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Hi all,

I recently had my stock ceramic pickups in my Gibson Lespaul 1960 Classic (1992 Reissue) with a set of SD Alnico 2 Pro humbuckers.

They sound great. The Alnico 2 Pros have 4 conductor wiring and they were wired quot;standardquot; as stated in the documentation. The pickup installation was done by a certified technician. I've opened up the guitar and the wiring seems fine.

When I am playing on only the Neck pickup or only the Bridge pickup, I can hear a slight humming sound, much like a single coil would do. When my pickup selector is in the middle position (when both pickups are used at the same time), the hummig stops, probably because they cancel each other out.

I don't think this is normal. Humbuckers are not supposed to hum, thus the name!!!

The wiring was not done to split the coils at all.

The humming is not overbearing and it's not heard when I play but it is present when I'm not playing.

What do you guys think?

Thanks!!!

For what it's worth, some of the Alnico 2 humbuckers seem to have more hum than Ceramics (and Alnico 5?). My Custom Custom hummed, and it was wired correctly. The consensus is that it has something to do with the metallic properites of the magnet picking up radio frequencies.

are you standing near a flourescent light or computer monitor when it is happening? it could be RF interference, not 60 Hz hum .... how well is the guitar shielded / grounded?

Hey ZOSO, you might want to get a screw driver and tap on each pole set. By this I mean put the selector on neck and tap on a screw side then the slug side. After that put it on the bridge selection and repeat the process. Then try it in the both position. The reason I say this is that it sounds like you might have coils that are not always quot;onquot;. Another thing is the pup might even have an internal wiring problem, for instance the green might be soldered to to the wrong place so you might have you pups operating in paralle, shoot the tech might have accidental even done it.......but you said everything LOOKS alright. Soooooo, let's try the experiment first.

Luke


Originally Posted by Luke DukeHey ZOSO, you might want to get a screw driver and tap on each pole set. By this I mean put the selector on neck and tap on a screw side then the slug side. After that put it on the bridge selection and repeat the process. Then try it in the both position. The reason I say this is that it sounds like you might have coils that are not always quot;onquot;. Another thing is the pup might even have an internal wiring problem, for instance the green might be soldered to to the wrong place so you might have you pups operating in paralle, shoot the tech might have accidental even done it.......but you said everything LOOKS alright. Soooooo, let's try the experiment first.

Luke

I agree... If both pickup were picking some hum cause is they way they quot;behave normalyquot;, then the noise should double in the middle position, not cancel. That screw experiment is very simple and useful, It will tell exactly which coils are working on every selection...

I've used many different alnico 2 pickups, and none of them have ever hummed...not even a tiny bit. It sounds like he screwed up the wiring somewhere, especially if it cancels in the middle position.

Ryan


Originally Posted by rspst14I've used many different alnico 2 pickups, and none of them have ever hummed...not even a tiny bit. It sounds like he screwed up the wiring somewhere, especially if it cancels in the middle position.

Ryan

So what I am gathering from all of this is that they are NOt supposed to hum. I kind of figured since they are called humBUCKERS. lol

I have checked the wiring and it is done exactly the way it is written in the documenation that came with the pickups. I also confirmed the wiring schematics on this forum with quite a few people.

The tech has an oustanding reputation and has been guitar repairs for years. I would be shocked and pissed if he screwed up the wiring. These pickups have 4 wires. My previous thread concerning this wiring is here:

from : localhost//forum/s...ad.php?t=31409

Since the red and white wires are responsible for the coils, they must be causing the humming.

By the way, the humming is exactly as if I had some single coils in there (but the pickups sound like humbuckers when I play).


Originally Posted by Luke DukeHey ZOSO, you might want to get a screw driver and tap on each pole set. By this I mean put the selector on neck and tap on a screw side then the slug side. After that put it on the bridge selection and repeat the process. Then try it in the both position. The reason I say this is that it sounds like you might have coils that are not always quot;onquot;. Another thing is the pup might even have an internal wiring problem, for instance the green might be soldered to to the wrong place so you might have you pups operating in paralle, shoot the tech might have accidental even done it.......but you said everything LOOKS alright. Soooooo, let's try the experiment first.

Luke

Hey Luke,

Thanks for the little test. Should I hear some tapping on both coils?

Thanks,

OK. a couple of things I saw from that other thread:

quot;The red and white cable are to be taped together and soldered on the pot. I'm not sure exactly where though. Anywhere on the flat part of the pot?quot;

If you did this then that would explain the humming. This would split the coils. For humbucker operation you do not ground anything except the shield and the green (standard wiring).

quot;For the red and white cable, I will strip the outside coating of both wires, tie both cables together and tape them up? I don't have to solder both of those wires anywhere?quot;

It is far more reliable to solder these wires together. If they are only taped and are not making good contact then again, you only have one coil working which would explain the humming.

You said that you had someone else install the pickups. In that case, I would go back to them and tell them about the problem. Should be pretty easy to work out.

P.S. When you tap on each coil you should hear a sound come out of the amp. It should be roughly equal volume for each coil. If you have no sound on one or more coils then something is wired wrong or the pickup is damaged.


Originally Posted by frankencatOK. a couple of things I saw from that other thread:

quot;The red and white cable are to be taped together and soldered on the pot. I'm not sure exactly where though. Anywhere on the flat part of the pot?quot;

If you did this then that would explain the humming. This would split the coils. For humbucker operation you do not ground anything except the shield and the green (standard wiring).

quot;For the red and white cable, I will strip the outside coating of both wires, tie both cables together and tape them up? I don't have to solder both of those wires anywhere?quot;

It is far more reliable to solder these wires together. If they are only taped and are not making good contact then again, you only have one coil working which would explain the humming.

You said that you had someone else install the pickups. In that case, I would go back to them and tell them about the problem. Should be pretty easy to work out.

P.S. When you tap on each coil you should hear a sound come out of the amp. It should be roughly equal volume for each coil. If you have no sound on one or more coils then something is wired wrong or the pickup is damaged.What he said... If you have the R/W soldered to the back of a pot you are grounding out one coil and running in single coil mode.

Plus, the hum is not necessarily coming from the pups. There is a lot of other circuitry that can be picking up noise.

The red and white wire's should be soldered together and taped off, not soldered to the pot. That may be the issue. The other issue could be a grounding problem. I have several APH's, and none of them hum.


Originally Posted by frankencatOK. a couple of things I saw from that other thread:

quot;The red and white cable are to be taped together and soldered on the pot. I'm not sure exactly where though. Anywhere on the flat part of the pot?quot;

If you did this then that would explain the humming. This would split the coils. For humbucker operation you do not ground anything except the shield and the green (standard wiring).

quot;For the red and white cable, I will strip the outside coating of both wires, tie both cables together and tape them up? I don't have to solder both of those wires anywhere?quot;

It is far more reliable to solder these wires together. If they are only taped and are not making good contact then again, you only have one coil working which would explain the humming.

You said that you had someone else install the pickups. In that case, I would go back to them and tell them about the problem. Should be pretty easy to work out.

P.S. When you tap on each coil you should hear a sound come out of the amp. It should be roughly equal volume for each coil. If you have no sound on one or more coils then something is wired wrong or the pickup is damaged.Hey Frankencat,

Yeah, forget about the quot;soldering the R/W cables to the potquot; thing. I was mixed up back then.

I checked again yesterday and the R/W cables are soldered together and taped up. The guitar tech did it right, as the instructions that came with the pickups said.

I also did the test by tapping on both coils of both pickups. For each pickup, you could hear the tapping through the amp at pretty much the same volume. So, it seems to me that both coils are working on both pickups. I assumed that would be the case because the pickups do sound like humbuckers when I play, not single coils.

I tried playing the guitar in many rooms (different settings) through various amps and there is always a little humming (especially on the dirty channels when using my Marshall TSL100) except when the pickup selector is in the middle position (both pikcups on). I have played other LesPauls with the same amp, the same settings in the same rooms and have never had a humming problem.

I'll take it back to the tech to see if he can figure something out.

Thanks for your help!!!


Originally Posted by Jeff_HThe red and white wire's should be soldered together and taped off, not soldered to the pot. That may be the issue. The other issue could be a grounding problem. I have several APH's, and none of them hum.

Hey Jeff_H,

The ground cable is the green one and I know it should be soldered to the pot. Should the green cable be stripped and then the stripped part should be soldered to the pot? Soldering the green cable without stripping it won't do a thing since the coating of the cable will prevent any electrical contact?
Am I right?

I can't believe what a newbie question that is but I'm so ticked off at that humming that I'll do anything to fix it.

Thanks!!!

Is the bare ground soldered to the pot as well? If it's not then that might be the problem. The Tech Might not have got that one out, they have a bad habit of hanging onto the shielding.

Luke


Originally Posted by Luke DukeIs the bare ground soldered to the pot as well? If it's not then that might be the problem. The Tech Might not have got that one out, they have a bad habit of hanging onto the shielding.

Luke

Hey Luke,

Thanks for the reply...I'll check that as soon as I get home tonight!

You guys are all great: thanks for not making me feel like a moron for being a newbie!

Cheers,

Z0S0


Originally Posted by Z0S0You guys are all great: thanks for not making me feel like a moron for being a newbie!

That's the great thing about this place - you don't have to be a newbie to be a moron. Some of us have been here years.