# Should i shield the control cavity when use active pickups?



## alvaro (Mar 5, 2008)

Hi, i am to replace my EMG81-7 by a blackout pickup...

so when opened the control cavity, i noticed that it was not insulated / shielded with copper sheet, conductive paint or anything... Shouldn't it be?

Thanks for your help.


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## bostjan (Mar 5, 2008)

I don't think it's as important, but I would definately shield everything.


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## OzzyC (Mar 5, 2008)

It wouldn't hurt any.


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## ibznorange (Mar 5, 2008)

yeah. why not? just because theres a preamp doesnt mean its immune to interference. Id shield any control cavity as long as it contains controls


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## alvaro (Mar 5, 2008)

My doubt comes because time ago i read on EMG Inc. that active pickups don't need to be grounded because they are already internally shielded or anything. But i don't know about the rest of electronics involved, i guess they are different concepts. I could not find any relevant info on EMG about this question. My luthier did not shielded my guitar's control cavity, but i read that others systematically do on every work... so my doubt is _when_ is necesary and when is irrelevant. I am about to buy a copper sheet shield kit and i am concerned it becomes a waste of money when using active electronics.

EDIT: ok ibznorange sorry, i posted before i read yours. It makes sense so i think ill finally do it.


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## ibznorange (Mar 5, 2008)

nope, wont be a waste. the pickups are shielded yeah, but the pots and switch and stuff arent

btw, they are internally shielded, but thats not why they dont need to be grounded. they also have an internal grounding loop. Just clarifying


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## giannifive (Mar 5, 2008)

If you shield the cavities be careful not to create any ground loops (loops of conducting material that are supposed to be grounded). Doing so could actually increase the hum!

See here (for strats, but the same principles apply): GuitarNuts.com - Shielding a Strat(tm)


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## alvaro (Mar 5, 2008)

Thank you for the link, giannifive, ill give it a look.


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## 7 Strings of Hate (Mar 5, 2008)

well, heres the question, did you have interferance problems with your emg? if not, why even worry about it. I'v had emg's for almost 10 years, never sheilded, and no problems, i wouldnt even worry about it


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## bostjan (Mar 5, 2008)

I had a problem with interference one time in nine years. I was playing right next to a cell tower and kept getting this awful hum. Everyone else was having issues as well. Shielding the pickups probably wouldn't have made much of a difference, though, even in that case, since the amp and the cable and even the old circuitry in the building were acting as inductors.


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## alvaro (Mar 6, 2008)

Well i play in front of the PC but i use TFT screens. I don't use real amps / cabinets anymore since years. So i guess it doesn't include me on the hum risk group. So maybe you are right.


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## Apophis (Mar 6, 2008)

Shield it, it won't be a problem , even it's not needed


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## Mattmc74 (Mar 6, 2008)

Do it!


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## ToneUniverse (Mar 6, 2008)

Use your time better, play the guitar.


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## Ruben69 (Dec 20, 2018)

Hi, the way actives work (and I've built several of my own too); I wouldn't shield anything.
It will dull the tone, pinch harmonics (harder) and generally sound less crisp. You won't get a noticable benefit doing it.

However, my Passives benefit from some shielding. Sheild paint is adequate to form a faraday cage around the control cavities. Copper over-mellows out your tone. Hope this helps.


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## Mike (Dec 20, 2018)

lol I know this is quite a necro but I was thinking of this myself the other day. Has there been any newer information related to this now that fishman's are a thing? Do they say anything about shielding?


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## KnightBrolaire (Dec 20, 2018)

Mike said:


> lol I know this is quite a necro but I was thinking of this myself the other day. Has there been any newer information related to this now that fishman's are a thing? Do they say anything about shielding?


when in doubt, shield the cavity. it never hurts to do, especially if you end up switching back to passives.


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## Mike (Dec 20, 2018)

If its an active equipped guitar with shielding paint, but no ground wire from the bridge, is the easiest solution to just drill a screw into the control cavity to act as a ground?


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