hum/buzz when touching humbucker cover (out of phase only)

[iamtak]

Hi, I've got a problem that's got me stumped.

I recently rewired my guitar, an epiphone dot. It now has three pickups - a pair of phat cats and a Custom Custom in the middle.

Here's a basic run down:
The pair of phatcats run to a three way switch.
The Custom Custom runs to a push/pull pot wired to flip it out of phase and then runs to a dedicated volume pot. I followed this diagram for the push/pull: http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=phase_switching_for_hb
After this, everything meets up at another 3way switch (phat cats/HB+PC/custom custom) and a master vol/master tone pair.

Everything is a-okay except for one thing - when the custom custom is flipped out of phase, when i come in contact with the cover, i get a quiet buzzing/humming sound. It's so quiet that you might not notice it if you were playing very busy stuff - but its noticeable when playing delicate music that has lots of space between notes.

What's really confusing is that this buzzing occurs when the HB runs solo, but only when the push/pull is engaged up (out of phase). When the push pull is down, and the HB is solo, there is no buzzing when touching the pickup cover. To me that indicates it is something to do with the wiring of the push pull pot. To reiterate, this problem only happens with the HB is selected out of phase, regardless if there are other pickups selected or not.

I thought there might have been a grounding issue with the cover (covers are grounded, right?) so I taped a section of wire from the pickup cover to the tailpiece of the guitar (externally - no way I'm pulling everything back through the f-holes if it can be avoided!). When the push pull pot is down (in phase) there's no buzz, everything works a-okay as before. However, when the push pull is up and the cover is grounded to the tailpiece, there's no signal at all. Silence.

So does this mean that I've somehow made the cover hot when it's flipped out of phase? I really don't know what's going on. Any advice would be appreciated. I really like the funky out of phase sounds and would like to be able to use them without fear of buzzing.

Thanks,
Tak

 

[jeremy]

Re: hum/buzz when touching humbucker cover (out of phase only)

welcome to the forum!

sounds like the bare wire is either wired to the phase switch or touching something it shouldnt.

the bare wire is the cover ground and should be separate from the green or black wire that go to the phase switch

 

[Funkfingers]

Re: hum/buzz when touching humbucker cover (out of phase only)

+1

When you engage the phase reversal switch, you have inadvertantly taken the pickup's metal cover out of the screening circuit and turned it into a RF interference antenna.

 

[iamtak]

Re: hum/buzz when touching humbucker cover (out of phase only)

ah hah! Thanks for the speedy replies.
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=phase_switching_for_hb So where it says "green and bare," it should really say "green"?

I felt kinda wrong for soldering the bare to anything but the back of a pot!

 

[jeremy]

Re: hum/buzz when touching humbucker cover (out of phase only)

yup, bare wire always (like really always) goes to ground

 

[iamtak]

Re: hum/buzz when touching humbucker cover (out of phase only)

yup, bare wire always (like really always) goes to ground

Got everything all fixed up last night. This diagram isn't quite right: http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=phase_switching_for_hb

Where it says "green and bare" it should just say "green". And as Jeremy says, "bare wire always (like really always) goes to ground."

Just posting this back up in hopes that anyone who has a similar problem in the future might stumble across this thread and find their solution.

Thanks for the help!

 

[GuitarDoc]

Re: hum/buzz when touching humbucker cover (out of phase only)

Sounds like you may have connected the bare wire to the green wire and now it's included in the circuit that is switched to get OOP. Or like was said, it may be inadvertantly touching a wire or contact that it shouldn't.

 

[Harold of Tewkesbury]

Re: hum/buzz when touching humbucker cover (out of phase only)

I have the problem 'Funky Fingers' describes. cover buzzes when out of phase position is selected on 5 way tele switch, guitar has neck humbucker. all other position are good. is there a quick fix for this problem. The telecaster has single coil bridge and braided humbucker(hot wire and braided earth) on neck with 5 way switch : position 4 is out of phase and there is earth buzz on humbucker cover, which stops when touched. thanks H.P

 

[GuitarDoc]

Re: hum/buzz when touching humbucker cover (out of phase only)

Just remember that with Teles, the pickup covers are grounded with the start coil wire under the cover. If you are doing switching, like phase, you ONLY want to be using the coil wires...the case ground wire needs to be separated from the coil wires and you have to add a wire soldered to the case and go to a ground. The humbucker is the same thing. The cover (through the baseplate) has to be grounded separately from the 4 coil wires.

 

[Harold of Tewkesbury]

Re: hum/buzz when touching humbucker cover (out of phase only)

The humbucker neck pickup has a braided outer wire and an inner covered hot, it's not the type with the four wires. Does your much needed advice still apply? thanks H.P

 

[GuitarDoc]

Re: hum/buzz when touching humbucker cover (out of phase only)

Yes. You need to remove the cover, separate the braided wire from the coil start wire (usually green). Make sure the braided wire remains soldered to the baseplate, that wire will be grounded (to the back of a pot). Splice a wire onto the coil start wire which will be used (with the black hot wire) for phase control. You will see two other coil wires spliced together, these are what is normally the red and white wires.

 

[Harold of Tewkesbury]

Re: hum/buzz when touching humbucker cover (out of phase only)

thanks GuitarDoc. I think I'll take it to a pro. All the best H.P

 

[GuitarDoc]

Re: hum/buzz when touching humbucker cover (out of phase only)

Good luck