Hey everyone. So, I've been dealing with noise issues on my Steve Harris P-Bass for about two years now, and I've tried everything to fix it—from replacing the electronics to swapping the pickup. After gathering some info recently (since I haven't given up yet), I tested the grounding on the bass's metal parts and noticed that the aluminum pickguard is the only component lacking ground continuity (the reading fluctuates and never drops to zero); the knobs, output jack, strings, and tuners all show continuity when measured against the bridge ground. It seems the ungrounded pickguard is preventing the "Faraday cage" effect that should shield the circuit from external noise. That said, I think I've identified the cause, but I'd like to hear from people who know more about electronics than I do. I'm planning to take it to my trusted luthier in a few days to discuss options for grounding that blasted pickguard.
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I think i found the solution
- Thread starter Asllan Pizzatto
- Start date
If the pots are properly grounded and they're tightened down to the pick guard then the pick guard SHOULD be grounded.
Should is the operative word here. The star washers on potentiometers don't always make a really good electrical connection.
A metal plate that isn't well grounded becomes the opposite of a Faraday cage; It becomes an antenna, so your theory that the pick guard is causing noise instead of preventing it is a sound one.
Solving the issue might be as simple as lightly sanding the surface where it comes into contact with the pots or as complicated as soldering a ground lead to the pick guard but, either way, it shouldn't be too difficult to get the guard grounded and then you'll see whether that was the cause or not.
Should is the operative word here. The star washers on potentiometers don't always make a really good electrical connection.
A metal plate that isn't well grounded becomes the opposite of a Faraday cage; It becomes an antenna, so your theory that the pick guard is causing noise instead of preventing it is a sound one.
Solving the issue might be as simple as lightly sanding the surface where it comes into contact with the pots or as complicated as soldering a ground lead to the pick guard but, either way, it shouldn't be too difficult to get the guard grounded and then you'll see whether that was the cause or not.
Então, quando troquei a parte eletrônica, instalei potenciômetros CTS de eixo sólido. Os botões originais da Fender não serviam mais, então comprei uns idênticos na All Parts — que são de excelente qualidade —, mas notei que estavam ligeiramente soltos, por uma fração de milímetro. Talvez esse seja parte do problema. Lixar a parte interna provavelmente é uma ótima opção para garantir um contato sólido entre os metais.
Get some copper shielding tape and run a strip from the bottom of the pickguard to literally anything else there that's reading "0" and that should solve the problem. If it doesn't, then maybe involve the Luthier, but this should be a 5-10 min fix that costs you very little to do.
I had a noise issue with a Squier p5 after shielding the cavity and pick guard. I also installed a Nordstrand pick up. I verified continuity between all of the copper shielding. I determined that the metal part of the pickup was not tied to the ground of the system, so I temporarily installed one (alligator clips). The noise went away, so I soldered a permanent jumper between the pickup case and the common ground point.
What's the ohm reading between one edge of the pickguard and the other? It looks like it's chromed which should be conductive but some coatings aren't.
The output jack is anchored to the pick guard, so I am really skeptical that the pick guard is ungrounded. Using an ohm meter, check between the bridge and the nut on th output jack then check between the bridge and the head of one of the pick guard screws. Let us know what you find.
Ambos com uma média de 0,05 ohms (medida usando a configuração de referência de 20k).
Oops, sorry. Both with an average of 0.05 ohms (measured using the 20k reference setting).
0,05 Ohms é um valor realmente muito baixo. Ainda assim, pode valer a pena lixar a parte de trás da proteção para garantir uma boa conexão, mas o problema pode estar em outro lugar.
(0.05 Ohms is really pretty low. It still might be worth sanding the back of the guard to ensure a good connection, but your problem might lie elsewhere.)
The thing is, there really isn't anywhere else the problem could be
unless the issue lies in the wood itself. I've already replaced the entire wiring and the pickups, shielded the cavities, and—believe it or not—it stayed exactly the same. The only thing I haven't touched is the aluminum pickguard. I'm going to discuss the possibilities with my luthier, but lining the back of the pickguard with conductive tape might just solve it. It is the only metal part that does not exhibit conductivity. On the other bass, everything works normally with the same equipment (cables, pedal, interface).
