Shielding Stratocaster

[Marco78]

Finally my Warmoth strat is arrived to my home!!  :blob7:

I have to shielding pickguard. On the back of pickups is already installed a alumium foil on pots side. Is it indispensable to cover the whole pickguard with alumium/copper foil? I'll use a graphite paint for the body...

 

[Updown]

Some will say yes.
Some will say don't bother.

Most pickguards come with it on anyway.

Also can depend on your pickups your using ...... any hint ? 

 

[Jumble Jumble]

The important thing to know about shielding is it does NOT reduce 60Hz hum. It reduces RF interference, for instance, from fluorescent lighting, transformers and CRT TVs.

You're aiming to make a grounded "box" around all the electronics. So do the back of the pickguard only in places where wires will travel, and then do the control and pickup cavities. And remember if the shielding isn't grounded, it's not doing anything (or in fact might be making things worse).

 

[Marco78]

I will install 3 single coil on it.

So I'd use shielding foil on central part of pickguard, because pickups wire travel in this part...

 

[Jumble Jumble]

Sounds sensible.

 

[Marco78]

Sounds sensible.

 

[Cagey]

The important thing to know about shielding is it does NOT reduce 60Hz hum. It reduces RF interference, for instance, from fluorescent lighting, transformers and CRT TVs.

You're aiming to make a grounded "box" around all the electronics. So do the back of the pickguard only in places where wires will travel, and then do the control and pickup cavities. And remember if the shielding isn't grounded, it's not doing anything (or in fact might be making things worse).

You might be thinking a little backwards there. Fluorescent lighting (ballast transformers), power transformers, TVs (power supply and flyback transformers), house wiring, etc. all produce 60hz emissions and little or no RFI. RFI stands for Radio Frequency Interference, which is much higher in the spectrum than even dogs and bats can hear. Shielding against it is pointless as it doesn't interfere with the audio frequency spectrum in the application we're concerned with here.

What you're trying to shield against in audio equipment like guitars, amps and accessories is usually known as EMI (ElectroMotive Interference), which is arguably the same thing, but at a much lower frequency which is often in the bandwidth of human hearing.

Either way, we're simply talking about oscillating magnetic fields. They differ only in bandwidth, wavelength and signal strength. Shielding against those emissions is also the same, varying only in how complete the shield needs to be.

In guitars with single coil pickups, there isn't much you can do. The pickup is necessarily exposed and behaves like a mile-long antenna, which means it's sensitive to very low frequencies. 60hz is puppy chow. You can shield the internal cavities all you want, but it won't have much effect. Shielded cable is your best bet, but it's like aspirin for a sprained ankle. Takes the edge off at best.

In guitars with "humbucking" pickups, you can still pickup up noise in the internal wiring, but it's easily subverted with shielded cable.

Conductive paint, copper tape and aluminum sheeting are largely an exercise in futility engaged in mainly as a feel-good move. It's all pretty ineffective.

But, none of it hurts anything, so there's no problem doing it.

 

[Dan025]

well cagey is right. you can try all you want to create a Faraday cage but it's as good as a screen door on a submarine.

on the other hand, bill lawrence seems to say that it's not futile. bill is the creator of the  l500xl pickup that dimebag darrel used. he was also behind some interesting guitars and factory pickups from fender gibson and others. what he says is that aluminum specifically has a weird property. it tends to block some emi even if it's not grounded, but it's partitcularly effective on emi from variac type dimer switched, it will not however get rid of 60 cycle transformer hum, for reasons stated by cagey only humbuckers will do that.. he doesn't get into the physics of it's emi reducing properties but i would suspect it has something to do with the eddies the feilds create in the material and the energy turning into heat. i could be wrong. but bill talks about leo fender having a strat with a .025" plate of aluminum under the pickguard for sheilding and the guitar having a sweet tone due to the eddy currents smoothing out some of the upper mids. a .003" piece of tape would have about zero effect on tone but it might help the noise from that variac dimmer switch used for the stage lighting where ever you may play..

http://www.billlawrence.com/Pages/Pickupology/External%20Interference.htm

i like his little tip about liquid downey on the pickguard. makes sense.

i would say that if you are gonna do sheilding go all the way with it. get noisless pickup, coaxial cable between the controls. coaxial pickup leads, aluminum under the pickguard and all. after all it would be frustrating to shield the guitar from dimmer noise but still pickup transformer hum because you wanted single coil pickups. or to use humbuckers but still be prone to all sorts of emi.

 

[jweemsns]

I just shielded the body of my strat. Do i still need to solder the bridge ground back to the bridgeplate  or am i able to use a ground post on the inside of my copper
shielding to re-attach that wire?

 

[Cagey]

That's sort of a confusing question, so I'm not sure how to answer it. But, consider this: bridges are all metal and as such are conductive. So, if any part of the bridge is grounded, then all of it is. The strings are also metal and necessarily tightly coupled to the bridge, so they're also grounded. On guitars with vibrato bridges, you can just ground the claw that holds the springs and you've grounded everything. On guitars with fixed bridges, usually the mounting studs get grounded which catches everything. The exception is if you've used "active" pickups such as EMG sells, in which case you don't need to ground any of it. The impedance is low enough that nothing is sensitive to EMI.