Post by ChrisK on May 11, 2008 13:33:57 GMT -5
Its a stage and there a bunch of huge racks with lights all over them that have 10 different presets of dimness. They just shine straight down onto my pickups.
Oh, you didn't indicate that you were having photonic interference.
Just take yer guitar oot shopping and get it a pair of "cheap sunglasses".
The cheapest thing to try is to ensure that there is good continuity within your shielding. When I shield, I use the widest copper piece that I can find, preferable as wide as the width of the cavity. I cut it to just fit on the bottom, leaving tabs around the edges every inch or two. For the side walls, I use copper tape as wide as the cavity height. 2" copper tape works here. If I can't leave tabs everywhere on the bottom piece, I cut them on the side wall tape (2" is usually wider than most cavities are deep). After the tape is in place, I solder these tabs to the other piece (I first remove the adhesive from the tab back). Again, this is about every inch (preferable) or two.
The glue on the tape is to hold the tape in place on the cavity. It is not the best conductor of electricity.
What you're trying to do with the shield is to create a Faraday cage or "wrapping" around the circuitry that is connected to the system ground point as close to the signal input point on the amp as possible. Unfortunately, this is usually the cable shield/ground at the exit point of the guitar. In essence, this Faraday shield is an antenna that "receives" interference and shunts it to ground around, AND NOT THRU the string signal chain.
For best signal integrity, we don't want any currents flowing thru the shield. While the (slightly) better point for this common connection is the output jack, realistically we use the back of the volume pot as the star ground point. The most preferable method would be to have two electrically balanced signal wires surrounded by a shield that only is used to convey interference around said signal path. I think that we have a name for this somewhere........ I also find it most interesting that is is much more prevalent in basses rather than guitars..................
Guitars weren't designed the way that they are because it was the best way (all vintage virtue "exudication" aside), but because it was the CHEAPEST AVAILABLE way.
After all, the width of railroad track is based only on the legacy inheritance of the width of the asses of two horses. (Horse chariot/horse wagon/road ruts/common components/railways.)
ALL internal ground reference points should merge here (even the ones that may be capacitor isolated have one lead of the cap attached here). This includes the following:
1. The tone pot/cap sub-circuit(s) including backshells
2. The cavity shield wire(s)
3. The bridge/string ground
4. Any pickup shields/bare wires
5. The bottom "0" pot terminal
6. The cable shield
&. Any others