Need some electronic advice

Battery_sxe

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Hey everyone!

So I am pretty nooby when it comes to tech stuff. With that being said I usually get even small stuff done at a repair shop.
I am currently rocking on a 2013 Gibson Les Paul Studio (left handed, not sure if this will matter for my questions).

I couple months ago I dropped my guitar off at a shop that I've used for a while and is supposed to be pretty trustworthy from their reviews and what I hear about from others. I dropped it off to get a new jack as mine was getting loose. When I came to pick it up, the tech told me the pickup switch wasn't grounded correctly so he charged me for that instead of the jack. Prior to this I was having no sound issues so it was a surprise to me. I take it home and I started having weird screeching feedback and my amp was picking up outside noises, later learning the term "microphonic". I do play with some pretty high gain amps so I know what the normal feedback would sound like. This was much worse. I brought it back to the shop and he told me my pickups were going bad. I found that weird that it would happen all of sudden and many of my music friends agreed. The tech recommended I get the pickups re-waxed. So I did it. He also was nice to also shield my electronic cavities for me.

Well I bring my guitar back and I am still having the same issues. I bought it to another guitar shop to look it over. They were honest and had no clue what it was as everything measured to what it should be. They told me my guitar has the 490r/498t pickups which are very hot pickups that can sometimes have that issue. We tried lowering the pickups and still the same issue.


So I guess I'm looking for help with 2 things:

1. I'm not one to blame a business for stuff. I just find it weird that this all happened after he "fixed" my pickup switch. Could there be a new wiring problem? I really don't want to blame him but could he have messed something up?

2. I also have a theory that maybe when my pickup switch wasn't grounded correctly I wasn't getting the full output of the pickups so I wasn't getting all that feedback. I am thinking of trying out new pickups that are maybe less hot. If that is the route I should try now, what pickups would you recommend? My main genre of music is punk/hardcore (ie. Minor Threat, Youth of Today, Backtrack etc.) which is played with a lot of driven high gain. What would be a good pickup to switch to that would have a high enough output, but not high enough where I can't control the feedback?


Thanks in advance!





Side note: Just thought I should add I've tried many different amps as I use what ever is available in the rehearsal room at the time my band has practice. Also tried using different cables and stuff, so I'm pretty sure its the guitar.
 

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DarrellV

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Hey everyone!

So I am pretty nooby when it comes to tech stuff. With that being said I usually get even small stuff done at a repair shop.
I am currently rocking on a 2013 Gibson Les Paul Studio (left handed, not sure if this will matter for my questions).

I couple months ago I dropped my guitar off at a shop that I've used for a while and is supposed to be pretty trustworthy from their reviews and what I hear about from others. I dropped it off to get a new jack as mine was getting loose. When I came to pick it up, the tech told me the pickup switch wasn't grounded correctly so he charged me for that instead of the jack. Prior to this I was having no sound issues so it was a surprise to me. I take it home and I started having weird screeching feedback and my amp was picking up outside noises, later learning the term "microphonic". I do play with some pretty high gain amps so I know what the normal feedback would sound like. This was much worse. I brought it back to the shop and he told me my pickups were going bad. I found that weird that it would happen all of sudden and many of my music friends agreed. The tech recommended I get the pickups re-waxed. So I did it. He also was nice to also shield my electronic cavities for me.

Well I bring my guitar back and I am still having the same issues. I bought it to another guitar shop to look it over. They were honest and had no clue what it was as everything measured to what it should be. They told me my guitar has the 490r/498t pickups which are very hot pickups that can sometimes have that issue. We tried lowering the pickups and still the same issue.


So I guess I'm looking for help with 2 things:

1. I'm not one to blame a business for stuff. I just find it weird that this all happened after he "fixed" my pickup switch. Could there be a new wiring problem? I really don't want to blame him but could he have messed something up?

2. I also have a theory that maybe when my pickup switch wasn't grounded correctly I wasn't getting the full output of the pickups so I wasn't getting all that feedback. I am thinking of trying out new pickups that are maybe less hot. If that is the route I should try now, what pickups would you recommend? My main genre of music is punk/hardcore (ie. Minor Threat, Youth of Today, Backtrack etc.) which is played with a lot of driven high gain. What would be a good pickup to switch to that would have a high enough output, but not high enough where I can't control the feedback?


Thanks in advance!





Side note: Just thought I should add I've tried many different amps as I use what ever is available in the rehearsal room at the time my band has practice. Also tried using different cables and stuff, so I'm pretty sure its the guitar.
First of all, :welcome: to the forum!

This is hands down the best collection of knowledgeable folks in the history of the interewebz!

(In my humble opinion, of course) We're glad you are here!

First rule is always post :photos:and lots of them.

We can't see your guitar from here, so pics help us to see what you have in front of you...

I will say it does sound rather odd... Normally on a Les Paul the switch is grounded through a bare metal ground wire back to the control cavity. Newer ones use a regular wire. Mine is green in the pic.

Like this...that green wire is soldered to the frame of the switch, not to any contacts.


On the other end it is soldered to ground in the CC (Control Cavity)



That should have never been an issue.

Not grounding the switch might introduce a bit of noise or hum, but won't change pickup volume..
 

Battery_sxe

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First of all, :welcome: to the forum!

This is hands down the best collection of knowledgeable folks in the history of the interewebz!

(In my humble opinion, of course) We're glad you are here!

First rule is always post :photos:and lots of them.

We can't see your guitar from here, so pics help us to see what you have in front of you...

I will say it does sound rather odd... Normally on a Les Paul the switch is grounded through a bare metal ground wire back to the control cavity. Newer ones use a regular wire. Mine is green in the pic.

Like this...that green wire is soldered to the frame of the switch, not to any contacts.


On the other end it is soldered to ground in the CC (Control Cavity)



That should have never been an issue.

Not grounding the switch might introduce a bit of noise or hum, but won't change pickup volume..
Hey thanks for the reply and welcome! I added some pics, not sure if it will help. Not really sure how to pull the switch out from the back as its mounted and I am hesitant to touch it lol.
 

cooljuk

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I appreciate the confidence but I couldn't diagnose a thing like this without having the guitar in front of me. Once it's been messed with, all bets are off. Connections were already failing, other connections were then tampered with, the pickups were removed and altered, the cavities were shielded.

Put it on my bench and I can make it right but it'd just be shots in the dark trying to determine the problem from a distance.




Some thoughts that may or may not be of any help to the OP or anyone else...

Output jacks usually fail because the round sleeve of the jack becomes stretched into an oval and fails to make a proper ground connection. This happens from pulling the cable to the side. The best fix for this is to replace the TS jack with a TRS jack, using the ring connection as an additional ground point. Then, regardless of the shape of the sleeve where the plug enters, you've still got a ground. It'll last MUCH longer.

The output jack and PU switch are grounded to the same place. Could just be a difference of terminology and misunderstanding between you and the tech. Perhaps the same thing you described was actually addressed?

There's almost never a reason to re-pot a pickup, unless it has been taken apart, had the cover off, or a coil replaced. Under the absolute best efforts of the determined, enough wax can't be removed to cause a potted pickup coil to become unpotted and oscillate. A single molecule layer of wax between neighboring turns of the coil wire is all that is needed to bind them together and prevent oscillation.

Foil shielding often causes more harm than good. Guitars run fine without it. Especially guitars with Gibson style humbuckers with shielded metal casings and baseplates and shielded hookup leads on the pickups, switch, and jack. Shielding with foil (or even paint) can create a capacitive effect and introduce another potential point of oscillation. If the foil vibrates sympathetically to SLP from the environment or resonance of the guitar, you've created a condenser microphone.
 

efstop

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I appreciate the confidence but I couldn't diagnose a thing like this without having the guitar in front of me. Once it's been messed with, all bets are off. Connections were already failing, other connections were then tampered with, the pickups were removed and altered, the cavities were shielded.

Put it on my bench and I can make it right but it'd just be shots in the dark trying to determine the problem from a distance.




Some thoughts that may or may not be of any help to the OP or anyone else...

Output jacks usually fail because the round sleeve of the jack becomes stretched into an oval and fails to make a proper ground connection. This happens from pulling the cable to the side. The best fix for this is to replace the TS jack with a TRS jack, using the ring connection as an additional ground point. Then, regardless of the shape of the sleeve where the plug enters, you've still got a ground. It'll last MUCH longer.

The output jack and PU switch are grounded to the same place. Could just be a difference of terminology and misunderstanding between you and the tech. Perhaps the same thing you described was actually addressed?

There's almost never a reason to re-pot a pickup, unless it has been taken apart, had the cover off, or a coil replaced. Under the absolute best efforts of the determined, enough wax can't be removed to cause a potted pickup coil to become unpotted and oscillate. A single molecule layer of wax between neighboring turns of the coil wire is all that is needed to bind them together and prevent oscillation.

Foil shielding often causes more harm than good. Guitars run fine without it. Especially guitars with Gibson style humbuckers with shielded metal casings and baseplates and shielded hookup leads on the pickups, switch, and jack. Shielding with foil (or even paint) can create a capacitive effect and introduce another potential point of oscillation. If the foil vibrates sympathetically to SLP from the environment or resonance of the guitar, you've created a condenser microphone.
So, I'll use my copper tape for decorative use around my apartment, then, and won't bother taking my SG Special apart :D

Good to know. What about just copper taping the inside of the P-90 plastic covers, staying back a half mm or so from the pole holes?
 

Battery_sxe

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I appreciate the confidence but I couldn't diagnose a thing like this without having the guitar in front of me. Once it's been messed with, all bets are off. Connections were already failing, other connections were then tampered with, the pickups were removed and altered, the cavities were shielded.

Put it on my bench and I can make it right but it'd just be shots in the dark trying to determine the problem from a distance.




Some thoughts that may or may not be of any help to the OP or anyone else...

Output jacks usually fail because the round sleeve of the jack becomes stretched into an oval and fails to make a proper ground connection. This happens from pulling the cable to the side. The best fix for this is to replace the TS jack with a TRS jack, using the ring connection as an additional ground point. Then, regardless of the shape of the sleeve where the plug enters, you've still got a ground. It'll last MUCH longer.

The output jack and PU switch are grounded to the same place. Could just be a difference of terminology and misunderstanding between you and the tech. Perhaps the same thing you described was actually addressed?

There's almost never a reason to re-pot a pickup, unless it has been taken apart, had the cover off, or a coil replaced. Under the absolute best efforts of the determined, enough wax can't be removed to cause a potted pickup coil to become unpotted and oscillate. A single molecule layer of wax between neighboring turns of the coil wire is all that is needed to bind them together and prevent oscillation.

Foil shielding often causes more harm than good. Guitars run fine without it. Especially guitars with Gibson style humbuckers with shielded metal casings and baseplates and shielded hookup leads on the pickups, switch, and jack. Shielding with foil (or even paint) can create a capacitive effect and introduce another potential point of oscillation. If the foil vibrates sympathetically to SLP from the environment or resonance of the guitar, you've created a condenser microphone.

I'm pretty sure he just meant the PU switch itself. There was nothing wrong with it prior aside from my jack being loose as it got old. That wasa my only reason for bringing it in. It wasn't until after I picked it up these issues started so I'm just curious if he could have touched something by accident. Also there was no shielding prior to this issue. He added shielding after I told him about the new feedback in an attempt to fix the feedback issue, even though it didn't do anything. So I'm just very confused what would trigger this new screeching type feedback I have now lol
 
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DarrellV

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So I'm just very confused what would trigger this new screeching type feedback I have now lol
Will it do this on an amp at his place? If it does, simply bring it to him, plug it in, and say there! It didn't do this before, fix it!
 

Battery_sxe

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Will it do this on an amp at his place? If it does, simply bring it to him, plug it in, and say there! It didn't do this before, fix it!
Unfortunately it does not do it there as they don't really have any high gain amps in the shop. He will plug in through a distortion or overdrive pedal and hear the feedback a little but then claims that just what happens to it when you play high gain. After going back and forth a few times now at this point I think its safer to not even let him touch the guitaranymore. He seems to not believe me on what the issue is. The other shop was able to understand but wasn't sure what it could be.
At this point I'm accepting the damage and will be willing to put money in to get it fixed as it is my favorite guitar. That is why I am also looking into new pickups. I have googled and saw online that people often have similar issues with these 498t pickups as they are very hot. I'm thinking maybe if I get a lower output humbucker, it can maybe almost cover up the issue (while also hopefully not losing the sound I love from this guitar).
 

DarrellV

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Lets start with narrowing it down a bit..

Does the switch work as it should.

Do both pickups squeal or only one?

Do you plug straight in to the amp or is there a stomp box?

If so, let's remove the box and try it.

Can you test each pickup by tapping it with a non metal object to test the covers for micro phonics..

Can you pull the pickups and give us a photo of the undersides?

You can pull the pickup plugs out of the PC board and plug it in and crank it.

It should do nothing, of course.. Tap the snot out of it and wiggle stuff including the jack to see if anything shakes loose and makes noise...
 

Battery_sxe

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Lets start with narrowing it down a bit..

Does the switch work as it should.

Do both pickups squeal or only one?

Do you plug straight in to the amp or is there a stomp box?

If so, let's remove the box and try it.

Can you test each pickup by tapping it with a non metal object to test the covers for micro phonics..

Can you pull the pickups and give us a photo of the undersides?

You can pull the pickup plugs out of the PC board and plug it in and crank it.

It should do nothing, of course.. Tap the snot out of it and wiggle stuff including the jack to see if anything shakes loose and makes noise...

So the pickup switch does work, and it always has even before dropping it off at this shop.

Both pickups do squeal, and pretty equally too. I would assume the bridge would sound worse than the neck, or maybe I'm wrong. But they are both bad.

I've tried plugging it in both into the amp and through an OD pedal. The OD does make it a little worse but without it, the feedback is still pretty bad. I've have a couple OD pedals and tried it with each.

As far as tapping the pickups, this is what I believe led the first tech and I to thinking they were microphonic. Tapping with something as small as my pick you can hear clearly through any amp I use. Not only tapping it but I can also get outside noises with it sometimes. Not all the time but if my drummer hits his cymbals sometimes the screech will get sharper (if I'm strumming while he plays), if that makes sense. This is what is still really making me think it is the pickups. But re-waxing them made no difference.

As far as pulling out the pickups and taking a picture, I'll be honest as I am very inexperienced with taking apart things like that so I'm going to have to pass on doing that for now haha.

I know its hard to diagnose from this especially if the guitar isn't in front of you so please don't stress over my issue! I was more trying to see if it was a simple and common issue people had. If there is nothing you can think of, no sweat! And thank you all for trying to help! :)
 

DarrellV

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So the pickup switch does work, and it always has even before dropping it off at this shop.

Both pickups do squeal, and pretty equally too. I would assume the bridge would sound worse than the neck, or maybe I'm wrong. But they are both bad.

I've tried plugging it in both into the amp and through an OD pedal. The OD does make it a little worse but without it, the feedback is still pretty bad. I've have a couple OD pedals and tried it with each.

As far as tapping the pickups, this is what I believe led the first tech and I to thinking they were microphonic. Tapping with something as small as my pick you can hear clearly through any amp I use. Not only tapping it but I can also get outside noises with it sometimes. Not all the time but if my drummer hits his cymbals sometimes the screech will get sharper (if I'm strumming while he plays), if that makes sense. This is what is still really making me think it is the pickups. But re-waxing them made no difference.

As far as pulling out the pickups and taking a picture, I'll be honest as I am very inexperienced with taking apart things like that so I'm going to have to pass on doing that for now haha.

I know its hard to diagnose from this especially if the guitar isn't in front of you so please don't stress over my issue! I was more trying to see if it was a simple and common issue people had. If there is nothing you can think of, no sweat! And thank you all for trying to help! :)
OK, no problem...

The pickups come out with the 4 screws on the plastic ring. You should take the strings off first.

Should lift right out like this.


There are a couple things we can check once you get them out.

Flip them over and look at the bottom.

These are 498's they should look like this.


I think I know what's wrong now, it's possible the tech did not fasten the covers down properly after his 're-waxing' job.

Which as cooljuk has said, was pointless...

Pictures of yours at this point will help a lot, but first see if he re-soldered the covers back on.

Those solder blobs in the middle near each edge are there to fasten the cover over the pickup.

If there is a gap between the coil inside and the cover, and I think that is likely what is causing your problem, it will squeal at gain and the covers will be overly sensitive like yours are.

If it is not soldered that would also add to the problem.

There is also a possibility that the bobbin screws are loose allowing the coils to vibrate with sound.

Those 4 phillips head screws hold the plastic bobbins (coils) down.



Make sure they are snug, not loose at all. They go into plastic, so just a gentle nudge.

I think we are on the road to recovery, but you will have to pull the pickups at this point.

4 screws, lift up. That's all there is to it. Then photos of the back of them. We'll have ya fixed in a jiffy if its what I think it is...
 


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