If you can upload a picture later, guys like line6man have always come through with knowledgeable and helpful information.
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Problem after re wireing
- Thread starter Eric Bates
- Start date
It sounds like there is a bad ground connection somewhere. It shouldn't be a problem of mixing hot and ground (you'd have no sound), or improper shielding (it would be a more faint hum and not constant). As others have said a picture would be helpful. Good luck!
That wire coming from the 2nd terminal of the jack looks like the problem. On the picture it looks like it is a thin as a hair.
I would have to agree with everybody else that you would be better of soldering the connections. Much more secure in the long run. Definetely worth the investment.
Great suggestion--- but not the cause of the hum.
First let me caveat this by letting you know I'm not a luthier nor am I a qualified electrician and there are others on TB more qualified than I. But I was an aircraft and auto mechanic and have some basic electrical training and experience.
Based on this thread so far, the assumption is that you are working with a 60Hz hum which is always related to a grounding issue.
When you removed the pups you lost the ground that goes to the pups even though you connected all the ground wires together. Of course, there are no pups to ground anymore but you may created a missing ground connection if the pup ground was designed to pass through to the jack.
Did you reinstall the pups and test for a hum? If the hum is still there with the pups back in then a problem developed elsewhere. If it's gone with the pups installed then you obviously lost a ground by removing the pups. In the latter case, you'll need to rethink your grounding schematic.
Knowing these answers will help with troubleshooting.
Does the bass hum only when you touch the strings or is it constant?
Do the strings make sound through the amp when plucked or not at all?
Were there any resistors or capacitors on the pups?
Is there a ground wire connecting the bridge and jack (or metal plate).
Is there a metal plate on the underside of your pickguard? Looks like it in the pic but can't be sure.
Based on this thread so far, the assumption is that you are working with a 60Hz hum which is always related to a grounding issue.
When you removed the pups you lost the ground that goes to the pups even though you connected all the ground wires together. Of course, there are no pups to ground anymore but you may created a missing ground connection if the pup ground was designed to pass through to the jack.
Did you reinstall the pups and test for a hum? If the hum is still there with the pups back in then a problem developed elsewhere. If it's gone with the pups installed then you obviously lost a ground by removing the pups. In the latter case, you'll need to rethink your grounding schematic.
Knowing these answers will help with troubleshooting.
Does the bass hum only when you touch the strings or is it constant?
Do the strings make sound through the amp when plucked or not at all?
Were there any resistors or capacitors on the pups?
Is there a ground wire connecting the bridge and jack (or metal plate).
Is there a metal plate on the underside of your pickguard? Looks like it in the pic but can't be sure.
First, I am going to solder the connections when I have time. Thank you John m. That was useful info. I didn't take the pups out. I removed the tone and volume pots. I'm not sure how a "missing ground connection" is created. There was a ground bus through out the intire guitar before and it still exists now. The sound stops when I touch any metal. There was a resistor between the pots. As I said earlier, the bridge is grounded... to the jack and the rest of the ground bus. Could the cheap pick ups just make a lot of noise without the resistance of the pots? And, I can plug my other bass into the same amp with the same cord, and no hum.
Hi there. I looked at the picture and the thing that caught my eye was the output jack. It seems to me that the tip where the hot wire from the pickup is soldered may get to close to the jack when it is inserted. Try bending it backwards a (fair) bit.
Joybass, thanks. That didn't stop it but it I'm wondering whether a tighter jack pushing on the cord would help. I'll try it.
I'm not seeing a ground connection to the jack. Usually there's a wire running from the back of one of the volume pot to the lug on the jack. All the grounds usually meet at the back of this pot. Did you remove a wire from the ground lug (ring) of the jack?
I soldered all the connections. The noise is still there. I'm starting to think it's just cheap, noisy pick ups. This is just a bass to take with me in the car so I may just live with it. And, I discovered the noise doesn't exist through my head phone amp.
As I see the problem based on your photo: I'm assuming the pickup ground wire was soldered to the back of the volume pot. Also connected there was the bridge ground. The pot ground was connected to the jack ground via that foil on the pickguard. So without the pot, there's nothing connecting those ground wires to the jack ground.
You need a wire to the other lug of the jack connected to your bridge and pickup grounds.
I couldn't see that little wire in the first pic. So... I am out of ideas. Other than the lack of shielding. I'd ask does the amount of hum change with the direction bass is facing? In any case, shielding should be required.
Thanks for all the help. The hum does not change when I change direction of the guitar. Right now, it sounds great through my head phone amp so I'm going to let it be for now.
Weird. I've never known even a cheap P bass pickup that was noisy when wired properly.
If all the metal components are connected with a ground wire then the hum is likely due to a lack of shielding. Passive single coil pickups are sensitive and vulnerable to picking up a hum and removing the pots and resistor can make it more vulnerable.
I don't see any shielding at all in the cavity or pickguard. I'm certain that if you properly shield it and ground the shielding with a dedicated wire you will eliminate the hum problem. I wouldn't be surprised if it sounded better too which I presume was the point of removing the pots in the first place.
I don't see any shielding at all in the cavity or pickguard. I'm certain that if you properly shield it and ground the shielding with a dedicated wire you will eliminate the hum problem. I wouldn't be surprised if it sounded better too which I presume was the point of removing the pots in the first place.
