Fender Jaguar volume and tone pot wiring

[Deaf Eddie]

I had a request for someone who wanted to modify a Jaguar-type setup. OK, I love a good puzzle.

Working from the Seymour Duncan drawing of the wiring, it shows something I've NEVER seen before: the output from the pickup(s) FIRST goes to the THIRD LUG of the tone pot, then back from the middle lug of the tone pot to the volume pot. I've never seen a scheme that used the third lug of the tone pot for anything!

I realize that this diagram shows their stacked humbuckers, but still...
Is this how Fender wires the Jaguar?
Anybody have an idea what's up with this wiring idea?
Inquiring minds want to know...

BTW, along with the other mods he requested, I redrew the lower vol and tone connected the "normal" way, but left the upper volume and tone as drawn here. Can't wait to hear his results.

 

[Deaf Eddie]

Digging around to see if I could find another example of this odd wiring, I came across this drawing of a Guild T-Bird, which practically duplicates the Jaguar scheme!

 

[AAT65]

Yes, more or less — this is how the American Vintage Jaguar is wired:

https://www.fmicassets.com/Damroot/Original/10002/011-2100A_SISD.pdf

(It’s always worth looking on fmicassets.com for wiring diagrams — technical manuals for most of their recent MIA and MIM guitars are there.)

The Fender wiring has a small (56k) resistor which effectively bridges the tone pot and the Guild wiring uses 68k: I think the SD diagram should have a resistor like this too.

I think the circuit is wired this way so that there is smallish load for the bass-cut capacitor to work against (very hand-waving explanation ).

 

[Deaf Eddie]

Yeah, I see the resistor you mention, but the bass-cut doesn't function in the "rhythm" setting - yet the tone and volume for that circuit are ALSO wired that way. Wish I had one here to see what that does to the sound (if anything audible). It must do SOMETHING, or else why wire it like that? Maybe I'll rewire the tone and volume on a Tele that way just to check it out.

I wonder if this is another of Leo's "innovations" that didn't catch on as a general guitar wiring practice.

 

[AAT65]

I had to sketch this up as a schematic to try to get to grips with it…

I don’t think it made things exactly crystal clear! However I see now that the big difference between this and the “normal” tone wiring is that as you turn the tone control down then you end up feeding the signal through the 56k resistor (in parallel with an increasing amount of the tone pot) on the way to the volume control. That will drop the volume slightly - about 1.8dB - as you turn the volume down. Not sure if that is what Leo was going for..!

(BTW the rhythm circuit as you correctly point out also has this odd wiring - there’s no 56k resistor in that case, because the tone pot is only 50k. And that made me look up how a Jazzmaster is wired: it has the “normal” volume / tone wiring on the Lead circuit, but the Rhythm circuit has the same wiring as the Jaguar. I will try to remember to play with this next time I’ve got my JM plugged in…)

 

[cyberpunk409]

I had to sketch this up as a schematic to try to get to grips with it…
View attachment 1215543
I don’t think it made things exactly crystal clear! However I see now that the big difference between this and the “normal” tone wiring is that as you turn the tone control down then you end up feeding the signal through the 56k resistor (in parallel with an increasing amount of the tone pot) on the way to the volume control. That will drop the volume slightly - about 1.8dB - as you turn the volume down. Not sure if that is what Leo was going for..!

(BTW the rhythm circuit as you correctly point out also has this odd wiring - there’s no 56k resistor in that case, because the tone pot is only 50k. And that made me look up how a Jazzmaster is wired: it has the “normal” volume / tone wiring on the Lead circuit, but the Rhythm circuit has the same wiring as the Jaguar. I will try to remember to play with this next time I’ve got my JM plugged in…)

You said, "That will drop the volume slightly - about 1.8dB - as you turn the volume down."

Did you mean to say, "That will drop the volume slightly - about 1.8dB - as you turn the *TONE* down."

I'm trying to trouble shoot my Jaguar. What would happen if instead of a 56k resistor, there was a 470k resistor?

My tone knob is acting like a volume knob pretty much. Here's a close up of the resistor in my jaguar, I know it's not 56k, not sure the exact value:

 

[AAT65]

You said, "That will drop the volume slightly - about 1.8dB - as you turn the volume down."

Did you mean to say, "That will drop the volume slightly - about 1.8dB - as you turn the *TONE* down."

I'm trying to trouble shoot my Jaguar. What would happen if instead of a 56k resistor, there was a 470k resistor?

My tone knob is acting like a volume knob pretty much. Here's a close up of the resistor in my jaguar, I know it's not 56k, not sure the exact value:
View attachment 1343503

Yes I mis-typed - there will be a small volume drop as you turn the tone down.
Your resistor looks to be 470k (yellow-purple-yellow means 474 which is 47 x 10,000 = 470,000. There might be a fourth tolerance band which I can’t see). That gives a significantly larger additional resistance in the path when you turn the tone down and will attenuate more: you’ll get an equivalent resistance of about 160k and a volume drop of about 8dB, I think.

 

[cyberpunk409]

Yes I mis-typed - there will be a small volume drop as you turn the tone down.
Your resistor looks to be 470k (yellow-purple-yellow means 474 which is 47 x 10,000 = 470,000. There might be a fourth tolerance band which I can’t see). That gives a significantly larger additional resistance in the path when you turn the tone down and will attenuate more: you’ll get an equivalent resistance of about 160k and a volume drop of about 8dB, I think.

The fourth band is gold, just the tolerance percentage

Thank you for your help! I don't know why a 470k ohm resistor was soldered there?!? Apparently it was supplied with this kit: ToneShaper Wiring Kit

And the description states it comes with:

• (1) Resistor, 56k

My tech just assumed they had supplied all the correct parts and didn't test each individual component.

Your calculated volume drop of 8dB is pretty close, I measured it with my sound meter yesterday and was getting about a 10dB volume drop, which is significant!!

At least I've solved the problem and can go about remedying it now, Cheers

 

[cyberpunk409]

Swapped the 470k resistor with a 56k resistor, all good now!

Thank you AAT65 for your help.

 

[AAT65]

Swapped the 470k resistor with a 56k resistor, all good now!

Thank you AAT65 for your help.

Good to hear that your problem is resolved and my engineering approximations turned out to be reasonably accurate!