Excessive feedback from les paul custom

liamon

I'm having a bit of an issue with the heat coming out of my Les Paul Custom (stock, 1990). It's not something that I expected. The slightest touch of a distortion/fuzz pedal and it instantly goes into intense, squealing feedback. I've used the same amp/pedal rig with guitars with a range of pickups: bareknuckle warpigs (huge output), catswhisker wide range humbuckers, and some old bill lawrence humbuckers as well - and none of them give me any feedback at all with the same settings or distance from amp. 

I measured the output of the pickups with a muiltimeter on a lead plugged into the les paul (I know this is not the most accurate) - the neck is about 7k and the bridge is about 13k. So that all seems normal. 

Anyone had the same issues? Advice on minimising?

skunkwerx

Well its deffo the guitar then from your trouble shooting already.

Sounds like a symptom of the pickups going microphonic. 

If they have metal covers, the covers could be loose slightly which could cause it. 
Other than that it could be a few things that have come apart or loose in the pickup (from my limited experience). 

May be as simple as needing the pickups re-potted (if they were to begin with). 

SunDevil

Microphonics does indeed seem a likely culprit, although plugging into the amp direct and physically tapping the pickups will help confirm this (and which one)

What are the pickups? - 7k vs 13k is not a crazy difference, but it’s a pretty big gap and might indicate another issue

Winny_Pooh

repot

liamon

SunDevil said:

What are the pickups? - 7k vs 13k is not a crazy difference, but it’s a pretty big gap and might indicate another issue

They are stock pickups on a 1990 Les Paul Custom... so I don't know if they were potted to begin with (?). 

lewism

I had a 1990 LP Custom and it had the Bill Lawrence designed “circuit board” humbuckers. I think they’re made a little differently to normal humbuckers - you’re really not supposed to take the covers off them so not sure if they’re potted or not. Might be that they’re beginning to fail although I’m not sure what the reason would be. Mine didn’t have an issue with feedback.

Voxman

Microphonic pickups - need repotting.  

FelineGuitars

Could be simply microphonic , but as has been said they could be the Bill Lawrence designed ones with the PCB on the underside and they don't like being tampered with much at all if my memory serves me right

pinched from Les Paul forum:

Gibson HB-R (Alnico5) measured extremes between 7.0 - 9.1K
Gibson HB-L (Alnico5) measured extremes between 13.4 - 15.3K

As far as I can tell it's an even wind, and surprisingly thin on the wax, that is to say when one of my bobbins broke I couldn't detect any on the coilwire...

ICBM

I've never understood why these pickups have become somehow 'desirable' now that they're thirty years old... they were shit at the time and they're still shit now. They're poorly made, often go microphonic, and tend to wobble about because there is no height offset to the mounting feet.

Replace them with some good pickups and be done with it.

Actually, then sell them for a lot of money on Ebay to any fool who will pay good money for them...

(For what it's worth I like a lot of Bill Lawrence's pickups and wiring ideas - just not these.)

lewism

John Squire had them in one of the guitars he had made for the Spike Island gig, but I’m not sure if he still inspires enough hero worship to drive prices up. There are plenty of good options for a more conventional replacement though.

liamon

FelineGuitars said:

Could be simply microphonic , but as has been said they could be the Bill Lawrence designed ones with the PCB on the underside and they don't like being tampered with much at all if my memory serves me right

pinched from Les Paul forum:

Gibson HB-R (Alnico5) measured extremes between 7.0 - 9.1K
Gibson HB-L (Alnico5) measured extremes between 13.4 - 15.3K

As far as I can tell it's an even wind, and surprisingly thin on the wax, that is to say when one of my bobbins broke I couldn't detect any on the coilwire...

Just had a look and they are these Bill Lawrence ones. In that case I won't attempt a repot myself (which I was thinking of doing).

Can you elaborate on "they don't like being tampered with much at all"? Does that mean I should not have them repotted?

Might just switch them out with some vintage style bareknuckles and keep the BLs so I can revert back to original if need be.