Pickup has less output?

[dvanburen]

I have a duncan custom that I pulled out of one guitar and put into my les paul. I have noticed that after playing with it for a bid on the LP that is has less output than when it was in my other guitar. I have tried adjusting the height on the pickup and that does not really work. Also, the pickup feeds back easier. Does it need to be re-potted? Is this a wiring issue? or am i just losing it.. All the wiring should be correct.

 

[jeremy]

Re: Pickup has less output?

some guitars are louder than others and react differently

swapping pups shouldnt make it need to be repotted. cant hurt to recheck your wiring

 

[LtKojak]

Re: Pickup has less output?

I have a duncan custom that I pulled out of one guitar and put into my les paul. I have noticed that after playing with it for a bid on the LP that is has less output than when it was in my other guitar. I have tried adjusting the height on the pickup and that does not really work. Also, the pickup feeds back easier. Does it need to be re-potted? Is this a wiring issue? or am i just losing it.. All the wiring should be correct.

Sounds like either a cold solder joint somewhere or faulty connection in the series joint to me.

Recheck the wiring with a MM.

 

[totergecko]

Re: Pickup has less output?

your les paul probably has a 300k volume pot. I'm betting your other guitar has a 500k volume pot, since that's sort of the industry standard for humbucking pickups. if you want to get some more output you could try switching the volume pot out on your les paul to a 500k instead, see if you like it.

 

[octavedoctor]

Re: Pickup has less output?

your les paul probably has a 300k volume pot. I'm betting your other guitar has a 500k volume pot, since that's sort of the industry standard for humbucking pickups. if you want to get some more output you could try switching the volume pot out on your les paul to a 500k instead, see if you like it.

A 300K pot won't pull down the volume that much; the RMS voltage across the input tag and earth will still be the same but the taper may change and the resonant peak will be different. It's a misconception that a 300k pot acts like a 500k turned down by 40%; it doesn't, because it's a potential divider so there would have to be a 200k fixed resistance between the signal path and the input tag for that.

I'd be more inclined to go with the dry joint theory and I'd recommend taking a resistance reading across the guitar output with the volume on full and only the Duncan custom switched on. you should get a DC resistance reading of around 13.7KΩ if the spec is to be believed. If it's more than this then you have a bad joint in the circuit or a problem with the pickup. Disconnect the pickup and your reading across the signal and trailing/earth wire (that should be black and green in stock config, red and white in reverse config) should be around 14kΩ.

Another thing to consider is that the bridge pickup on a Gibson can sit slightly closer to the bridge than on other guitars and there is less displacement of the string in the pickup's magnetic footprint. A friend recently put a Duncan Custom in an SG and was so disappointed in the output he had me check all his wiring, but there was nothing wrong with it.

 

[octavedoctor]

Re: Pickup has less output?

Does it need to be re-potted?

Wax potting is a fix for microphony; it doesn't make the pickup any louder or more powerful, it just seems that way because you can drive the amp harder without squealing feedback. Bad or broken coil connections are the prime candidate. A break deep inside the coil doesn't cause the pickup to go dead; it just goes quiet and trebly because the two parts of the coil couple inductively and the coil starts behaving like a capacitor: the signal can "jump the gap", blocking low frequencies but allowing high frequencies through.

 

[GuitarDoc]

Re: Pickup has less output?

Make sure all your solder joints are good (solder is thin and flows like water). Otherwise you may have a cold/dry connection.

 

[dvanburen]

Re: Pickup has less output?

the reason I asked about repotting the pickup is because it feeds back easily and the pickup is several years old and about a year ago had a nickel cover put on it. never had any issue until I swapped the pickup and put it into my les paul. I dont hear any other funny stuff coming from it. What exactly is a cold solder joint? Too much, too little solder? not clean?

 

[octavedoctor]

Re: Pickup has less output?

the reason I asked about repotting the pickup is because it feeds back easily and the pickup is several years old and about a year ago had a nickel cover put on it.

It's possible to get squeal as a result of micro changes in the capacitance created by the cover. This is distinct from harmonic feedback which is desirable as long is it can be controlled because that's how you produce sustain.

never had any issue until I swapped the pickup and put it into my les paul. I dont hear any other funny stuff coming from it.

Shouldn't really be a problem then, but only a meter test will establish with any certainty

What exactly is a cold solder joint? Too much, too little solder? not clean?

To produce a good electrical connection the solder has to alloy itself with the surface of the metal being soldered (the substrate). To do this, it has to reach a certain temperature. A dry, or "cold" soldered joint hasn't undergone this process and although it appears to be complete, the electrical conductivity is poor.

The trick, when soldering, is to "tin" both components of the joint so that they have a coating of solder which has alloyed to the surface. To this end electrical solder uses "flux" which melts at a lower point than the solder. Because metal oxidises when heated the purpose of the flux is to coat the substrate and prevent oxidisation. When the solder melts the flux floats above it (because it is less dense) and allows the solder to fuse with the substrate.

When the joint is brought together all that is required is enough heat to melt the solder on both parts of the joint which will flow together, effectively welding the joint and producing good electrical conductivity.

 

[dvanburen]

Re: Pickup has less output?

Thanks everyone for the replies. I actually just went ahead And pulled Apart the pickup. One thing I found was that the last guy that worked on it left some space between the pickup and the nickel cover. The other thing...was that I found that about 1/8 of the magnet was broke off!!! I pulled it out and it was just broke right off of the magnet. I dont think that i broke it while changing the magnet. I think it was like that( don't know how). I'm sure this was part or all of the problem. I replaced the magnet and got everything secured back in place and it all works just fine. Thanks to all that helped me diagnose this. Cheers.

 

[GuitarDoc]

Re: Pickup has less output?

To produce a good electrical connection the solder has to alloy itself with the surface of the metal being soldered (the substrate). To do this, it has to reach a certain temperature. A dry, or "cold" soldered joint hasn't undergone this process and although it appears to be complete, the electrical conductivity is poor.

The trick, when soldering, is to "tin" both components of the joint so that they have a coating of solder which has alloyed to the surface. To this end electrical solder uses "flux" which melts at a lower point than the solder. Because metal oxidises when heated the purpose of the flux is to coat the substrate and prevent oxidisation. When the solder melts the flux floats above it (because it is less dense) and allows the solder to fuse with the substrate.

When the joint is brought together all that is required is enough heat to melt the solder on both parts of the joint which will flow together, effectively welding the joint and producing good electrical conductivity.

Good explanation. I might just add that the rosin in rosin core solder acts as the flux. (It is not always successful and sometimes an additional paste flux can be helpful). However, the real key ingredient is heat. Enough heat applied to the clean substrate to allow the solder to flow onto the substrate, not just accumulate/glob up there. "Meat follows heat".