Picture of Tidy up your bass or guitar to avoid RF interference
I bought a MusicMan Stingray bass clone. It's a nice-looking bass (see picture) with a pretty decent sound despite its low price. It has an active circuit with an humbucking pickup that effectively blocks the AC buzz even at high volumes. But it also had an irritating interference from some FM or AM radio station. Not advertised on the package! The RF was not very noticeable at low volumes, but it came out quite clearly otherwise.

So if you have a similar problem with your "generic" bass or guitar, you may find this instructable useful.

Of course I had to make sure that the problem was not with other components of my setup, so I replaced cables, tested the bass with my son's guitar amp (at low volumes -- I didn't want to buy him a new one) and even used a battery-powered headphone amp, but the radio station was still there. I eventually plugged my son's guitars to the bass amp -- lots of hum, but no RF interference. So please test your setup and make sure the problem is with your instrument before trying anything, otherwise you will only frustrate yourself!

Now I'll show you the method used to solve the problem, which was surprisingly effective considering the simple and inexpensive materials I used and that it took me slightly over 3 hours. So let's get started!

Important: be sure you are handy with tools and have good soldering skills. Don't blame me if anything goes wrong!
mattellis2 years ago
I get copper shielding from a local stained glass store. They sell self-adhesive copper sheet, about 10" square I think for about $5. The sheet is easy to cut to shape, and is great for lining electronics cavities on guitars, and for shielding the underside of the pickguard. You can make a piece to fit the bottom of the cavity by laying the sheet over the cavity and burnishing the edge of the cavity (through the sheet) with your finger. This makes an exact outline of the cavity shape on the copper sheet. Cut this out, with some tabs to connect to the cavity wall shielding. The wall shielding is made by cutting a strip as wide as the depth of the cavity, and sticking it to the sides of the cavity. The side shielding can be soldered to the cavity bottom shielding at a couple of points for electrical continuity.

The pickguard shield can be made the same way as the cavity bottom pattern, by burnishing the copper sheet against the underside of the pickguard (with controls removed). It can then be cut out with appropriate holes for controls, etc. Just make sure you don't make a mirror image pattern that only fits the top of the pickguard (like I did the first time).
sstein12 years ago
nice work. I did this with my Les Paul (epiphone) custom just to improve the sound quality after swapping out the pickups. I would say that any one who has the skills to do what you showed and has a generic or clone model guitar should do this even if their not getting RF interference. Great share.
LucDaRocka12 years ago
Nice, I want a real stingray someday!
MrBillG592 years ago
Where did you get the copper tape?
mikeasaurus2 years ago
Good info, thanks for sharing. This would be a good candidate for the Musical Instruments Contest we are currently running.