G&L Kiloton/BigRig Wiring Assistance

[5StringPocket]

I picked up a used Kiloton 5 with a beautiful 3-tone burst Empress body and Chechen fingerboard. Great neck and I like the solid punch of that MFD bridge pickup but thought it could benefit from the right neck pickup to provide a wider palette of tones. I've been wanting to try a Nordstrand BigRig and thought this bass would be a good candidate so I ordered one with custom spacing to fit as shown.

The G&L Kiloton wiring diagram shows passive volume/tone controls with a series/parallel/single coil pickup mode switch. What I'd like to do is replace the existing volume pot with a Noll 250K stacked volume pot, leaving the MFD circuit as-is but using the 2nd volume pot to tie in the BigRig pickup. Tone would become master tone for both pickups. The wide lower volume knob would control the MFD and the smaller top knob would control BigRig volume. The BigRig pickup will be wired in series as shown in the Nordstrand website with RED/WHT wires soldered and taped, BLK as hot, and GRN/BARE as ground.
Pickup Wiring Diagrams and Schematics
I found a local guitar tech who will route and mount the pickup and solder connections according to the wiring diagram provided but he won't develop or be responsible for accuracy of the wiring diagram. I think I'm good up to this point but tying the BigRig volume pot into the rest of the circuit is what I need help with. In the wiring diagram below I followed a standard jazz bass VVT tone circuit which connects the neck ground to pot body and upper tap, neck hot to center tap, and the attenuated output then ties to the bridge volume. The hot tap connections don't seem right when compared to the standard jazz bass wiring so I'm trying to get that sorted. Any assistance to make this diagram accurate to proceed with the project would be appreciated.

 

[5StringPocket]

I wonder if reversing the MFD hot and attenuated tap connections on the new V/V pot as shown would make these 2 pickups work properly in parallel?

 

[coronado3]

you are doing almost exacly what I want to do, except for the added pickup being another MFD. When finished, please record some video samples!

 

[5StringPocket]

Will do.

 

[ex-tension]

...What I'd like to do is... leaving the MFD circuit as-is but using the 2nd volume pot to tie in the BigRig pickup.
...
I followed a standard jazz bass VVT tone circuit which connects the neck ground to pot body and upper tap, neck hot to center tap, and the attenuated output then ties to the bridge volume.

Kiloton is a one-pickup bass so, it's wired like a P-bass. J-bass is a two-pickup bass and the wiring is different.
See the diagram below. As you see, pickup hot (white) is going to the outer lug of the VOL-pot. Then the VOL-pot wiper lug going to the output.
On the J-bass wiring diagram you attached as you can see the pickup hot goes to the wiper lug and the outer lug going to the output.

So, that is why:

The hot tap connections don't seem right when compared to the standard jazz bass wiring...

So, If you want to wire your bass like a J-bass you cant leave the MFD circuit as-is.

In your diagram, you should connect the hot wire from switch to the VOL-pot wiper. And the wire from VOL-pot to the output should connect to the outer lug of the VOL-pot (the same lug connected to the tone-pot).

 

[ex-tension]

I wonder if reversing the MFD hot and attenuated tap connections on the new V/V pot as shown would make these 2 pickups work properly in parallel?

Correct

 

[Alivefor5]

Subbed! I also have been thinking along these lines with a 4 string Kiloton. Please let us know how it sounds.

 

[Jackcrow]

I really like this idea. I wish G&L would make a 2 pickup variant of the kiloton with 2 MFD’s right next to each other.

The only thing I think I would add is maybe a push/pull pot with a DPDT switch as your tone pot to switch between series and either parallel or single coil on the big rig.

 

[GlennRH]

No need to add another pickup or two if bigger balls is your objective.

Just add a .001 uf capacitor to circuit between the pickup and the tone pot to lower the resonant frequency of the pickup. More low end all the time.

To verify this as, see Paul Gagon's posts about the Kiloton circuitry at Basses By Leo.

Otherwise, trust me, an L-1500 player for about 24 years: Your bass can deliver a plenty-wide-enough tone palette as-is. Let your new bass teach you how to find it.

 

[5StringPocket]

I really like this idea. I wish G&L would make a 2 pickup variant of the kiloton with 2 MFD’s right next to each other.

The only thing I think I would add is maybe a push/pull pot with a DPDT switch as your tone pot to switch between series and either parallel or single coil on the big rig.

Thought about that but after listening to different clips I like series best and given that the BigRig in parallel has a low output level I'd like to keep the wiring simple and straight forward.

No need to add another pickup or two if bigger balls is your objective.

Just add a .001 uf capacitor to circuit between the pickup and the tone pot to lower the resonant frequency of the pickup. More low end all the time.

To verify this as, see Paul Gagon's posts about the Kiloton circuitry at Basses By Leo.

Otherwise, trust me, an L-1500 player for about 24 years: Your bass can deliver a plenty-wide-enough tone palette as-is. Let your new bass teach you how to find it.

The BigRig is for a more diverse tone palette, plus I'm curious about this pickup and want to see what it sounds like. Part of the low end character is from the pickup but it is also influenced by pickup location. Either pickup is a different flavor of good soloed but I'd also like to see how they blend.

 

[5StringPocket]

I just got a call from the repair tech that all modifications are done and checked according to the diagram in Post#2. Everything works as it should except that the MFD volume acts like a master volume. You can blend in the BigRig but you can't turn down the MFD and solo the BigRig. I'm baffled as to why because this VVT diagram seems straight forward enough. Any insight to a fix for this would be much appreciated.

 

[Jackcrow]

I just got a call from the repair tech that all modifications are done and checked according to the diagram in Post#2. Everything works as it should except that the MFD volume acts like a master volume. You can blend in the BigRig but you can't turn down the MFD and solo the BigRig. I'm baffled as to why because this VVT diagram seems straight forward enough. Any insight to a fix for this would be much appreciated.

Sounds like it’s wired incorrectly. The tech checked it out and gave it to you like that? Seems very simple, the output from the 3 position switch goes to where the white wire from the bridge pickup would go. Then the hot lead from the big rig goes to where the white wire from the neck pickup would go. Finish the rest as per the Jazz VVT diagram.

I’m no expert though.

 

[Jackcrow]

I’m going to guess the volume pot for the MFD doesn’t have the ground connection on the one solder lug.

 

[ex-tension]

...MFD volume acts like a master volume. You can blend in the BigRig but you can't turn down the MFD and solo the BigRig.

Sounds like it's wired according to the diagram in post#1.
If you post some photos of the wiring we can try to see what's going on.

 

[grouse789]

 

[grouse789]

Thats whatcha' need to did...

 

[Crater]

Thats whatcha' need to did...

Nope. The OPs bass doesn't have a pickup selector switch.

Everything works as it should except that the MFD volume acts like a master volume. You can blend in the BigRig but you can't turn down the MFD and solo the BigRig.

That is exactly how the wiring diagram you supplied to your tech works.

If you want "blend-able" pickups like a Jazz Bass, then the connections that are circled need to be swapped...center pot terminal to the output jack tip terminal.

 

[grouse789]

Nope. The OPs bass doesn't have a pickup selector switch.

That is exactly how the wiring diagram you supplied to your tech works.


View attachment 4226080

Right, but in the spirit of the G&L design, you would add a pickup selector switch. The diagram I posted was drawn up by Paul Gagnon, as was the OP's first diagram.
The rendition I showed added the L series "spirit" with a pickup selector and bass cut.

 

[5StringPocket]

Nope. The OPs bass doesn't have a pickup selector switch.

That is exactly how the wiring diagram you supplied to your tech works.

If you want "blend-able" pickups like a Jazz Bass, then the connections that are circled need to be swapped...center pot terminal to the output jack tip terminal.
View attachment 4226080

This matches the reply I got on the G&L forum and makes sense. I'll call the tech and verify before picking up the bass. Here's what they wrote: "The only way (that I can see from looking at the diagram) for the bridge pickup volume to act as a master is if the output to the jack socket was taken from the wiper (centre lug) and the wire from the "mode switch" was connected to the "hot" end of the pot (lower lug on the diagram) along with the wire from the bridge pickup pot."

@grouse789, I want to keep the wiring as simple as possible with just a standard VVT setup using a stacked volume pot - no extra holes in the pick guard. I just want a volume for each pickup and a master tone.

 

[5StringPocket]

The wiring diagram in the previous post is correct. The tech who mounted the pickup did a great job on the body but wasn't an electronics guy. Guitar Hacienda, who I usually do business with, has a tech with good electronic skills. I showed him the wiring diagram and explained how the stacked volume should work. He found and fixed a wiring error and the controls work as they should. I've been quite pleased with this modification and really like the extra tones the Big Rig provides.