#1
I have just fitted new electronics to my strat, and there is a terrible hum coming from it. It seems to be correctly grounded, with all ground wires soldered to the back of a pot. The output jack is wired the correct way around. When I touch any metal on the guitar the humming goes away completely, even though there is a ground wire soldered to the trem claw.

Does anyone have any ideas what this could be?
Gibson SG
Laney Cub 10
Ibanez SD9M
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#2
have you tried plugging the amp into another outlet, i know in my house i can plug my amp into one outlet and get no hum from guitar, and other outlets i get hum from guitar..
#3
This may worth a look at: http://www.youtube.com/watch?v=qiYNaC7LQtg
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#4
Thanks! I switched outlets and the hum is now super reduced, gotta go around and find the perfect one.

Another problem has arisen though: When the guitar is upright (as if i'm playing it) it is fine, but if I tilt it so it lays flat on my lap, there is hum. I'm thinking this is a shielding issue? A train track goes right past my window so I'm wondering if it's likely that is the casue?

I havn't lined the cavity with foil or anything, there is just the foil on the back of the pickguard. Does lining the cavity make a big difference? and do I need to connect that foil to ground?

EDIT: ^ I'm from the UK, do they make that hum reducer for 50Hz?
Gibson SG
Laney Cub 10
Ibanez SD9M
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Last edited by XEasyTarget at Jul 4, 2013,
#5
I've shielded all the cavities on all but two of my guitars and did them all myself. I also used shielded cabling through the electronics. Shield foil is only 50% of the equation.

The fully shielded ones are silent. Not quiet or exhibiting a whisper of noise.....but dead silent, even with the gain and volume cranked.

The two which aren't have low level buzz all the time. The difference is very audible.

The shielding on my guitars works better than that Suhr backplate video which still has noise even when the backplate is 'on'

And yes, shield foil has to be grounded.
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Last edited by Phoenix V at Jul 4, 2013,
#6
Thanks for the info!

So to shield the main cavity, can I just line it with aluminium foil and ensure that the foil is grounded? Is that likely to show a reduction in hum? I believe the cabling is already shielded.
Gibson SG
Laney Cub 10
Ibanez SD9M
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#7
Not aluminium. Self adhesive copper foil thats conductive on both sides. You lay it down and overlap it, so the whole cavity is covered and its all conductive.

Not just the control cavity, but all the pickup cavities also.

And a strat has some shielded cabling, but theres a lot of spaghetti too.
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Last edited by Phoenix V at Jul 4, 2013,
#8
Cool, I'll get right on that then. Thanks for all the help everyone.
Gibson SG
Laney Cub 10
Ibanez SD9M
Ditto Looper
#9
Here's a kind of pictorial guide for sheilding a strat. He uses al foil in his slideshow. Adhesion conductive copper foil is much much better.

Strat Cavity Shielding
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#11
Thanks for that guide phoenix.

Yeah, it definitely is grounded. changing outlets completely got rid of the buzzing that stopped when I touched the strings. It's now more of a whirr that occurs when I point the pickups in certain directions. I think it must be electrical interference, as it is at its worst when I point them towards the train tracks (about 4ft from my window).

When i point the pickups away from the window, the guitar is near silent.
Gibson SG
Laney Cub 10
Ibanez SD9M
Ditto Looper