DP123 wiring

[interp]

This is probably an obvious question to most of you, but here goes.
I just installed a pair of DiMarzio DP 123's in my Lakland JO (with concentric pots). I followed DiMarzio's instruction to the letter, but I am not sure whether I have them wired in series or parallel.
I connected pickup 1's white and black wires together, and pickup 2's white and black wires together. In other words, pickup 1's white to pickup 1's black and pickup 2's white to pickup 2's black. This was my understanding of DiMarzio's instructions, which simply say "solder the black wire and white wire together." However, when both pickups are on full the sound is a bit thin, then kicks in noticeably if I cut back the bridge pickup to about 80%. When each pickup is soloed this does not happen.
Is this just normal phase cancellation, or have I inadvertently wired these pickups in parallel?

Thanks in advance for any input from wiser heads!

 

[MIJ-VI]

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Important:

Read all of the following instructions before proceeding. If any questions or
problems arise, you may refer them directly to us.

Your new pickup is a direct replacement for the original pickups in all Jazz
Basses. (No modification to the Jazz Bass is necessary for installation.)

The installation of an optional miniature switch will provide the pickup with
series/parallel.

Phase reversal is also possible. Further information on the options is available direct from DiMarzio, Inc.

REMOVING THE ORIGINAL PICKUP

The front pickup will be called pickup one; the bridge pickup will be called pickup two.

Loosen or remove the strings. Unscrew all screws fastening the pickguard to the bass and carefully remove the pickguard.

Unscrew the screws holding down the control plate and carefully turn it over so that the controls are exposed.

Unsolder the pickup leads from the volume pots. The hot lead is connected to the #2 leg of the pot. The ground is connected to the back of the pot. Be careful not to disconnect the other ground wire from the back of volume pot #2.

Pickup one is connected to volume pot #1, pickup two to volume pot #2

Unscrew the four screws holding each pickup in place and remove the original pickups.

You are now ready to install the new pickups.

INSTALLING THE NEW PICKUPS

It will be necessary to remove the foam rubber which is attached to the plate beneath the pickups, as the new pickups are slightly deeper than the original.

Cut a smaller piece of the packing foam, about 3" x 5/8", and place it beneath each of the pickups to give them some cushioning.

Install the pickups in their respective compartments and run all four wires from each through to the control compartment.

Screw the pickup in with the original mounting screws.

WIRING THE PICKUPS

Solder the red wire of each pickup to leg #2 of its respective volume pot.

Solder the green wire of each pickup to the back of its respective volume pot.

Solder the black and white wire of each pickup together. Put a piece of tape on this connection so that it does not touch any other part of the circuit.

The wiring is now complete.

 

[interp]

Thanks MIJ-VI. These are the instructions I used. My question has to with the phrase "solder the black and white wire of each pickup together." I believe I understood that correctly, that is, black wire from pickup 1 is soldered to white wire from pickup 1.

My problem is this: When all knobs for both pickups are at full position the sound is somewhat thin. When I turn the bridge pickup volume downward it suddenly get beefier at about 80% and remains unchanged as I continue turning it down to zero. In other words, it sounds as if the bridge pickup is only working in the 80-100% range.

The converse is true: If I start with both pickups at the full position and gradually turn the neck pickup downward the tone becomes much more trebly at about 80% and then remains unchanged as I continue downward to zero. Sounds like the neck pickup is only working the 80-100% range.

This effect is only observed when the two pickups are on. When soloed each pickup produces a smooth increase/decrease in volume.

Does this have to do with phase cancellation? Pot characteristics? Series/parallel issues? Just how concentric pots behave?

I should mention that I love the sound of these pickups. I have them on a custom jazz (V/V/T) that I've been playing since 1982, but I never encountered this.

Thanks again for any ideas!

 

[PJSShearer]

Sounds to me like you have the two pups wired out of phase with each other - I use a DPDT switch on my own instrument to get this effect. You are correct about soldering the black and white wires together BTW.

Two things to check:

1. Are the Red and Green wires going to the same lugs on the Volume pots?.

2. Are both pups installed the same way round - as I recall with DiMarzio Js, two of the 4 wires come from one end of the pickup and the other two from the other. Use this to confirm that both pups are the "same way up".

 

[line6man]

Yes, the black and white wires go together.

Like PJSShearer said, it sounds like they are out of phase.

Swap the red and green wire on one of the pickups, and that should solve the problem.

 

[interp]

Thanks for the suggestions, guys.

However, I checked everything out. Red wires from each pickup going to leg #2 of their respective pots, green wires going to the back of the pot. Pickups are installed in the correct orientation.

Problem not solved.

I'm out of ideas.

 

[MIJ-VI]

Thanks for the suggestions, guys.

However, I checked everything out. Red wires from each pickup going to leg #2 of their respective pots, green wires going to the back of the pot. Pickups are installed in the correct orientation.

Problem not solved.

I'm out of ideas.

Hi interp.

Right then. DiMarzio's installation instructions are for a Fender Jazz Bass with standard 250K Ohm VOLUME + 250K Ohm VOLUME + 250K Ohm TONE pots.

Whereas: "I just installed a pair of DiMarzio DP 123's in my Lakland JO (with concentric pots). I followed DiMarzio's instruction to the letter, but I am not sure whether I have them wired in series or parallel."

I believe that on concentric pots, the pot closest to your bass' control plate will be the TONE pot (500K Ohms) and the other one will be the VOLUME pot (250K Ohms).

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"Concentric 250K/500K Audio, Solid Shaft Potentiometer (Used for the stacked Volume and Tone controls on the American Vintage '62 Jazz Bass®)"

Which pot(s) did you wire your new pickups to?

(Your bass' controls worked properly with the old pickups, yes?)

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As for your new pickup's wiring:

Your new pickups appear to be a hum-canceling, split-coil design similar to this:



Connecting the black and white wires together merely connects the two coils in series, in phase (which is correct, and what you have already done).

The red wire is the hot, the green is the ground.

Just solder these two wires to the same locations that your old pickups' hot and ground wires were soldered to.

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If doing so does not work, then could you please post some photos of the pots so we can see how things are wired?

Thank you.

 

[line6man]

Thanks for the suggestions, guys.

However, I checked everything out. Red wires from each pickup going to leg #2 of their respective pots, green wires going to the back of the pot. Pickups are installed in the correct orientation.

Problem not solved.

I'm out of ideas.

Invert the phase of one pickup by swapping the red and green wires...

 

[interp]

Thanks for your suggestions, guys.

I am putting this on hold for a couple of days, as I have ordered the parts required to convert this bass to a three-knob V/V/T configuration. I've decided that I don't like the stack knob configuration.

When I get everything installed and wired I'll report back if there are any problems.