1) Does anyone find a change in tone from single coils after installing shielding? (Other than the obvious lack of hum.)
2) Does thickness of shielding matter? I have found a "gilding" kit at a craft store -- thin, thin copper sheets with a brush-on adhesive -- for around eight bucks that looks easy to use. (The man at GuitarNuts mentions the stuff on his epic web page on shielding but doesn't say how well it works.)
"You can't write a chord ugly enough to say what you want to say sometimes, so you have to rely on a giraffe filled with whipped cream." - Frank Zappa
I don't notice a difference in tone from shielding. I usually use aluminum duct tape for myself.
For others, I may use the same, or often thicker copper which is harder to use, and is actually thin metal.
I don't often shield cavities for myself, but it is a good idea, and again I do it for other people, a lot of work. :roll:
That craft kit will work, and so does carbon paint. I assume that the thicker or heavier the shielding is, the better.
Like a bird on the wire,
like a drunk in a midnight choir
I have tried in my way to be free.
yes -- it's possible to make single coils sound duller if the shielding very close to the coils. reason is simple: parasitic capacitance between the coil windings and the shield bleeds away higher freqs. if you are having this problem, shield the cavity, not the pup itself, as a little distance between the coil and shield should address this.
at these low (audio and AM radio range) freqs, the thickness of the shield is not really important, but the conductivity is. a paint-on shield doesn't usually have quite as good (high) conductivity (equivalent to low resistivity) as foils. but foils can suffer from poor connections at joins and overlaps. simple advice: if a painted shield seems to improve the hum and RF rejection a little, try another coat or two to see if more improvement is possible. if you are using copper tape or sheets, leave few or no gaps, and try adding some periodic (with distance) solder "tacking" connections where the tape joins or overlaps. if using aluminum tape, you may want to switch, as aluminum oxide is an insulator (unlike copper oxide), so shield integrity may be iffy -- esp over time. aluminum tape is a usually cheaper than copper tape, which is why makers use it. but is has to be applied correctly for good performance initially and over time.
thin, copper gilding sheets may work well, but you may have a problem with connecting the sections, as most adhesives are not conductive. copper shielding tape is supposed to have conductive adhesive -- though I've always wondered how conductive. the gilding may also be clear coated to maintain lustre. you should remove that coating at the overlapping seams. if you are going to use these gilding sheets, I recommend wide overlap areas and/or solder "tacking" at seams as mentioned above.
other and related: don't use ferrous (iron, steel) sheets to shield or as a pick guard, thinking it will be an ideal shield. it will shield, but also muck up the pups' magnetic fields. floating (unconnected shields) produce unpredictable results unless they are perfect enclosures, with no gaps. of course, that isn't really practical, so always connect the various parts of the shield together as intimately as possible and to the guitar's common grounding point.
-=tension & release=-
Thank you both! I picked up the gilding kit & will run some tests for conductivity and solder-ability on scrap wood.
I've used conductive paint (designed for PCB repair) and aluminum foil in the past, with reasonably good results. The paint is hard to find, and tinfoil is hard to use. I'm hoping the gilding foil will be easier to maneuver in cavity corners.
"You can't write a chord ugly enough to say what you want to say sometimes, so you have to rely on a giraffe filled with whipped cream." - Frank Zappa
Just a brief report on gilding foil, if anyone is interested: The stuff is extremely delicate. If you have the hands of a surgeon and a perfectly smooth surface, you might be able to make it work, with practice, as shielding material. Otherwise, expect lots of holes in your shield.
"You can't write a chord ugly enough to say what you want to say sometimes, so you have to rely on a giraffe filled with whipped cream." - Frank Zappa
small holes won't matter. many high performance electromagnetically "screened rooms" are constructed of copper screening.
-=tension & release=-
small holes won't matter. many high performance electromagnetically "screened rooms" are constructed of copper screening.
You're right, of course. Maybe I'll try this stuff on one of my buzzy single-coil pieces & report back on the results.
"You can't write a chord ugly enough to say what you want to say sometimes, so you have to rely on a giraffe filled with whipped cream." - Frank Zappa
