Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Is shielding required on a passive P-bass?
- Thread starter N. Kentucky Bass
- Start date
The Thomastik-Infeld Jazz Bass flats arrived today. But the soldering iron is still in transit and won't arrive 'till Monday. Drat! Meanwhile, I removed the old strings and fired up better lighting to examine the pickup cavity. Does this look like copper shielding? I'm betting the pots cavity is also shielded, but with paint underneath the body coat as others have surmised.
No, that looks like a baseplate. If the cavity had copper shielding in it, you'd be able to see it going up the sides.
Got it back together and seems to be functioning well. Discovered there's a gray strip of tape underneath the pickguard over the pups cavity. Possibly more shielding?
That's shielding - and also, on many Fenders, that's what creates the ground side of the circuit since there aren't separate ground wires run between the pots.
I think that's the intent, but I never trust it. If it's me, I'm using copper tape and going over a bigger area. But that's just me.
I think the conductivity is the primary intent. The shielding seems to be an afterthought.
BTW I twisted the wires as much as possible but there wasn’t a large amount of slack. I’ll see if any noise manifests before proceeding to a copper tape project!
Thin aluminum foil like this gets damaged easily by toothed lockwashers, as you can easily see. Brass shimstock works much better, .008" is a good thickness.
DiabolusInMusic
Functionless Art is Merely Tolerated Vandalism
60hz noise (single coil noise) is addressed with humbuckers. Shielding will address RF interference (noise that stops when you touch metal). They are two different issues with separate resolutions.
Any time a P bass that I've been playing had a buzz or a hum that went away when I touched metal, it was a grounding problem - the ground wire came unsoldered from the pot. Any that didn't go away when I touched the strings was electrical noise from a noisy circuit in the wall, and persisted when I turned down the Volume on the bass itself and went away when I turned off the amp (of course). I've literally never ever had RF interference. I'm not an electronics engineer by any stretch of imagination, so I'm not saying this can *not* happen, I'm saying that since 1982, it has never happened once.
Last edited:
I think we are having a semantic argument here. "Grounding problem" or "shielding problem" mean different things to different people. The key fact is: noise is avoided when you have properly grounded shielding around your electronics.
Some people have basses that aren't shielded, and they are noisy. They need to add shielding and ground the shielding. Other people have basses with shielding, which is not properly grounded. They need to fix the ground.
Ultimately though, you keep noise out of your signal by shielding your signal-carrying wires, and then grounding the shield, so the noise shunts to ground instead of going down the cable to your amp.
Some people have basses that aren't shielded, and they are noisy. They need to add shielding and ground the shielding. Other people have basses with shielding, which is not properly grounded. They need to fix the ground.
Ultimately though, you keep noise out of your signal by shielding your signal-carrying wires, and then grounding the shield, so the noise shunts to ground instead of going down the cable to your amp.
Just received a reply from Fender as to whether my bass pot cavity is shielded.
Doug James (Fender)
Mar 4, 2021, 18:53 MST
Hey there,
Thank you for reaching out to us. All of the American Professional basses have shielded cavities and it is normal to see colored paint over the shielding paint, this does not affect the performance of the shielding. Let me know if you have any further questions.
Cheers,
Doug James
Gear Advisor
Fender Musical Instruments Corp.
17600 N. Perimeter Dr., Ste-100
Scottsdale, AZ 85255
(480) 845-5136
Doug James (Fender)
Mar 4, 2021, 18:53 MST
Hey there,
Thank you for reaching out to us. All of the American Professional basses have shielded cavities and it is normal to see colored paint over the shielding paint, this does not affect the performance of the shielding. Let me know if you have any further questions.
Cheers,
Doug James
Gear Advisor
Fender Musical Instruments Corp.
17600 N. Perimeter Dr., Ste-100
Scottsdale, AZ 85255
(480) 845-5136
