Resistance measures fine, but very low output?

[Kramer_baretta]

Hi guys,

George here from the Kramer Guitar forum. As you may know, Kramer almost exclusively used SD pickups, and I am a big fan of the JB/Jazz combination.
Currently I am having a problem with one JB pickup: I get very little output when it's wired in, but it measures ok on my multimeter. When I measure the resistance, I get about 14.6K. (a little low for a JB / SH-4, but acceptable) However, when I wire it in, I get about half the output. The pickup is in a one-volume, one-pickup guitar (Kramer Baretta) so it's an easy installation. I have switched both the pot and the input jack to be sure. Here's the diagram I am using:

I appreciate any feedback you guys have on this!
(If you're curious, here's a link to my guitar collection--lots of Seymour Duncan pickups! )
http://www.kramerforum.com/george/kollection/

Thanks bros,
George

 

[Robert S.]

Re: Resistance measures fine, but very low output?

14.6K is quite a bit low for a JB but you should still have a pickup that delivers plenty of output and the Custom series pickups are in the 14.6k range. What you have there is more in the range of a C-5, but I believe the JB uses a thinner guage wind wire.

Another thing that can effect a pickups output is the magnets strength. You may have a bad magnet (low strength) that may have had issues during magnetization or it may have been de-guassed along its way to you. Also any source of EMF can de-guass a magnet, including using a soldering gun instead of a soldering iron. Soldering guns have transformers in them and using a soldering gun to install pickups can damage the charge of a magnet.

If you are in the U.S. and you bought the pickup new, I'd exchange it. It's too far out of spec and the lack of output is suspicious. A single volume/single pickup guitar is too easy to wire and if you've done a few successful installs you most likely have it right but checking your solder joints is always advisable.

Welcome to the SD User Group Forum George, glad to have you aboard!

Robert

 

[bryvincent]

Re: Resistance measures fine, but very low output?

the white and red wires soldered together should not be connected to ground. it sholud be insulated.

 

[Robert S.]

Re: Resistance measures fine, but very low output?

Great eye Bry......

 

[Zerberus]

Re: Resistance measures fine, but very low output?

the white and red wires soldered together should not be connected to ground. it sholud be insulated.

+1, first thing I thought when I saw the diagram....

 

[Lewguitar]

Re: Resistance measures fine, but very low output?

Yep. The way that pickup is connected you've turned it into a single coil.

Lew

 

[Kramer_baretta]

Re: Resistance measures fine, but very low output?

Great eye, thanks guys! Yes, The red and the white are taped together and not soldered to ground--I am using a diagram from VintageKramer.com -- guess I should tell them it's wrong. I am only connecting green and ground wire to ground--and black to hot.

The pickup is from 1986 or so, so I don't think there's a chance of exchanging it. I believe the theory on weak magnets applies here--when I bring a metallic object like a scissor to the p/u in question, I get very little pull. However, I thought that would affect the resistance as well? Or is the resistance only a factor of the wire here? The pickup is a reverse zebra, with a sticker that reads "JJB" on the bottom.

Thanks, fellows!

George

 

[TheGZeus]

Re: Resistance measures fine, but very low output?

Great eye, thanks guys! Yes, The red and the white are taped together and not soldered to ground--I am using a diagram from VintageKramer.com -- guess I should tell them it's wrong. I am only connecting green and ground wire to ground--and black to hot.

The pickup is from 1986 or so, so I don't think there's a chance of exchanging it. I believe the theory on weak magnets applies here--when I bring a metallic object like a scissor to the p/u in question, I get very little pull. However, I thought that would affect the resistance as well? Or is the resistance only a factor of the wire here? The pickup is a reverse zebra, with a sticker that reads "JJB" on the bottom.

Thanks, fellows!

George

you can take the magnet out and it'll read the same.

 

[Kramer_baretta]

Re: Resistance measures fine, but very low output?

Very interesting, thanks guys!
George