Re: Jag with a noise problem.. bad earth?

Laika · Post by **Laika** » Tue Mar 20, 2007 7:27 pm

Hi all,

I recently picked up my first offset .. a nice sunburst CIJ Jag with hot SD's. So far I'm loving it except its got a noise problem. When I'm not touching anything metal it has a "bad earth" type of noise. With the pickups both in the off pos it is at its worst by far, it sounds like you right next to a pc monitor (but I'm not). Yesterday I restrung it and was setting up the bridge so I had all the plates off looking for a broken wires etc but everything looks good. The scratch plate is foil backed but that is the only shielding it has (will copper foil the body cavities soon).

Can anyone point me in the right direction to track this down?

Post by **mynameisjonas** » Wed Mar 21, 2007 3:25 am

the first thing i would check is the wire going from the back of the volume pot to the trem cavity. it should be touching the bottom of the trem plate. it usually isn´t stapled so it´s possible it has simply fallen out of place during assembly.

Laika · Post by **Laika** » Wed Mar 21, 2007 4:16 am

mynameisjonas wrote: the first thing i would check is the wire going from the back of the volume pot to the trem cavity. it should be touching the bottom of the trem plate. it usually isn´t stapled so it´s possible it has simply fallen out of place during assembly.

I was hoping that connection was the problem when I opened it all up. I even gave the wire and underside of the trem plate a bit of a scraping to make sure it had a good contact, no change

Pumpkin · Post by **Pumpkin** » Thu Mar 22, 2007 12:37 am

Sounds like some n00b has wired the jack positive to ground and ground to positive,this makes that noise but i cant tell with out seeing ALL of your wiring.I doubt its like this but if its grounded properly its something like this in there some where.

You have Photos of all the wiring? we can fix it if ya do

Laika · Post by **Laika** » Thu Mar 22, 2007 6:49 pm

Pumpkin wrote: You have Photos of all the wiring? we can fix it if ya do

Here are some I took when I restrung it

1946dodge · Post by **1946dodge** » Thu Mar 22, 2007 7:26 pm

You may have to look for "cold " solder joints - like wires soldered to the pot cases. Sometimes just remelting the solder with a hot iron will make complete contact. Also, make sure all wire connections are covered with solder.
My Jag Baritone does the same thing. Check when you play it. Night time the street lights or a noisy public transformer can cause noise.

I once had a nice tube radio I restored and when I turned it on at night, the godamn street lights or some public utility shit outside was radiating noise and I thought it was the radio.
So I did more rewiring of the radio and screwed it up.
I found later that it was the outside noise.
Take your guitar to another location and try it too.

Laika · Post by **Laika** » Thu Mar 22, 2007 8:05 pm

1946dodge wrote: You may have to look for "cold " solder joints - like wires soldered to the pot cases. Sometimes just remelting the solder with a hot iron will make complete contact. Also, make sure all wire connections are covered with solder.

None of the joints look suspect but I know that doesn't mean much

1946dodge wrote: My Jag Baritone does the same thing. Check when you play it. Night time the street lights or a noisy public transformer can cause noise.
I once had a nice tube radio I restored and when I turned it on at night, the godamn street lights or some public utility shit outside was radiating noise and I thought it was the radio.
So I did more rewiring of the radio and screwed it up.
I found later that it was the outside noise.
Take your guitar to another location and try it too.

I don't think its an environment problem, I took it to my brother home studio to try and its still constantly noisy (not effected by monitors/speakers etc)

Pumpkin · Post by **Pumpkin** » Thu Mar 22, 2007 9:01 pm

From looking at the photos it looks fine to me,everythings where it should be so............i have no idea!

You could try testing every inch of the circuits with a multi meter if you have one,test the pups individually too!

Cold solder? could well be, but they look fine.

I really have no idea dude!

Some one may propose the answer yet!

Edit: Are the claws wired to the earth wire of the pup? Stupid question but some people make this mistake and wire it to hot instead!

I ask cause i noticed the pup leads aren't original,they look AV,so the claw thing is a possibility.

Laika · Post by **Laika** » Thu Mar 22, 2007 9:58 pm

Pumpkin wrote: From looking at the photos it looks fine to me,everythings where it should be so............i have no idea!

You could try testing every inch of the circuits with a multi meter if you have one,test the pups individually too!

Cold solder? could well be, but they look fine.

I really have no idea dude!

Some one may propose the answer yet!

Edit: Are the claws wired to the earth wire of the pup? Stupid question but some people make this mistake and wire it to hot instead!

I ask cause i noticed the pup leads aren't original,they look AV,so the claw thing is a possibility.

I was told the pickups are hot seymour duncan's by the seller (anyone know how to tell if they are? I can't see any markings on them) and yeah the claws are wired to earth ok.

Pumpkin · Post by **Pumpkin** » Thu Mar 22, 2007 10:26 pm

Unless the owner replaced the leads with yellow,white and black cloth wire, they are not SD hot! SD hot use plastic wire.
Without seeing them I would say they are AV as not too many people change pickup wire but lots tell lies!

Well dude,if the claw is wired to the black wire and everything else is fine,you may need to multi meter it because jaguars dont make any noise when both pups are off,and the noise it makes when one is on varies depending on location and interference.

One other thing...are all the chrome plates and on/off switches connected to a common ground? Meaning they should all go back to the pot,and be one ground.

Laika · Post by **Laika** » Thu Mar 22, 2007 11:02 pm

Pumpkin wrote: Unless the owner replaced the leads with yellow,white and black cloth wire, they are not SD hot! SD hot use plastic wire.
Without seeing them I would say they are AV as not too many people change pickup wire but lots tell lies!

..

... Grrrr

AV = American Vintage?

Here is a pic of the bridge pickup

Pumpkin wrote: Well dude,if the claw is wired to the black wire and everything else is fine,you may need to multi meter it because jaguars dont make any noise when both pups are off,and the noise it makes when one is on varies depending on location and interference.

One other thing...are all the chrome plates and on/off switches connected to a common ground? Meaning they should all go back to the pot,and be one ground.

All the ground wires go back to the vol pot. I guess I'll borrow a meter and see what I can find.

Pumpkin · Post by **Pumpkin** » Fri Mar 23, 2007 5:11 pm

That pic creates more confusion because the claws look CIJ not AV,the pups could be SD or AV,but if they're AV why put CIJ claws on 'em when AV pups are sold with the claw and cover already attached.

That sticker "1B" is your best bet at finding out what they are! Maybe someone knows about this???????

SD pups go sjag...1,2,3, so 1b to me would mean SJAG1 or "vintage for jaguar" presuming they're SD to begin with that is.

Get a ohm meter and measure across the pups pos & neg leads and check the resistance,hot would be 12.31 and 11.5k whereas vintage would be 6.5 and 6.8k.give or take a tiny bit.

Personally i think they're SJAG1's but this doesn't solve your buzz problem does it!

Laika · Post by **Laika** » Fri Mar 23, 2007 9:11 pm

Pumpkin wrote: That pic creates more confusion because the claws look CIJ not AV,the pups could be SD or AV,but if they're AV why put CIJ claws on 'em when AV pups are sold with the claw and cover already attached.

Will a AV claw drop into a CIJ scratch plate ok? If not maybe thats why they kept the CIJ claws... If they are the same size its got me stumped.

Pumpkin wrote: That sticker "1B" is your best bet at finding out what they are! Maybe someone knows about this???????

SD pups go sjag...1,2,3, so 1b to me would mean SJAG1 or "vintage for jaguar" presuming they're SD to begin with that is.

Get a ohm meter and measure across the pups pos & neg leads and check the resistance,hot would be 12.31 and 11.5k whereas vintage would be 6.5 and 6.8k.give or take a tiny bit.

Personally i think they're SJAG1's but this doesn't solve your buzz problem does it!

I was hoping the "1B" sticker would help identify it, the neck P/U has no sticker.

As soon as I get the time to open it up again I'll get a meter on it, not only do I need to get the hum sorted now I also want to find out just what sort of pickups I have.

Something I've just noticed is some strange (to me) goings on with the vol pot/hum... With both P/U's "off" the vol pot rolls off the hum like I expect it should. With any/or both P/U's on in the last 1/8th of a turn towards max the hum changes from the usual low hum to a "much" higher freq hum.... HHmmm now I'm confused even more

1946dodge · Post by **1946dodge** » Fri Mar 23, 2007 9:14 pm

I just read a post on the Loyal order of the Big Cat on the FDP site, one of the last posts.
The guy noted a hum in his jag baritone custom. He rolled up a piece of foil and stuck it under the triple switch plate to shield the wires by grounding the pickguard foil itself or something to that effect. You might want to try that.
Let us know if you do and if it works. If I have time I will try it too on mine.
Ed
http://www.fenderforum.com/forum.html?d ... offset=872
post by hapsh:

I just rolled in here too, I used to post back when we called it a Jag Baritone. I had no idea until today that the Big Cat thread was about the Jag Baritone. As for the hum on these guys, I found that they skimped on the pickups and did not reverse wind reverse pole one of the pickups, so they hum even with both on. I did however find a good way to reduce the hum greatly. It seems the pickguard is foil backed but NOT GROUNDED. I fixed that by putting a piece of rolled foil under the 3 way switch plate and the pickguard, effectively grounding the pickguard. Now the hum on mine is reduced substantially and is not really a problem anymore. It makes sense, the pickups are already shielded with the combs, so all was needed was shielding of the wires. Oh, and I also wax potted the stock pickups to kill potential squeal, although I never had an issue

Laika · Post by **Laika** » Mon Apr 16, 2007 1:29 am

Have I found my problem? ... Do CIJ Jag's come standard with body shielding?

To cut a long story short, the inside of my pickup and jack control plate routing has either conductive paint or a very neat foil shield that has been painted over... and its not connected to earth

... So if I touch anything earthed my noise goes away, if I touch the unearthed cavity shielding the noise gets worse (a lot) and if I join the two the noise stops.

Is that it?... the unearthed shielding is working as an antenna for noise?

I've had a bit of a look but cant find where the shielding should connect to earth? Whats the best way to connect it up?