ground hum when I touch anything metal

jrfivestar · September 20th, 2008, 10:31 AM

UPDATE: I originally had a bridge pickup which had a ground lug at the plate and was tied into the volume pot per Fender. Since then I've switched out that pickup for an SCN with no changes.

As far as the shielding I added that per other information on grounding/shielding.

It is driving me crazy as my other guitars don't have the problem at all, so I know it is not the electrical outlets, amp, cable etc.

Oh, I didn't run a ground from the plate this time around and again same noise.

HELP PLEASE!!!

I am at the end of my first Tele guitar project and with strings attached I figured I would try the electronics out.

The sound is fine but whenever I touch the volume, tone, or anything metal I get a grounding hum and it ain't a good tune.

I lined the cavities with stickyback copper from Stu-Mac, removed and resoldered all my gounds and all of my connections. I even added a ground to the body in the control panel cavity and moved my jack plug ground to the tone pod.

Any help would be greatly appriciated.

Thanks....

feeder · September 20th, 2008, 10:38 AM

Funny, it's always the other way around for me, the hum diminishes when I touch the the control knobs (same goes for, say, touching an overdrive pedal w/ my bare foot--grounding everything to myself, I suppose?)

Astro1176 · September 20th, 2008, 10:51 AM

Did it do this before you did the shielding? I had an unshielded guitar, and it was like feeder's: it buzzed a bit and stopped if I touched the guitar. I have shielded my guitar with aluminium sticky back tape, which seems to have reduced the overall noise, and I was surprised that it no longer changes when I touch it, that buzz has pretty much gone.

Part way through my shielding project, I think it was doing the same as yours, buzzing more when I touched the strings or metal, but this was when I hadn't finished earthing all the cavities. I don't quite understand why it buzzed more, but I would check with a multimeter that all the cavities and all the seperate bits of tape in each cavity are earthed. It might be an idea to check for earth loops too (see if there are 2 ways to get to earth from any of the cavities or parts) - I don't know much about earth loops except that they are bad and can make hums and noise worse.

Amby · September 20th, 2008, 10:56 AM

Have you checked that you haven't got the hot and ground reversed, say at the output jack?

yegbert · September 20th, 2008, 11:00 AM

Maybe a bridge pickup installed with the lead that's attached to the pickup baseplate "reversed" (going to the switch instead of the pot bottom / ground), yet the baseplate is also grounded (typically via pickup mounting screws) to the bridgeplate?

reddogbass · September 20th, 2008, 11:39 AM

The only time I've had this happen is when I didn't solder the "grounded leg" of the volume pot to ground.

JasonRobert · September 20th, 2008, 11:50 AM

Check that something isnt wired backwards, such as the pickups and output jack. Also check that you dont have any bad solder joints on any of the grounds.

andrewb · September 20th, 2008, 12:20 PM

swap the wires on the jack...

jrfivestar · September 21st, 2008, 01:07 PM

OK, I did switch the jack wires around and that worked and stopped the ground hum upon touch of any metal. I also added a ground wire from the bridge plate as I did get noise when I tapped the plate and the bridge.

No I'm working on a problem which I wasn't aware of, nothing from the neck pickup. I resoldered the connetions including all grounds as a pile of solder isn't appealing to me and checked the switch location per a standard Tele schematic. Since I strung it up to I hope I can remove the pickup without removing the strings. Haven't done before.

Thanks for everyones help......

JasonRobert · September 21st, 2008, 02:02 PM

Quote:

Originally Posted by jrfivestar

No I'm working on a problem which I wasn't aware of, nothing from the neck pickup. I resoldered the connetions including all grounds as a pile of solder isn't appealing to me and checked the switch location per a standard Tele schematic. Since I strung it up to I hope I can remove the pickup without removing the strings. Haven't done before.

sorry I dont quite understand... does your neck pickup not work anymore, and you want to get it working again? or do you want to take the neck pickup out and have esquire wiring?

Astro1176 · September 21st, 2008, 03:34 PM

ummm - swapping wires on the bridge jack around and so on at random until the buzz goes away is not really good practice, the earths are there for safety and to keep you alive as well as reducing hum. You should thoroughly check the circuit and see that it is wired correctly, or take itto an expert who can rewire it safely and correctly for you.

jrfivestar · September 21st, 2008, 09:41 PM

Quote:

Originally Posted by JasonRobert

sorry I dont quite understand... does your neck pickup not work anymore, and you want to get it working again? or do you want to take the neck pickup out and have esquire wiring?

No Esquire wiring. I had a problem with a ground hum when I would touch any metal parts. That was fixed by rewiring the jack plug as it must have been reversed.

Now that I have it strung up I was able to test the sound and the neck pickup doesn't work. I had checked the solder connections which seem ok.

I've got the check the switch to make sure I'm on the correct pole.

jrfivestar · September 21st, 2008, 09:44 PM

Quote:

Originally Posted by Astro1176

ummm - swapping wires on the bridge jack around and so on at random until the buzz goes away is not really good practice, the earths are there for safety and to keep you alive as well as reducing hum. You should thoroughly check the circuit and see that it is wired correctly, or take itto an expert who can rewire it safely and correctly for you.

No I must have had the jack wiried incorrectly because when I changed them the gound hum went away and the bridge pickup sounds great but the neck pickup doesn't work. So now I'm going to check the switch and make sure that the correct pole is being used.

Thanks,

jrfivestar · September 21st, 2008, 09:45 PM

Quote:

Originally Posted by andrewb

swap the wires on the jack...

Thanks, this answer resolved my ground hum when I touched any metal parts.

Thanks for your help, John

jivetrain · September 21st, 2008, 11:11 PM

just to be sure, i think your guitar should have one white wire and one black one wired to the output jack. the white wire should be attached to the lug that flares outward at it's end in sort of a circular shape, while the black wire goes to the plain lug that has the 'normal' flat edges.

if that doesn't make sense, the top lug visible at the top of the photo receives the white wire, while the lower one receives the black. i'd double check to see if you have it this way.

September 20th, 2008, 10:31 AM	#1 (permalink)
jrfivestar NEW MEMBER! Join Date: Sep 2008 Location: Plymouth, MA Age: 51 Posts: 7	ground hum when I touch anything metal UPDATE: I originally had a bridge pickup which had a ground lug at the plate and was tied into the volume pot per Fender. Since then I've switched out that pickup for an SCN with no changes. As far as the shielding I added that per other information on grounding/shielding. It is driving me crazy as my other guitars don't have the problem at all, so I know it is not the electrical outlets, amp, cable etc. Oh, I didn't run a ground from the plate this time around and again same noise. HELP PLEASE!!! I am at the end of my first Tele guitar project and with strings attached I figured I would try the electronics out. The sound is fine but whenever I touch the volume, tone, or anything metal I get a grounding hum and it ain't a good tune. I lined the cavities with stickyback copper from Stu-Mac, removed and resoldered all my gounds and all of my connections. I even added a ground to the body in the control panel cavity and moved my jack plug ground to the tone pod. Any help would be greatly appriciated. Thanks.... Last edited by jrfivestar; September 20th, 2008 at 11:54 AM. Reason: Additional information

September 21st, 2008, 11:11 PM	#15 (permalink)
jivetrain Tele-Meister Join Date: Jun 2006 Location: iowa Posts: 459 4 Photos	just to be sure, i think your guitar should have one white wire and one black one wired to the output jack. the white wire should be attached to the lug that flares outward at it's end in sort of a circular shape, while the black wire goes to the plain lug that has the 'normal' flat edges. if that doesn't make sense, the top lug visible at the top of the photo receives the white wire, while the lower one receives the black. i'd double check to see if you have it this way. Last edited by jivetrain; September 21st, 2008 at 11:49 PM.

September 20th, 2008, 10:38 AM	#2 (permalink)
feeder TDPRI Member Join Date: Sep 2008 Location: Minnesota now, New Zealand soon Posts: 31	Funny, it's always the other way around for me, the hum diminishes when I touch the the control knobs (same goes for, say, touching an overdrive pedal w/ my bare foot--grounding everything to myself, I suppose?)

September 20th, 2008, 10:51 AM	#3 (permalink)
Astro1176 TDPRI Member Join Date: Aug 2008 Location: UK Posts: 98 17 Photos	Did it do this before you did the shielding? I had an unshielded guitar, and it was like feeder's: it buzzed a bit and stopped if I touched the guitar. I have shielded my guitar with aluminium sticky back tape, which seems to have reduced the overall noise, and I was surprised that it no longer changes when I touch it, that buzz has pretty much gone. Part way through my shielding project, I think it was doing the same as yours, buzzing more when I touched the strings or metal, but this was when I hadn't finished earthing all the cavities. I don't quite understand why it buzzed more, but I would check with a multimeter that all the cavities and all the seperate bits of tape in each cavity are earthed. It might be an idea to check for earth loops too (see if there are 2 ways to get to earth from any of the cavities or parts) - I don't know much about earth loops except that they are bad and can make hums and noise worse.

September 20th, 2008, 10:56 AM	#4 (permalink)
Amby Tele-Meister Join Date: Nov 2007 Location: Stirlingshire, Scotland Age: 61 Posts: 244	Have you checked that you haven't got the hot and ground reversed, say at the output jack?

September 20th, 2008, 11:00 AM	#5 (permalink)
yegbert Friend of Leo's Join Date: Sep 2004 Location: Clinton, Maryland (US) Age: 54 Posts: 4,857 85 Photos	Maybe a bridge pickup installed with the lead that's attached to the pickup baseplate "reversed" (going to the switch instead of the pot bottom / ground), yet the baseplate is also grounded (typically via pickup mounting screws) to the bridgeplate?

September 20th, 2008, 11:39 AM	#6 (permalink)
reddogbass Tele-Holic Join Date: Aug 2006 Location: Portland, Oregon Age: 62 Posts: 603 5 Photos	The only time I've had this happen is when I didn't solder the "grounded leg" of the volume pot to ground.

September 20th, 2008, 11:50 AM	#7 (permalink)
JasonRobert Tele-Holic Join Date: Dec 2007 Location: Paddock Wood, Kent, England Posts: 569	Check that something isnt wired backwards, such as the pickups and output jack. Also check that you dont have any bad solder joints on any of the grounds.

September 20th, 2008, 12:20 PM	#8 (permalink)
andrewb Tele-Meister Join Date: Jul 2008 Location: sydney Posts: 293	swap the wires on the jack...

September 21st, 2008, 01:07 PM	#9 (permalink)
jrfivestar NEW MEMBER! Join Date: Sep 2008 Location: Plymouth, MA Age: 51 Posts: 7	OK, I did switch the jack wires around and that worked and stopped the ground hum upon touch of any metal. I also added a ground wire from the bridge plate as I did get noise when I tapped the plate and the bridge. No I'm working on a problem which I wasn't aware of, nothing from the neck pickup. I resoldered the connetions including all grounds as a pile of solder isn't appealing to me and checked the switch location per a standard Tele schematic. Since I strung it up to I hope I can remove the pickup without removing the strings. Haven't done before. Thanks for everyones help......

September 21st, 2008, 03:34 PM	#11 (permalink)
Astro1176 TDPRI Member Join Date: Aug 2008 Location: UK Posts: 98 17 Photos	ummm - swapping wires on the bridge jack around and so on at random until the buzz goes away is not really good practice, the earths are there for safety and to keep you alive as well as reducing hum. You should thoroughly check the circuit and see that it is wired correctly, or take itto an expert who can rewire it safely and correctly for you.