Polarity of neck and bridge pre cbs Jag pickup

[Guitarman555]

Need help with polarity..
I have installed a jag 63 staggered black bottom pickup into my 64 jag(to replace incorrect reissue pickups before), searching for the second real vintage pickup to buy and place into the bridge position.
Is polariry really necessary to know? If polariry of bridge will be same as of my neck pick up, is it really a problem...? hum will be bigger or just the same as in single position? I understand that there will be no cancellation hum effect but it shoud be still fine?
Simplified question: can i buy any pre cbs jag pickup and will it work with my actual neck pickup together?

 

[jeremy]

yes, any pup will work, you just may not get humcancelling. if for some reason they are wound opposite, they would be out of phase, but you could flip the wires to get them back in phase which is easy enough.

 

[Guitarman555]

Hey Jeremy, thanks for answer. You mean flipping leads from the pickup or perhaps you mean flipping the wires in between the pickups? Cheers

 

[Mincer]

Flipping the leads from the pickups (hot becomes ground, etc).

 

[freefrog]

If polariry of bridge will be same as of my neck pick up, is it really a problem...? hum will be bigger or just the same as in single position? I understand that there will be no cancellation hum effect but it shoud be still fine?

Hum won't be bigger with non-noise cancelling pickups wired as usual, IOW in parallel (in series, it would be different). You might notice a wee bit more HF noise in some situations / with some pedal(board)s but the signal to noise ratio should be fine in most cases...

 

[Guitarman555]

So I have finally installed two pre cbs jag paired (from same guitar) staggered pickups, never touched fully original. They sound great. But, there is no hum cancelling. there is very slight add up on hum (barely noticable) when both pickups are on in the middle position. Magneticaly they are well paired (one north up, the other south up). Where is the issue if it is from the same jag? Many years ago I had similar problem on jazzmaster and I just connected cave shielding with wire leading under bridge saddle thimbles and it helped. Not sure if this could be the case.

 

[freefrog]

So I have finally installed two pre cbs jag paired (from same guitar) staggered pickups, never touched fully original. They sound great. But, there is no hum cancelling. there is very slight add up on hum (barely noticable) when both pickups are on in the middle position. Magneticaly they are well paired (one north up, the other south up). Where is the issue if it is from the same jag? Many years ago I had similar problem on jazzmaster and I just connected cave shielding with wire leading under bridge saddle thimbles and it helped. Not sure if this could be the case.

Well, if they have opposite polarities and sound in phase in middle position, their coils are also "reverse wound" relatively to each other, necessarily. IOW: they are "RWRP" and should cancel the hum... So, as a matter of fact, the noise seems to come from something else.

Sure, connecting the shielding of the electronic cavity to the grounded bridge shouldn't harm.

But beside that : are the "shielding claws" of your pickups grounded?

https://www.offsetguitars.com/forums/viewtopic.php?t=108020

 

[Guitarman555]

The pickups are untouched it even had the original black rubber gum that I didn´t remove, so I didn´t see under that. Pickups are very very probably without any touch, so there should be that wire to the claws.

 

[freefrog]

The pickups are untouched it even had the original black rubber gum that I didn´t remove, so I didn´t see under that. Pickups are very very probably without any touch, so there should be that wire to the claws.

Well, it must be due to the architecture of Jag pickups, so. Being around single coils without totally shielding them, the claws appear to me as able to act inherently like antennas, grounded or not.

I don't remember to have experimental data about that in my archives. If I find something, I'll share it.

 

[Guitarman555]

I have found another unsusual thing, with the neck pre-cbs pickup. Works great, no feedback, etc. Only thing is that by tapping the pickup there is a noise typical for microphonic pickup. Is it an issue or a beginning of problem or is it perfectly fine? Maybe some of you have the same thing with your jag staggered pickup?

 

[Mincer]

I had played a few early 60s (and late 50s) Strats, and all of the pickups were microphonic to some degree.

 

[jeremy]

many of my pups exhibit that behavior, i wouldnt worry about it

 

[Teleplayer]

Do you have pics of these items you bought? If you have a pic of uninstalled pickup, it shows the winding connections, ie. which side of the coil is grounded. There are only 2 possibilities for the coil connection..

 

[Guitarman555]

Will send the pics later, but the grounding of coil is factory to the metal dents (those are pre cbs old pu) so i cannot and don't want to switch it.

And last thing to mention is that middle(both pickups position) is bit weaker, i mean even weaker on volume than is usual for vintage jags. It plays really nicely but also bit thinner than i would expect. I don't know, if the mid position could be wired incorrectly out of phase, but i doubt it because i am sure that both pickups separately are wired correctly in phase. It's obvious by great, thick and full pleasant sound of them if in their single position. Note: I soledered pickups at the same place as the previous ones were(unfortunately i don't remember the sound of mid position before)​

 

[freefrog]

middle(both pickups position) is bit weaker, i mean even weaker on volume than is usual for vintage jags. It plays really nicely but also bit thinner than i would expect. I don't know, if the mid position could be wired incorrectly out of phase

It's normal for two pickups in parallel to be weaker than each single pickup. How weaker depends on the resonant frequencies of pickups alone VS in parallel. These resonant frequencies depend themselves on the inductance of the coils meeting the capacitance of coils & wiring...

Regarding OOP: the related tone is usually easy to recognize but If you're not sure and want to know if your pickups are in phase: record each pickup played alone direct to the board, under Audacity or something like that. Zoom to death on the beginning of each track. If one pickup has its initial attack going up while the other one has its first attack going down, they are out of phase...

 

[Guitarman555]

I did screwdriver test (in safe resistance regime) and it shows that pickups are opposite electric phase. So that´s why the sound of mid position is bit tinier and volume of mid position bit lower than I would expect. I don´t think I can do something with that (don´t want to touch the pickups themselfs, would be prolly risky) and don´t care, because actually I am starting to like the difference in sound it makes and can work with that in some songs. Some guitarplayers even search for this country like chicken sound. Actually, it is weird because I bought the pickups as a pair form an pre-cbs jag and they really have totally same patina and everything, never touched (rubber gums from the original guitar still sticked on thier bottom). Did it happen that Fender delivered guitars with opposit electromagnetic phase in first half of 60s?

 

[Guitarman555]

Summary:
magneticaly pickups are well paired (neck south up, bridge north up)
electricaly pickups are each one different phase direction: It means that by screwdriver test (resistance mode) one pickup showed when screw driver attached higher resistance and after I pulled off the screwdriver away resistence jumped down. The other pickup behaved opposite.

Maybe I just flipped hot lead with ground. It seemed to me unprobable, beause the single position of both pickups plays great.
If I don´t want to go inside the guitar and unscrew the pickups and just incidentally unsolder and solder, I have found following solution, but would like to double check with you if it is not dangerous for pickups and really works?

Multimeter setup

Set the multimeter to AC voltage mode, low range (2 V AC is fine).
Probes:
Black probe → ground (sleeve) of the output jack.
Red probe → tip (hot) of the output jack.

Test procedure:
Keep guitar plugged out.
Lightly tap the pickup pole pieces with a screwdriver.
Look at the multimeter reading:
Voltage spikes appear on red probe → hot lead is correctly soldered.
Voltage spikes appear reversed (black probe reads positive) → leads are swapped.​

 

[jeremy]

if your pups are out of phase. individually, they will sound the same, but its when they are combined that you get the weirdness. some people like it, most dont. if you flip the hot and ground wires on one pup, they will be in phase.

 

[Guitarman555]

And here are the pics - Jumper & claws grounding:.
NECK pickup: jumper is on the wrong side (lead side) of my neck 63 pickup - black wire is lead connected to rythm switch (recognised by sound which is full and perfect in single position).
BRIDGE pickup: And bridge pickup red lead (connected to pickups switch) is not connected to the claws by jumper which is correct. Unfortunately I have just pics that doesn´t show the bridge pickup clearly but I think it is recognisable (pic 1 and pic 4). I think that the phase test I described in my last post could also help...? Bridge pickup also plays perfectly in single position.
SUMMARY OF HOW IT BEHAVE SOUNDWISE: both single positions play great and just mid position has that weak sound on volume and chicken type and ads on hum a bit instead of clearing the hum.
MAGNETIC PHASE PERFECT PAIR (neck south up, bridge north up)
ELECTRIC PHASE - OPPOSITE, which is not what we need




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[freefrog]

magneticaly pickups are well paired (neck south up, bridge north up)

I had forgotten this detail. It makes wrong the advice in my previous post...

If two pickups are out of phase magnetically AND electrically, they are RWRP and sound IN phase.

To illustrate that, I'll evoke a short-scale Strat that I've here and whose bridge pickup is connected to a phase switch. Magnetically, this bridge pickup is "North up". The mid pickup is "South up". When I enable the phase switch, both pickups sound OUT of phase while they are electrically... IN phase. Conversely, they sound IN phase when they are electrically OUT of phase. Reason in both cases: their opposite magnetic polarities.

Impulse responses below (done with an ultra low impedance air coil as an electrical exciter). When both pickups sound IN phase, the attack of one pickup goes UP in the same time than the attack of the other pickup goes DOWN (bottom pic, blue and red lines). And they are hum cancelling in this case. When the first transient of both pickups goes UP, they sound out of phase and don't cancel the noise no more (upper pic).

Testing the two coils of a normally wired humbucker would give exactly the same thing than in bottom pic, FWIW.

[Post edited to be clearer, if possible...]






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