• Guys, we've spent considerable money converting the Les Paul Forum to this new XenForo platform, and we have ongoing monthly operating expenses. THE "DONATIONS" TAB IS NOW WORKING, AND WE WOULD APPRECIATE ANY DONATIONS YOU CAN MAKE TO KEEP THE LES PAUL FORUM GOING! Thank you!

1954 P-90 Squeal Problem

Emerald

New member
Joined
Dec 5, 2007
Messages
1,123
I have been extremely lucky with my early fifties P-90's. Never had a squeal or microphonic issues... Didn't a little Dutchboy in SoCal pot a PAF style pickup back in the day methinks,,:dude: :dude:
d5afb26a.jpg

e1864a65.jpg

:jim :jim :dude:
yngwie308
 

Electric Lloyd

Active member
Joined
Feb 5, 2005
Messages
3,500
Anyone have any experiance with having a "squealing" pickup rewound with it's origonal wire? If a loose wind can be a culpret, a fresh & tighter rewind using the stock wire may be an option......
 

In The Light

New member
Joined
Mar 31, 2005
Messages
609
Anyone have any experiance with having a "squealing" pickup rewound with it's origonal wire? If a loose wind can be a culpret, a fresh & tighter rewind using the stock wire may be an option......

That would alter the original character of the pickup much more than potting. "Fresh & tighter" are practically never positive attributes regarding pickup windings. Loose winds are one of the best ways to lessen capacitance and inductance, and looser winds add to the beneficial microphonics we are talking about in this thread. You absolutely want to wax pot and don't want to rewind tighter IMO, and in electronics theory.
 
Last edited:

In The Light

New member
Joined
Mar 31, 2005
Messages
609
The reason the pickup can act as a microphone is because incoming sound waves agitate the windings in the coil. Their tiny movements through the magnetic field cause an electric signal. It's called a positive feedback loop. Once you wax pot that coil, all internal movement stops, and all of the acoustic properties are lost.

I have a situation that contradicts this conventional wisdom on potting. I have one Les Paul with '57 Classics (installed in '99) that sound very "alive", EVEN though they are wax potted. On top of this my pickups are microphonic too - I can yell (just talking won't do it) into my pups or put the guitar face in front of a speaker, and it will amplify. So, how is this - why are my wax-potted '57 Classics microphonic too? Are there varying degrees of loss because of certain types of waxing? Is there an element of chance, etc?
 

Electric Lloyd

Active member
Joined
Feb 5, 2005
Messages
3,500
That would alter the original character of the pickup much more than potting. "Fresh & tighter" are practically never positive attributes regarding pickup windings. Loose winds are one of the best ways to lessen capacitance and inductance, and looser winds add to the beneficial microphonics we are talking about in this thread. You absolutely want to wax pot and don't want to rewind tighter IMO, and in electronics theory.

Shows ya how much I know about pickups! :rofl Thanks for the info!:salude
 

Tele-Bob

New member
Joined
Jan 26, 2004
Messages
121
My '55 Custom has a little "chime" on the bridge pickup. It's quite managable still and often useful!
 

bfisher690

New member
Joined
Apr 26, 2009
Messages
80
Gotta resurrect this one!

I have a '53 Les Paul with a killer bridge pickup but with a majorly microphonic p-90 in the neck. With my tweed Deluxe turned up, it just gets the high pitch squeal thing happening like crazy.

So, I will not be potting this one. BUT, I do want to wax the magnets and maybe put something under the pickup.

What should I tell my tech. How do you wax the magnets properly?

Also, has anyone tried tight rubber band or a tied string around the tape that covers the coil. Could that tighten it up without having to remove the tape and tighten it?

Thanks so much. I want to do as much as I can up to the point of potting it. I have done that, and the pickup, to me, breathes less and I do seem to lose detail in the upper mids and top end.

Thoughts?

Thanks!

Brian
 

MapleFlame

Well-known member
Joined
Jul 3, 2005
Messages
14,044
Gotta resurrect this one!

I have a '53 Les Paul with a killer bridge pickup but with a majorly microphonic p-90 in the neck. With my tweed Deluxe turned up, it just gets the high pitch squeal thing happening like crazy.

So, I will not be potting this one. BUT, I do want to wax the magnets and maybe put something under the pickup.

What should I tell my tech. How do you wax the magnets properly?

Also, has anyone tried tight rubber band or a tied string around the tape that covers the coil. Could that tighten it up without having to remove the tape and tighten it?

Thanks so much. I want to do as much as I can up to the point of potting it. I have done that, and the pickup, to me, breathes less and I do seem to lose detail in the upper mids and top end.

Thoughts?

Thanks!

Brian

I think you may have a gap under the baseplate or between the bobbin and baseplate. It might be as simple as loosening the two screws under the baseplate and carefully re-tighten them. Also could cut two small strips of thin rubber to fit over the pole piece channel top and then place the bobbin back on top. :)
 

DANELECTRO

Well-known member
Joined
Feb 24, 2003
Messages
6,317
One of the P90s on my Special had a serious squeal problem. I found that the bobbin was slightly loose and simply tightening the screws that hold it to the baseplate cured it.
 

johnnyjellybean

Active member
Joined
Dec 23, 2001
Messages
1,030
We were just talking about the microphonic qualities of the earlier 50's P-90s being a plus if the wood is good.

here:
http://www.lespaulforum.com/forum/showthread.php?t=142442




I've heard solutions ranging from two cotton balls under the pickup to checking your amp to see if a 12at7 is in the V1 position and swapping to a 12ax7 to rid the feedback.

12at7 is a lower gain tube so it's the opposite.
 

j45

Active member
Joined
Jun 14, 2002
Messages
9,081
12at7 is a lower gain tube so it's the opposite.

Ok, but you get the point. Those early 50's P-90's have always been my favorite Gibson pickups. There are lots of ways to deal with one that squels without potting. The last issue I had with this was a really good sounding PAF and guitar combination but it squealed badly when gained up. Tried several remedies and just keeping the nickel cover off seemed to solve it best. ...probably different with the plastic cover of a P-90 though
 
Y

yeti

Guest
Thanks for resurrecting this thread. I'm really on the fence on this one. Potting, if done properly can be almost transparent but I still wouldn't do it on an otherwise clean vintage guitar because unlike the other methods mentioned here it's not reversible. But since I only play cheap beater guitars I do what needs to be done. My Tele Bridge PU is lightly potted, it still squeals but with my usual amount of gain ( not very much) I can manage, plus it sounds great when you're playing right on that edge. If you can eliminate the squeal by slightly moving or a little roll off on your tone pot then I see no reason to go any further. If you play an open back amp make sure it's back isn't too close to a wall. If you're into high gain tones I'd recommend replacement PU's over potting the old ones since most high gain circuits will eliminate most of what makes microphonic PU's special anyway. Nobody can tell the difference through a Boogie,Soldano or Dumble, IMO.
 

MikeSlub

Administrator
Joined
Jul 15, 2001
Messages
15,164
The first Burst I got to play through an amp was the same way - you could talk into the bridge pickup and it came out of the amp like a voice from beyond. :)

The upside is you don't have to buy a microphone or a PA system --- finish your solo, then pick that geetar up in front of your face and sing your heart out! :2zone
 

JTinFL

Member
Joined
Jul 6, 2010
Messages
370
A few things I've learned from other occupations and hobbies over the years also apply to guitars. Always try the easy and/or cheap fix first - whatever costs you the least money or time. Then work your way up. Most problems do not require an elaborate or esoteric fix. Do one thing at a time. You'll have a definite idea of what fixed your problem. But even more importantly, sometimes you make things worse by screwing with it and you'll know exactly what you did to make it worse - so then, hopefully, you can un-do it. With old stuff, the less intrusive you can be, the less risk you have of screwing something else up. Collateral damage can really ruin your day. And old stuff becomes increasingly fragile over time, making it more susceptible to damage. Learn from other's experience - both successes and failures. Among the opinion of which approach is best in this thread, I see probably more than a dozen potential fixes to the same problem offered up. That's why I love LPF and other forums like it. Someone's always run into your problem before, and has fixed it. So I rank them by ease/cost/intrusiveness (and my ability to actually perform the fix!) and then get to work. More often than not, I find the simple stuff is usually what does the trick. Thanks for bringing this one back from the dead, Brian. I don't have any squealing P90's, but if I ever do, I now know a number of simple things to try first.
 

65Firebird

Active member
Joined
Oct 14, 2019
Messages
110
Resurrecting an old thread, my '65 Firebird neck pickup started squeeling out of control (when playing loud) a few months ago, a short time after the bridge pickup did the same. I came accross this thread and tightned the two screws on the baseplate of the pickups and put a piece of foam under each pickup then screwed them back down. Doing this fixed the neck pickup problem but didn't fix the bridge pickup, I then removed the pole piece screws from the bridge pickup put some plumbers tape around the thread and re-installed them, this didn't fix the problem.

Does anybody have any suggestions as to how to solve this problem? I don't want to pot the pickup.

Thanks in advance, Tony.
 
Top