earthing probs. Does Earth from guitar go to amp go to bottom Earth plug of electrical socket?

I'll retest and post again. Thanks for your help.

Is it possible for Earth not to work because of your house's electricity? ie that the house's Earth wiring itself is faulty?

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Does Earth from guitar go to amp go to bottom Earth plug of electrical socket?

I am no expert but my plugs are only 2 pin so there is no way that my gear earths through the socket.

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How old is your house? A while back I had the old fuse box renewed in my aging weatherboard house with a modern Earth-leakage breaker setup. The electrician drove a two metre long earthing stake in to make a new Earthing path. He said that he always does that with ELB installations as the Earthing path in many older houses in Australia is not reliable.

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I am wondering if the house has Earthing probs. Does Earth from guitar go to amp go to bottom Earth plug of electrical socket?

.............

Is it possible for Earth not to work because of your house's electricity? ie that the house's Earth wiring itself is faulty?

Bad wiring can cause mysterious hum problems, but the more compelling argument for checking it is for your own safety. Back when outlets only had 2 prongs ("hot" and "cold" but no true ground), it was normal for the metal chassis that radios and amplifiers were built into, to be connected to "cold," a prong which was supposed to be at roughly zero volts. The only problem with this was that "cold" wasn't always as advertised. If someone managed to fit the plug in backwards, for example (pretty easily done with 2-prong US style plugs), the chassis might them be at 117VAC, and anyone coming into contact with screws or other conductive items that were connected to the chassis, might receive a serious, or even fatal, shock. Fault conditions within the electronic item could also do the same, as could problems with the electricity provider's equipment.

This situation was resolved by adding the third prong, and requiring that it have a direct, nearby connection to the Earth. Electrical fault conditions which involve the Earth are mostly limited to the immediate vicinity of lightning strikes, making it far more reliable than your local utility provider. And by requiring that chassis be connected to the Earth, rather than to "cold," situations such as I referred to earlier became far less likely. In the event of equipment malfunction, like a charged wire coming loose and touching the chassis, it became much more probable that you'd simply blow a fuse, than that you'd be electrocuted by touching it.

If one uses a 2-prong adapter to plug things in, or if one plugs into an incorrectly wired outlet, all bets are off, you're back to 1940s safety conditions. For this reason, some websites will advise guitarists to carry an electrical outlet polarity tester with them, and to always use it before plugging into a particular outlet for the first time. (Testers are no larger than a normal electrical plug, and in the US can be had for under $10.) There's a good writeup on that, and other electrical safety considerations for guitarists, here: GuitarNuts.com - Shock Hazards

Some might want to use a ground fault circuit interrupter (GFCI) when they plug in, this is the same thing you find on outlets in a lot of recently constructed US bathrooms, where you have a couple of buttons for testing the outlet's safety. GFCIs have sensing mechanisms built in which will notice if some of their power is going to ground in an unexpected way -- like through a guitarist, for example. If so, power is shut off within a fraction of a second. GFCIs Fact Sheet Portable GFCIs, which can be used with any properly wired outlet, start at about $12 in the US. Tower Shock Buster Portable GFCI (Saltwater Aquarium Supplies > Miscellaneous > GFCI Cords & Grounding Probes )

Sorry for going miles off-topic, but it seemed like something that readers here should know about. Some of it may sound kind of paranoid, but those of us who repair 400 volt tube amps and the like tend to think about this sort of thing more than most people.

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How old is your house? A while back I had the old fuse box renewed in my aging weatherboard house with a modern Earth-leakage breaker setup. The electrician drove a two metre long earthing stake in to make a new Earthing path. He said that he always does that with ELB installations as the Earthing path in many older houses in Australia is not reliable.

Wow! What a specific reply! Yeah, we live in an aging weatherboard house too! We got a new safety switch fitted when we bought the house but the electrician did mention we'd need a new "power board" at some stage. The one we've got would be over 40 years old.

P-90, yes the problem occurs with different guitars, different amps and in different parts of the house, which is leading me to suspect that the house's ground isn't working. So it looks like I'm stuck with it until we spend the money to get a new power board. It may even fix the hum/hiss from the television I hope!

Oh, and if it is relevant, I am pretty sure everything we've got is 3 prong, with the middle/ lower prong as earth.

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