Wiring problem? Help please guys

[Diocletian]

I never thought too much of this before but now I realise it's probably a fairly big problem.

My Epi SG310, with Custom 5/Jazz in it, has an odd problem. When I switch to the neck pickup, and turn it down ALL THE WAY, I can still hear the bridge pickup just quietly/clean. Same thing when I select the bridge and turn that right down - I can hear the neck pup quietly.
I've heard of this "bleed" before, but I only really noticed it tonight and it made me think there MUST be some problem with the wiring.

When I play the neck pup in particular (although the bridge is the same to a lesser extent) its clearly lacking in gain compared to my other Duncan loaded guitars, like somethings not wired correctly.
I never changed the wiring at all when I replaced the pickups, so what could be causing this? A poor switch or pot?
Please gimme some help here, cos I love playing this cheapo guitar!

Thing is too, my band is wanting to do Back In Black and this thing sounds monstrous doing that riff, even if something IS wrong with the wiring! :smash:

 

[bigheadood]

Re: Wiring problem? Help please guys

Hmm. My les Paul only does this with the switch in the middle position, and one volume all the way down.

I can't really offer any help, except to say that something IS wrong with it.
Hopefully others will chime in.

Good luck

 

[Diocletian]

Re: Wiring problem? Help please guys

Well thanks, its a start!

 

[Artie]

Re: Wiring problem? Help please guys

Its not uncommon, on 4-wire pickups, to have a certain length of the red/white wires hanging outside of the ground sheath. It wouldn't be out of the question for there to be some bleed-over from one pup to the other, if the wires are lying right up against each other. (Highly possible in an LP.)

You could try just moving the wiring around somewhat inside the control cavity.

Edit: Having a less than ideal ground on either the volume pot or the pickups themselves can contribute to that symptom also.

 

[Diocletian]

Re: Wiring problem? Help please guys

Thanks Artie! I have the house free to myself tonight once the baby goes to sleep so I'll open the guitar up and see if any of the things you say are at play here.

 

[Diocletian]

Re: Wiring problem? Help please guys

Okay this is doing my head in now. I tried looking at grounds and stuff but it looks ok. I left the wiring as it was stock when I changed the pups and looking at the Duncan wiring diagram throws up a problem:
In the wiring diagram, where the left lug is used on the pots, my guitar is using the middle, and vice versa.

Could THIS be causing my problem? Do I really need to just strip the lot and rewire it as per the diagram?

 

[Artie]

Re: Wiring problem? Help please guys

Nah. That shouldn't be a problem. There's two ways to wire an LP, and you have one. The diagrams show the other.

The next thing to check is that the LP-style 3-way switch has open switch elements running parallel with each other, close together. If you're running fairly high gain, you could get some bleed-over through the switch. If its not too much trouble, just disconnect the "hot" lead from one pickup, at the switch temporarily and see if the problem goes away.

 

[Diocletian]

Re: Wiring problem? Help please guys

Nah. That shouldn't be a problem. There's two ways to wire an LP, and you have one. The diagrams show the other.

The next thing to check is that the LP-style 3-way switch has open switch elements running parallel with each other, close together. If you're running fairly high gain, you could get some bleed-over through the switch. If its not too much trouble, just disconnect the "hot" lead from one pickup, at the switch temporarily and see if the problem goes away.

Thanks again Artie, I appreciate your help. I've put the guitar and the soldering iron away for the night, but I'll try what you say tomorrow.
Do you think it could be that I need a new switch?

 

[Artie]

Re: Wiring problem? Help please guys

Do you think it could be that I need a new switch?

Depends. Are running high-gain? If so, it could just be the nature of the beast.

 

[Diocletian]

Re: Wiring problem? Help please guys

Depends. Are running high-gain? If so, it could just be the nature of the beast.

Yeah it's pretty high gain, but it seems to be a problem no matter what the gain is.
It seems to pretty much go away - although not completely - when I turn the respective tone controls down as well as the volumes.

Am I taking this too seriously? Is this really affecting the tone that much? It's really annoying me as the guitar is clearly not working as it should, but in real terms, does it matter?! :34:

 

[Diocletian]

Re: Wiring problem? Help please guys

BTW I did have bother with that switch before, it was crackling and stuff. I got it to stop that, I THINK, by spraying it with switch cleaner. Could THAT be a factor?

 

[Artie]

Re: Wiring problem? Help please guys

. . . but in real terms, does it matter?! :34:

If it bothers you . . . it matters. Is it fixable . . . maybe.

BTW I did have bother with that switch before, it was crackling and stuff. I got it to stop that, I THINK, by spraying it with switch cleaner. Could THAT be a factor?

Thats possible. Those contacts are still very close when the switch is "open". Not sure if age, per se., would exaborate the problem.

 

[Diocletian]

Re: Wiring problem? Help please guys

If it bothers you . . . it matters. Is it fixable . . . maybe.



Thats possible. Those contacts are still very close when the switch is "open". Not sure if age, per se., would exaborate the problem.

Okay so if I had sprayed too much gunk in there, it could lead to bleed through?
If I disconnect one hot lead and it goes away does it suggest I need a new switch? The switch isn't one of the sealed box type things, should I replace it with one of those?

 

[Artie]

Re: Wiring problem? Help please guys

No, thats not what I meant. The spray itself shouldn't hurt anything. I was thinking more in terms of the switch blades being bent from so much switch action. The "moveable" contact might be only a "paper-thin" distance from the other contact.

You could try a new switch, but I doubt that that fixes the problem. Double check all grounds before spending any money. Especially, the one on the 3-way switch. (It is grounded, right?)

 

[Diocletian]

Re: Wiring problem? Help please guys

No, thats not what I meant. The spray itself shouldn't hurt anything. I was thinking more in terms of the switch blades being bent from so much switch action. The "moveable" contact might be only a "paper-thin" distance from the other contact.

You could try a new switch, but I doubt that that fixes the problem. Double check all grounds before spending any money. Especially, the one on the 3-way switch. (It is grounded, right?)

I'm pretty sure everything is well grounded. BUt I put the guitar away in a rage earlier - I had it all apart, soldering iron in hand, and my baby daughter woke up and started going crazy. :dunce:

 

[Artie]

Re: Wiring problem? Help please guys

I know what you mean. Baby's hate noisy pickups.

 

[Robert S.]

Re: Wiring problem? Help please guys

The problem exists because you have the pickup leads wired to the wiper.

If you wire the pickups to the #3 terminal and the switch to the #2 (wiper) the problem will go away.

 

[Diocletian]

Re: Wiring problem? Help please guys

The problem exists because you have the pickup leads wired to the wiper.

If you wire the pickups to the #3 terminal and the switch to the #2 (wiper) the problem will go away.

Okay, this sounds promising. What's the "wiper" though?

 

[Robert S.]

Re: Wiring problem? Help please guys

You have 3 terminals on your volume pots. #1 is always grounded to chassis. #2 is in the middle and connects to the wiper. #3 is the terminal on the outside that is not grounded.

Connect your pickups to #3 and the switch leads to #2. By doing this you are grounding the switch/output jack when either pickup volume is turned to zero, silencing the guitar.

It is the wat production LPs are wired. You have a variation of the 50s wiring which does tend to bleed through a little as you are finding out.

 

[Diocletian]

Re: Wiring problem? Help please guys

You have 3 terminals on your volume pots. #1 is always grounded to chassis. #2 is in the middle and connects to the wiper. #3 is the terminal on the outside that is not grounded.

Connect your pickups to #3 and the switch leads to #2. By doing this you are grounding the switch/output jack when either pickup volume is turned to zero, silencing the guitar.

It is the wat production LPs are wired. You have a variation of the 50s wiring which does tend to bleed through a little as you are finding out.

Excellent! Thank you!
But you're saying genuine Gibsons are wired like this? Why? Seems really odd to me, like they're wiring in a fault for no reason..?