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Topic: Shielding to reduce hum |
Jim Rossen
From:
Iowa, USA
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Posted 4 Dec 2016 7:15 am |
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Is cavity shielding with copper foil more effective than multiple coats of black conductive paint?
Is there benefit to using shielded cable for ground wires?
Anyone have experience with hum reducing pedals?
Thanks
Jim |
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Jon Light
From:
Saugerties, NY
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Posted 4 Dec 2016 7:58 am
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re: pedals, search the Forum for EH Hum Debugger. I've written extensively on it.
Summary. It works REALLY REALLY well. But not without some cost in tone. Only the user can decide if the problem is bad enough to justify this trade off. The fix (specifically for 60 cycle hum,) is by far the most effective I've found. If I can avoid using it, I don't use it. If I have a room where I feel I need it, I use it without hesitation.
There's one for sale here right now. |
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George Piburn
From:
The Land of Enchantment New Mexico
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Posted 4 Dec 2016 8:20 am Hum dingers
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Is cavity shielding with copper foil more effective than multiple coats of black conductive paint?
A Combination of both with a soldered connection from the copper is best, I think Toms Recommendation of the Nickel paint is the better conductor - Also if you are using a plastic or metal pickguard type area for the pickup be sure to shield that and connect to the ground plane creating a complete shield box around the lower part of the pickup - same with any control cover plate.
We even copper shield the bobbin of our single coils pickups.
Is there benefit to using shielded cable for ground wires?
No-- a Bare Wire is plenty good - although Robert Allen's recommendation of a single grounding point is well observed do not forget to include the pot cases - their ground lugs - the output jack ground - the link to the bridge-strings- cavity shields - cover shields.
For Maximum protection add a water pipe ground with # 6 Welding cable.
_________________
GeorgeBoards S8 Non Pedal Steel Guitar Instruments
Maker of One of a Kind Works of Art that play music too.
Instructional DVDs
YouTube Channel |
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Jack Hanson
From:
San Luis Valley, USA
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Posted 4 Dec 2016 11:53 am Re: Hum dingers
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| George Piburn wrote: |
| A Combination of both with a soldered connection from the copper is best |
Wouldn't the compression of the star washers from the pots into the copper foil accomplish the same thing?
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Randy Schneider
From:
SW New Mexico, USA
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Posted 4 Dec 2016 12:51 pm
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| Quote: |
| Wouldn't the compression of the star washers from the pots into the copper foil accomplish the same thing? |
On one of my electric guitars, the tone controls weren't working. Then I read online about the makers sometimes relying on the pots' nut/washer connections to the pickguard shielding to provide ground. Tightened the nuts on the pots -- tone controls started working again.
Next time it needs strings, it's getting soldered connections. |
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George Piburn
From:
The Land of Enchantment New Mexico
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Posted 4 Dec 2016 1:54 pm Hum
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Jack - Adding a soldered wire to the ground plane will always be better than contact only for endurance.
In the instance of your photo,
Copper and Aluminum foils filter different Radio aka RFI frequency's and are good in general
+ one little quick solder will reinforce it permanently.
Your's could use a tab of copper up onto the lip where it has the screw holes, to connect to more shield on the cover.
We place a bit of fabric E-tape onto the shield under the potentiometer lugs to help prevent shorts as well.
Hum aka Inducted interference is shielded by using the Carbon or Nickel paints.
Hope this helps folks to De Hum some.
_________________
GeorgeBoards S8 Non Pedal Steel Guitar Instruments
Maker of One of a Kind Works of Art that play music too.
Instructional DVDs
YouTube Channel |
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Jack Hanson
From:
San Luis Valley, USA
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Posted 4 Dec 2016 2:39 pm
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| Thanks, George. Since the instrument in the photo is quiet as a church mouse, even with a P-90, I'm hesitant to fix what ain't broke. I will definitely follow your advice and do a better job of shielding on my next rebuild. |
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Tom Pettingill
From:
California, USA (deceased)
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Posted 5 Dec 2016 5:04 pm Re: Shielding to reduce hum
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| Jim Rossen wrote: |
| Is cavity shielding with copper foil more effective than multiple coats of black conductive paint? ... |
Both have their pros and cons, but if properly done, both can work very well.
My personal preference is MG Chemicals nickel conductive SuperSheild. Its not too pricy, works great, and I like that its in a spray can. They do have a carbon based one, Total Ground, in a spray can too, but like the brush on stuff, you will need more coats.
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Some misc pics of my hand crafted steels
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