why does my guitar make noise when i dont have my hands on the strings?

[snookelputz]

As soon as you plug in and turn on the whole system becomes one big ground circuit which may or may not include you touching the strings. The hum is either from a less-than-perfect ground or else it is 60 cycle hum or both. It sounds the same when the volume knobs are off because the ground is poor, not because the is some amplification problem.

[Biff]

As soon as you plug in and turn on the whole system becomes one big ground circuit which may or may not include you touching the strings. The hum is either from a less-than-perfect ground or else it is 60 cycle hum or both. It sounds the same when the volume knobs are off because the ground is poor' date=' not because the is some amplification problem. [/quote']

 

+1 .. When you touch the amp or the strings, you act as a more effective ground than what the wiring in your guitar and the cord to the amp can offer (sounds fairly dangerous and sometimes with faulty equipment or electric connections it is)..

[orac02]

I had a similar problem with my Yamaha 112v (single coil). It was all earthed OK but still hummed, but- I noticed when I put the guitar down it reduced.

 

The problem I believe is that YOU are not earthed and when you put the guitar on your lap, or againt you it increases the pickup.

You can earth yourself (you can get wrist straps ) so as you say when you touch your (earthed ) amp it is reduced.

When you touch the string you are earthed through them.

 

It suggests to me that your guitar is picking up more background noise than you would expect from a guitar with humbuckers.

[snookelputz]

I had a similar problem with my Yamaha 112v (single coil). It was all earthed OK but still hummed' date=' but- I noticed when I put the guitar down it reduced.

 

The problem I believe is that YOU are not earthed and when you put the guitar on your lap, or againt you it increases the pickup.

You can earth yourself (you can get wrist straps ) so as you say when you touch your (earthed ) amp it is reduced.

When you touch the string you are earthed through them.

 

It suggests to me that your guitar is picking up more background noise than you would expect from a guitar with humbuckers.[/quote']

 

Makes me think I would also want to test all three legs of the power circuit at the wall outlet. The thing with the amp catches my attention. Ah, you are using a 3 prong plug, right? No pigtail adapter? Check for proper voltage, polarity and earth. And, last, my only 20 foot cord hums in every amp I plug into IF the guitar has high output pickups or if you dime controls. Doesn't do it with any other cable. Cheap cable, I suspect they skimped a guage on the ground wire which is the skinniest single strand of solid core wire I ever saw inside a patch cord.

[orac02]

snookelputz

Yes a three pin earthed lead.

Earthing myself by 1) touching the earthed amp 2) touching anything else earthed 3)through an earth lead from the mains

(dont do this if you are AT ALL unsure what you are doing) 4) through the earthed metal bits on the guitar----all sorted the problem.

Hence my conclusion that it was your body being UN earthed was the problem.

 

Having decided I knew what it was I was happy to ignore it. I then subsequently changed the pickups to fender noiseless type

and the hum virtually disappeared.

 

Its not noticable on any of my guitars with humbuckers.

[Dave]

Did it hum before you changed pickups or not? If it didn't, you have a wiring problem. None of the Gibson schematics show the color codes for the wiring from the pickup switch, so you are going to have to clue us in on which colors go to which contact on the switch for us to give you accurate information. If you do that, I think we can help.

[carverman]

Heres a question.. when i wire my pots together for grounds.. do they go THROUGH the lug i bend down? or over it?

 

 

 

From what I can see you have 4 colours of unshielded wire going to your 3-way and then

to the output jack, unless you have foil shield with a bare ground wire that is not

connected to anything. This is what I mentioned previously. The bare shield wire

must be connected at the 3 way and the pot cases and the lug on the output jack.

If the existing wire is not foil with a separate ground wire,You need to replace the unshielded

wire with either a 3 conductor or 4 conductor shielded (Belden). Yo can get that from

Stew=Mac #1818 or the wire kit #4575. However shipping charges may be expensive

for just wire, so if you can't get it locally through a supplier, take some aluminum foil and

a bare wire and wrap the jacket of the existing multi-conductor wire, tape it so the

foil stays on and then solder the ends of the bare wire to the 3 -way and the pot cases

AND the jack.

[carverman]

Okay' date=' I think the hum is normal. Here's what I'm thinking:

When you use your tele and turn down the knob, the hum goes away because you're used to the loud hum from the single coils. With the les paul, when you turn down the volume you it only gets a little quieter. I think it's all relative to what the amount of hum was.

[/quote']

Well my Epi LP hummed like crazy because the factory workers decided to use Unshielded

wire on the runs from the pots to the 3 way and back to the jack..this is silly!

Why bother with sheilding p-up wires if you are not going to do a complete and

proper shielding job on a 500k to 1 megohm input impedance to an amp.

 

I replaced my factory wiring job with a shielded wire set where both ends are

connected to the pots, 3 way and jack..and the hum has disappeared.

These are humbuckers...not single coils, so there should be very little hum to begin with.

[The_Sentry]

bad ground +1

 

Yup.... You may also want to pull off the backplate behind the pots and make sure the harness is locked in securely. You've definitely got a loose wire, or a bad connection.

[valriver40]

i bought a es 175 and have the same hum problem . looks like its re-wire time with shieded wire i guess.

[bug music]

Heres a question.. when i wire my pots together for grounds.. do they go THROUGH the lug i bend down? or over it?

Shouldn't matter as long as the lug, the wire, and back of the pot are all connected together. They are all the same point electrically.

 

The only thing I see there in your pictures, is the gray cable to the selector looks like a shielded cable( I can see some of the silver/blue foil sticking out of the end). If you cut back a little insulation on the gray cable you will see some braided "shielding wire" around the other four conductors. Twist about 1/4 inch of the braid together, and solder a wire to it, then solder the other end of that wire to any ground point.

 

An ungrounded shielded cable makes an amazing antenna for noise. If I am using shielded cable, I always ground one end of the shield, this may be part of your noise problem.

 

Hopefully this helps.

 

EDIT : Damn Carverman you're a fast typist, beat me to it while I was still typing. :)

 

- Jay