humbucker noise problem help please!!!

[Stengah]

Hello, I am having some issues with my Carvin pickups. I just built a custom guitar and upon installing the electronics, something wasn't right. The problem is I am getting an extra noise/hum from the pups that shouldn't be there. This noise goes away when I touch any of the metal components involved in the electronics, i.e. the volume pot, the switch, the screws holding the pickup in place, ect. This leads me to believe it is some sort of grounding problem, however I have double checked all of the grounds, switched out all of the pots, the switch, and the jack, and the problem will not go away. This leads me to believe to pickups are defective, but I'm wondering if anyone else has had the same problem/knows a solution or anything before I take it to a shop. Any input is greatly appreciated. Thanks.

The Carvin humbuckers are the M22 series, they've got 4 wires coming out [red(hot lead), black(hot ground), white, and green] plus a bare wire. It's a simple setup with one volume knob and one 3 way switch.

[Chuck H]

If you could post a schematic or diagram of your wiring (including all pickup wire colors, at least labled) it will help.

Chuck

[Stengah]

Here we go this should help. I whipped it up on Paint real quick. Let me know what you think. Thanks!

[David Schwab]

Your diagram kind of contradicts itself.

You say:

red=hot lead
black=hot ground (hot ground?)
bare= ground
white=to be taped off
nothing said about green wire

But that's not what you show. You diagram is right.

What you want is red = hot (+)
green and white connect together and get taped off.
Black and bare = ground (-)

http://www.carvinservice.com/crg/man...ng-rev2008.pdf

[Stengah]

Everything I showed in the diagram is what I did. Carvin didn't say anything about the green wire, but I assumed it needed to be soldered with the white and taped off based on other diagrams of similar pickups. The pickups appear to be working fine except for the extra noise.

[David Schwab]

Everything I showed in the diagram is what I did. Carvin didn't say anything about the green wire, but I assumed it needed to be soldered with the white and taped off based on other diagrams of similar pickups. The pickups appear to be working fine except for the extra noise.

In the PDF link they do show the green wire.

That kind of noise means you need better grounds in the guitar, or some shielding.

Are your strings grounded?

It could also be coming from the amp.

[Stengah]

There are no strings on the guitar, and it's not coming from the amp, I've tested the noise levels with other guitars, and the noise wouldn't go away if I touched the electronics if the amp was the problem. Also I have copper shielding tape lining the cavities. This is the 5th time I have installed electronics in a guitar, I don't see how the grounds could be any better, although I know that does seem to be the problem. I'll try to do something different. But also part of my question was, is it possible that the problem lies within the pickups themselves? It seems like I have tried everything.

[Chuck H]

There are no strings on the guitar, and it's not coming from the amp, I've tested the noise levels with other guitars, and the noise wouldn't go away if I touched the electronics if the amp was the problem.

Try touching the pickup hieght adjust screw head or the bridge. With no strings on the guitar hour hands don't automatically tough a ground. Unless you've already tried and that's what you meant by the above post. I couldn't be sure.

But also part of my question was, is it possible that the problem lies within the pickups themselves? It seems like I have tried everything.

Well... I don't think so. If the pickups are operating and sounding correct they are humbucking by nature. In order to not buck hum they wouldn't be working very well.

Also, is the noise present in all positions with both pickups??? I wouldn't think both pickups would be bad or incorrectly constructed.

Chuck

[David Schwab]

Also I have copper shielding tape lining the cavities.

Do you have the copper foil tape grounded?

It has to be grounded.

[Stengah]

Do you have the copper foil tape grounded?

It has to be grounded.

Yes the copper foil tape was grounded. And I just took it out completely and it didn't change anything.

[Chuck H]

Check the ground tab for the volume pot. Sometimes they can become disconnected from the resistance strip inside too. Especially with excessive heat from soldering blob grounds on the pot casing. Check all grounds for cold joints.

Chuck

[Stengah]

Chuck- I already switched out the volume pot with a different one and nothing changed. Also switched out the output jack and bypassed the switch. No luck.

[Chuck H]

Try bypassing everything with one pickup wired straight to the jack. Of course you need to have a ground lead, but otherwise everything should be bypassed. That should tell you something.

Chuck