Howdy, I'm not sure it this is the right place for this, but I threw a set of basslines spb-3 pickups I got used in my old squire affinity precision. I used brand new fender 250k pots(only used fender because that's what the local shop carries) with just a simple volume/tone setup. I followed the diagram on the website and I guess I screwed up because now I've got this terrible buzzing whenever I touch anything metal and the volume pot works backwards(up is down/down is up). I'm not sure what I did wrong, but I'd really appreciate any help, thanks in advance.
Problem with p bass quarter pounders
- Thread starter Riggs
- Start date
F
Funkfingers
Guest
Re: Problem with p bass quarter pounders
Welcome to the forum.
The buzz is caused by poor or incomplete grounding.
Take a look into the control cavity. Emerging from a hole on one side of the cavity, not far from the output jack socket, there should be a wire from the bridge assembly. This needs to be soldered to either the chassis of one of the control pots or to the ground lug of the instrument's output jack.
If this wire already is soldered to ground, you might have the connections reversed on the jack socket. You may be using the wrong lugs of a TRS ("stereo") socket.
At this point, photographs of your wiring become necessary to diagnose any other contributing factors.
Welcome to the forum.
The buzz is caused by poor or incomplete grounding.
Take a look into the control cavity. Emerging from a hole on one side of the cavity, not far from the output jack socket, there should be a wire from the bridge assembly. This needs to be soldered to either the chassis of one of the control pots or to the ground lug of the instrument's output jack.
If this wire already is soldered to ground, you might have the connections reversed on the jack socket. You may be using the wrong lugs of a TRS ("stereo") socket.
At this point, photographs of your wiring become necessary to diagnose any other contributing factors.
ItsaBass
New member
Re: Problem with p bass quarter pounders
The soldering looks to have problems all around, though it is not the worst that it could be. It looks like you didn't prepare any of the joint surfaces (rough or tin them), didn't cover ("wet") your connections with enough solder, made some cold joints, and didn't ensure proper connections prior to applying the solder (the solder itself should not form anything but a very thin – practically microscopic – connection between two components; the components should be connected anyhow, and the solder just holds the connection in place). I can't tell, but you might have a joint that is made entirely of solder between the volume pot's ground lug and casing. if so, you should remove the solder, then smash the lug into the casing more, so the connection is there even without the solder. (You could also forget bending the lug in, and just use a wire to ground the pot.) Your bridge ground wire also might not be properly contacting the bridge. But repair the soldering first and see what happens, so you don't have remove your bridge unnecessarily.
I would go to the library and look for a book that explains proper soldering techniques and problems, so you can have it open in front of your while you are soldering.
The soldering looks to have problems all around, though it is not the worst that it could be. It looks like you didn't prepare any of the joint surfaces (rough or tin them), didn't cover ("wet") your connections with enough solder, made some cold joints, and didn't ensure proper connections prior to applying the solder (the solder itself should not form anything but a very thin – practically microscopic – connection between two components; the components should be connected anyhow, and the solder just holds the connection in place). I can't tell, but you might have a joint that is made entirely of solder between the volume pot's ground lug and casing. if so, you should remove the solder, then smash the lug into the casing more, so the connection is there even without the solder. (You could also forget bending the lug in, and just use a wire to ground the pot.) Your bridge ground wire also might not be properly contacting the bridge. But repair the soldering first and see what happens, so you don't have remove your bridge unnecessarily.
I would go to the library and look for a book that explains proper soldering techniques and problems, so you can have it open in front of your while you are soldering.
F
Funkfingers
Guest
Re: Problem with p bass quarter pounders
The photograph does not show a wide enough area to follow the cables.
The fact that the capacitor leg inadvertently shorts against the chassis of the tone pot is immaterial since no signal appears to connected to the pot's input terminal.
The photograph does not show a wide enough area to follow the cables.
The fact that the capacitor leg inadvertently shorts against the chassis of the tone pot is immaterial since no signal appears to connected to the pot's input terminal.
Re: Problem with p bass quarter pounders
thanks for the input everybody, I hope these pics help a little bit. I knew I didn't do too well on the joints, though the lug on the volume pot was touching the back already. The ground wire isn't soldered under the bridge, it was that way from the factory. Never had any problems out of it before so I figured wth, let it be. As far as the capacitor touching the back of the pot I bent the rungs where they weren't touching and there wasn't any change. I got a feeling it's the joints themselves seeing as the jack is right according to the diagram. Then again what do I know, I'm a welder, not an electrician.
thanks for the input everybody, I hope these pics help a little bit. I knew I didn't do too well on the joints, though the lug on the volume pot was touching the back already. The ground wire isn't soldered under the bridge, it was that way from the factory. Never had any problems out of it before so I figured wth, let it be. As far as the capacitor touching the back of the pot I bent the rungs where they weren't touching and there wasn't any change. I got a feeling it's the joints themselves seeing as the jack is right according to the diagram. Then again what do I know, I'm a welder, not an electrician.
F
Funkfingers
Guest
Re: Problem with p bass quarter pounders
The missing ingredient in your circuit is a ground connection between the chassis of the tone pot and that of the volume pot. (Some P Bass examples form this bridge through the screening material on the underside of the pickguard. Your example lacks this.)
The missing ingredient in your circuit is a ground connection between the chassis of the tone pot and that of the volume pot. (Some P Bass examples form this bridge through the screening material on the underside of the pickguard. Your example lacks this.)
F
Funkfingers
Guest
Re: Problem with p bass quarter pounders
Solder an insulated wire to the metal chassis of the volume pot. Solder the other end of the wire to the chassis of the tone pot.
The grounding circuit will be completed by the existing wire that runs from the chassis of the tone pot to the output socket.
EDIT - The "missing" wire compensates for your pickguard not having metal foil insulation like a Fender Am Std or the solid metal sheet of some vintage pieces. The metal forms part of the ground path but never appears in the schematic diagrams.
Solder an insulated wire to the metal chassis of the volume pot. Solder the other end of the wire to the chassis of the tone pot.
The grounding circuit will be completed by the existing wire that runs from the chassis of the tone pot to the output socket.
EDIT - The "missing" wire compensates for your pickguard not having metal foil insulation like a Fender Am Std or the solid metal sheet of some vintage pieces. The metal forms part of the ground path but never appears in the schematic diagrams.
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