Shielding and Gibson-style braided cables

[TeaAt5]

Hi All!

I have just had a Seth set installed in my LP Studio, and now I am having trouble with hum and buzz. There is a nasty, nasal low-pitched buzz, and when I take my hand of the strings/bridge, I get another high-pitched buzz as well. It hums, but I can deal with hum. I can't deal with a buzz-saw accompanying my quiet notes.

I am thinking of pulling all of the hardware out and painting all the cavities with shielding paint (or use copper tape, whichever hits my mailbox first!), and possibly replacing all of the old hardware with a rewire harness kit.

I have noticed that the original pickup cable was the one with the braided ground on the outside, but the black SD cables aren't shielded like this. Could this be the cause of the buzz?

Also, the tech who installed it left a lot of the cable wound up in the cavity, could this be picking up something? I hear a slight pulse at times, which could be RF in my house somewhere, but I have only had this problem since the pickup replacement, and nothing else has changed in my setup. I also get the same problem in a SS amp as well as my HRD, so it's not the amp.

Is it possible/worth getting a braided cable? Can you surround the cable with some sort of shielding sleeve?

 

[Jeff_H]

Re: Shielding and Gibson-style braided cables

Hello TeaAt5.....

Normally the Seth Lovers do come with the vintage braided output cable, but you can't use coil tap/parallel/series options with that kind of lead. That's why you ordered the Seth's with 4 conductor cable, so you could coil split. The black surround wire is insulation and each individual wire inside is shielded individually, except for the ground wire which is always bare. So, the black 4 conductor wire will not be your source of hum on it's own and doesn't require the addition of more shielding.

As for the tech leaving the extra length of the lead, that is done purposely for a very good reason; especially on replacement pickups. If he were to cut the leads to just the right length and then later you wanted to take them out and put them in another guitar, the leads might be too short. Also, since they're replacement pickups, if you ever wanted to put the stock pickups back in and sell the Seth's, it would be harder with shorter leads. People want to buy used pickups with as much lead as possible, so your tech did the right thing there. As for the extra wire causing problems just being in there, it's normally not an issue on it's own either.

Now, I'm not the wiring expert here, but to me it sounds like a bad ground or even perhaps a wire hooked up incorrectly. There will be others who can diagnose your wiring problem better than I, but we'll need some high quality pics of the control cavity, so we can see what's hooked up where.

With the 4 conductor cable, the green and bare wires should be together and go to ground, back of pot usually. The black is hot and goes to the volume pot, left hand lug if you're looking down on it as installed in your guitar. The red and white wires are used for splitting, and that's where my experience ends. Others can tell you where they should go.

My guess is that your tech has one of the colored wires in the wrong spot. Maybe the green and bare aren't grounded together or he used red as hot instead of black. SD color codes are not the same as Dimarzio or some other pickups, so if your tech isn't familiar with SD pickups I think he may have hooked them up wrong.

Like I said, some of the other guys can help out better than I can. Get us some pics and we'll do what we can to help.

 

[Darg1911]

Re: Shielding and Gibson-style braided cables

Gibson doesn't shield the cavities but it's funny how this stuff works. I have a Gibson LP Tribute that hum-buzzed like crazy. Stock pups were Dirty Fingers. But it was noisy with everything I put in there, covered or uncovered, multiconductor wired pickups or or vintage braid. And it wasn't the factory PCB or wiring harnesses, those were pulled and replaced with individual pots and it still buzzed. I have a Godin dual bucker guitar that was the same way (though I never swapped pups in that one). On the other hand, my Gibson LP Traditional is quiet and it's not shielded either. So, while I'd like to say that I think the pickups contribute (to some degree), I'm not so sure that they do ... which in your case is why I'd make sure the wiring was done right first. Since I know my wiring is right when I do it, I went to shielding paint on the Godin. Worked a treat. Used copper tape on the LP Traditional. Also worked a treat. The paint is easier to work with but it's permanent. I used the tape on the LP just so it could be restored back to original. It's only a Tribute but I felt better about doing it that way. These aren't the only guitars I've shielded. I've used the paint on several in the past. Many of the imports I've had/have had the shielding paint from the factory. They've all been quiet.

You may get some members here who will tell you that shielding doesn't work. It will depend on your wiring being correct and may very well depend on what the source of interference is that is causing your "buzzing". But, it's worked for me every time I've done it and it's always been a significant improvement.

Again, make sure your wiring is correct before you make the effort.

 

[ehdwuld]

Re: Shielding and Gibson-style braided cables

Jack

It's the jack

Its wired backwards

It's the jack

The jack

 

[Darg1911]

Re: Shielding and Gibson-style braided cables

If the jack is wired backwards, that would do it. But if that's the case, it should be noisier when touching the strings ... I think.

 

[Ayrton]

Re: Shielding and Gibson-style braided cables

Jack or bad ground. Take it back to the installer

 

[Mincer]

Re: Shielding and Gibson-style braided cables

^ Either of these. Try it in a different location. Some places are just really noisy- in the studio where we rehearse, humbuckers still hum, but nowhere else. But if it is the guitar's fault, it never should have left the tech's bench like that.

 

[dystrust]

Re: Shielding and Gibson-style braided cables

Jack or bad ground. Take it back to the installer

^ Either of these. Try it in a different location. Some places are just really noisy- in the studio where we rehearse, humbuckers still hum, but nowhere else. But if it is the guitar's fault, it never should have left the tech's bench like that.

Both of these.

To add to Mincer's point, if it's a problem with where you're playing I'd expect any guitar to hum to some extent.

 

[Ayrton]

Re: Shielding and Gibson-style braided cables

it never should have left the tech's bench like that.

This

 

[TeaAt5]

Re: Shielding and Gibson-style braided cables

Thanks everyone, I appreciate the support.

Here is how it came back, it looks like some bad soldering to me:



So I fixed it... I think...





TBH it's all a bit messy. Just now I fiddled with the wires and there is definitely a break in there. I think I might have melted out one of the pot lugs. So today I might just gut the whole thing and rewire it myself.

 

[TeaAt5]

Re: Shielding and Gibson-style braided cables

Well the bridge pot was clearly damaged so I've pulled everything out to start fresh.

Out of interest, if I wanted to connect straight to a guitar jack from the pickup wire, is just white and black? does the ground wire go to black? If I do this and it STILL hums, does that indicate poor soldering at the pickup/TS end?

 

[Darg1911]

Re: Shielding and Gibson-style braided cables

This is basic LP wiring with SD 4 conductor humbuckers.

Notice that the red and white wires are connected together and taped off. Black is hot. Green and bare are connected together as ground.

 

[psecustoms]

Re: Shielding and Gibson-style braided cables

Hey Tea the copper shielding or insulation does nothing to solvethe problem you are having ,especially on a les paul, Its the way they are wired. You basically have too many ground loops in your pk up cavity. I see it everyday on every make of guitars . Braided wires have nothing to do with your noise. The amp you that you plug into and your pedals probably have poor or not enough grounds, where your gtr has too many and you are basically amplifying ground loops.

 

[TeaAt5]

Re: Shielding and Gibson-style braided cables

OK, I'm going to get rid of the ground plate and wire things directly. Will be a good exercise.

I think I'll keep the wiring of the jack though, as it has braided cable and I want to keep that.

 

[Artie]

Re: Shielding and Gibson-style braided cables

I wouldn't lose the ground plate. It's not your problem. Ground loops virtually never happen within the confines of a guitar. There just isn't enough current flow to cause them. But bad grounds are commonplace. You definitely need to clean up that wiring.

The black surround wire is insulation and each individual wire inside is shielded individually, except for the ground wire which is always bare. So, the black 4 conductor wire will not be your source of hum on it's own and doesn't require the addition of more shielding.

Hey Jeff. Just on a technical note, that's not quite right. All four internal wires are shielded as a group by a foil wrapper that's in contact with the bare wire for the whole length of the cable. So, if you ground the bare wire, you've shielded the whole cable. Each individual wire is not shielded, but they don't need to be.

Artie

 

[Darg1911]

Re: Shielding and Gibson-style braided cables

Maybe I'm blind but aside from the slop, I'm seeing the bare wire with the black wire from the pickups soldered to the back of the pots. I'm seeing the white wire soldered to the pot inputs and I don't see the red wire at all. These are supposed to be 4 conductor Duncans.

What am I missing?

 

[Artie]

Re: Shielding and Gibson-style braided cables

I'm seeing the bare wire with the black wire from the pickups soldered to the back of the pots. I'm seeing the white wire soldered to the pot inputs and I don't see the red wire at all.

Yup. I see that too. It almost appears as though they're in single coil mode. That would definitely cause the hum/buzz.

 

[Darg1911]

Re: Shielding and Gibson-style braided cables

Yup. I see that too. It almost appears as though they're in single coil mode. That would definitely cause the hum/buzz.

Forgot ... I see no green wire either. So, no green or red wire visible. Maybe the "tech" cut them both back flush with the cables outer jacket???? Or, maybe they aren't Duncans?

 

[TeaAt5]

Re: Shielding and Gibson-style braided cables

Well, I pulled it all out and painted the cavity with two coats of shielding paint. I put in new CTS pots and normal cheap caps. I put about three layers of copper tape on the cover, and also covered the wire holes with copper tape.

Hello silence* my new friend.

*relative... actually silent with hand on bridge. Tiny, barely perceptible hum without.

Very happy with my first rewire!

Thanks once again for all the help and advice everyone!!!


Sent from my iPhone using Tapatalk

 

[Darg1911]

Re: Shielding and Gibson-style braided cables

Glad you got it sorted out. Still not sure you have the pickups wired quite right (assuming they are Duncans) but someone else can take a close look.

I like to use a piece of 18 or 20 gauge buss wire to connect the pot cases rather than individual wires. It doesn't work any better than the individual wires that you used, but it's a bit neater and easier because you don't have to worry about the insulation at all. You just run one, continuous piece and form it so it's out of the way.

Attached photo just to show example of the buss wire.