Shield or not?

[Down Time]

I've been shielding single coil guitar cavities and pickguards, copper tape on the pickguard and three coats of conductive paint in the cavities. All connected to ground. I've noticed a little less high end sparkle. Is this something anyone else has noticed? Or is this all in my mind?

[guitician]

Adding shielding will add what is called "Stray Capacitance" and it will change the high frequencies due to "shunting" them to ground.
Capacitance - Wikipedia, the free encyclopedia

[Down Time]

Adding shielding will add what is called "Stray Capacitance" and it will change the high frequencies due to "shunting" them to ground.
Capacitance - Wikipedia, the free encyclopedia

Thanks, I knew I was hearing a change.

[Mike Sulzer]

I've been shielding single coil guitar cavities and pickguards, copper tape on the pickguard and three coats of conductive paint in the cavities. All connected to ground. I've noticed a little less high end sparkle. Is this something anyone else has noticed? Or is this all in my mind?

All in your mind. You are not adding enough to matter. And if you want to make up for it, shorten your cable by a couple of inches or so.

[David Schwab]

Thanks, I knew I was hearing a change.

Unless you are wrapping copper foil around the pickups, you aren't hearing any difference. If you are wrapping the foil around the pickups, leave a gap so it doesn't form a loop.

Did you also make other changes to the wiring besides the foil?

You can prove it for yourself by isolating the foil in the control cavity from the pots and then wire up one wire from the foil, and put a switch to ground. Now switch the switch on and off to ground the foil. Do you hear a change? You wont.

The foil is too far from any of the wires in the guitar to act as a capacitor IMO. And even if it did, it would be negligible.

Like Mike said, your patch cord has far more capacitance.

[guitician]

I can't tell you what you are hearing or not. I was just showing you a theory behind the loss of "highs". I know that "Sparkle" can be lessened by many things like resistance, inductance, reactance etc. I know that some cables that I have used can really dull that "Sparkle". Those old fenders that used cloth wires sure do have sparkle to them.

[automan]

Those old fenders that used cloth wires sure do have sparkle to them.

That's because they are usually plugged into an equally old fender amp

[Down Time]

Thanks David, that's a great test hook a mini switch taking the shielding in and out of the ground. Also thanks guitician for the theory involved.

[David Schwab]

Thanks David, that's a great test hook a mini switch taking the shielding in and out of the ground.

I make fully shielded pickups, and I have disconnected the shield connection, and the only thing that changes is you hear some buzzing.

[Possum]

...

If you are shielding the cavities and the pickguard and all that stuff yes you'll hear a difference. Visit Guitarnuts.com they have extensive material on shielding strats etc. You also don't want to use shielded wiring harness in a strat, that stuff really sucks the highs and sparkle out of pickups.

[Down Time]

If you are shielding the cavities and the pickguard and all that stuff yes you'll hear a difference. Visit Guitarnuts.com they have extensive material on shielding strats etc. You also don't want to use shielded wiring harness in a strat, that stuff really sucks the highs and sparkle out of pickups.

I did not try the switch test yet. I did not foil wrap the pickups or use shielded hook up wire. What got me wondering on this shielding thing is one of my Strats I've played for many years, I just shielded the cavity and pickguard. I know what this guitar sounds like. I think it lost some high end sparkle.

[Possum]

...

I've read that shielding the pickguard will kill some treble, I don't know much about shielding the cavities, but basically all the shielding provides a place for eddy currents to occur, they oppose treble and knock it down. Fender did use pickguard shielding in the early 60's I think, not sure about before that, would have to check my strat book. guitarnuts.com is a good place to read about this stuff....

[Joe Gwinn]

I've read that shielding the pickguard will kill some treble, I don't know much about shielding the cavities, but basically all the shielding provides a place for eddy currents to occur, they oppose treble and knock it down. Fender did use pickguard shielding in the early 60's I think, not sure about before that, would have to check my strat book. guitarnuts.com is a good place to read about this stuff....

A pickup sitting in a hole in a sheet of aluminum foil may well experience eddy-current loading from the sheet.

The quick fix is to make a single radial cut from the pickup hole outward to the edge of the pickguard, opening the closed loop around the pickup.

To keep the cut edges from touching and reconnecting, it may be necessary to make two parallel cuts, and peel up and remove the foil between the cuts.

[David Schwab]

A pickup sitting in a hole in a sheet of aluminum foil may well experience eddy-current loading from the sheet.

The quick fix is to make a single radial cut from the pickup hole outward to the edge of the pickguard, opening the closed loop around the pickup.

To keep the cut edges from touching and reconnecting, it may be necessary to make two parallel cuts, and peel up and remove the foil between the cuts.

I was going to post that, but you beat me to it.

[Possum]

....

I think you could do something similar wit cavity shielding, split it into halves with maybe just one connection on one side. I like hum.....