3 pickup Jazzmaster?

[PitchShifter]

I've looked over a lot of wiring diagrams to get an idea how what i want to do can be done, but as a wiring neophyte, so far I'm none the wiser.

I'm looking at a Jazzmaster build, but want to add a third pickup in the middle position.  I want to convert the Rhythm circuit to a separate circuit giving the middle pickup it's own volume and tone controls. The neck and bridge will go through the standard circuit, though i'd like to add a blend pot in there as well.

I want both the middle circuit and B/N circuit to utlise the standard Jazzmaster switches so both circuits have an on/off capability. How to do this? Do both separate circuits connect to the input jack, or can I use one of the existing switches to select either or both circuits?

**Disclaimer: I won't be doing the actual wiring myself, just need to create the schematic**

 

[PitchShifter]

Here's a dodgy picture of what I'm trying to achieve.  i don't know how to marry the two circuits together.  Please ignore my connections to the actual lugs, I just need the architecture.

 

[Octavian B]

The upper bout switch on a jazzmaster switches between circuits (2 way), and the lower bout between pickups (3 way). I don't know much about circuit blending so probably someone else on the board is much better suited to answer this than me, but it seems like a first step will be turning the 2 way upper bout switch to a three way - lead, rhythm, or both.

 

[tfarny]

I'll offer a piece of the puzzle - run a wire from your middle pup switch to the output lug of your main pickup selector switch. Octavian, what would 'lead, rhythm, both' do in that diagram? The switch only has one function in his setup, which is to turn on the middle pup independently of the bridge and neck.
The main thing is just to follow the flow of current from each pickup to the output jack and make sure the grounding is done properly.
It would be helpful if you do a draft of your wiring diagram with the right lugs selected and the grounding done, then we could more easily help out.

 

[OzziePete]

I'll offer a piece of the puzzle - run a wire from your middle pup switch to the output lug of your main pickup selector switch. Octavian, what would 'lead, rhythm, both' do in that diagram? The switch only has one function in his setup, which is to turn on the middle pup independently of the bridge and neck.
The main thing is just to follow the flow of current from each pickup to the output jack and make sure the grounding is done properly.
It would be helpful if you do a draft of your wiring diagram with the right lugs selected and the grounding done, then we could more easily help out.

Using one of those Toggle switches that Gibson use for their 3 pickup LP Customs, you could hook up the middle pickup like Gibson do, to the Toggle.

But, without having gone to pen & paper to check if this is so, I'd suspect then you'd have to switch 2 swtiches just to get the middle pickup operational (toggle) and the vol. and tone pots operational for the middle pickup (slide switch). Which, if so, would be a bit fiddly.


Using a blend pot might mean you may not need to use a slide switch to engage the middle pickup vol. and tone pots? Maybe?

 

[tfarny]

Woah, time for a restart on this thread. Looking at your diagram and the advice so far, let me just say you need to start from scratch. It's not that complicated if you take time to understand how/why it works, instead of just following a diagram. But here's how to get what you want.

Step 1: Wire up the neck and middle pups like this, totally ignoring everything to do with the middle pup:
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=2singlecoils1vol1tone1switc

Step 2: make sure it all works and the grounding is done right.

Step 3: Wire up the middle pickup like the picture, running the 'hot' through your two-way switch and THEN to the output of your main pickup selector, on the same lug that goes to the output jack.

This'll give you: neck only, neck / mid, all three, mid / bridge, bridge only, with a separate volume and tone for the middle.

 

[PitchShifter]

I think you're right in that I need to take a step back and start from scratch again.  I need to better define exactly what I'm trying to accomplish.  As I see it, I might be trying to replicate the Jaguar wiring on a Jazzmaster, so I'll sit down and do some drawing!

 

[Octavian B]

Tfarny - sorry you're right! I didn't realize that the usual pickup switch was modified as well - sorry PitchShifter, I should've been more attentive.

What I was thinking is that if you take the original Jazzmaster schematics, make the proper modifications so only the middle pickup is connected to the upper circuit and then change the upper bout switch from a two way to a three way. The original two way switch selects between the two circuits, which is all good and well as it will select between the middle pup circuit and the other two on the schematic. Now, my thought was that by adding a third position, you can select between the lead circuit (neck+bridge), the middle pup circuit alone and both together. Now, if he leaves the other switch to the regular three way, he'll be able to select with it between bridge, neck or both. So this way he'll have a very versatile configuration, where he can select between the usual bridge neck combinations with or without the middle pickup, and just the middle pickup itself. Shouldn't this work?