PJ pickup query

[Hit&Run]

Like it says in the title, what happens to the hum from a J pickup when it's used with a P pickup?
Does the P make the hum go away, unless the J is solo'd?

Your thoughts please, ladies & gentlemen.

[neilb]

Yes, thats my understanding.When both pups are on, they act as a "humbucking" pair.

[The Burpster]

^ Spot on!

[David Nimrod]

[quote name='The Burpster' post='143361' date='Feb 19 2008, 08:42 PM']^ Spot on![/quote]


But surely the two parts of the P pickup act as a humbucking pair...

The Jazz is a single coil on its own, so you have a Humbucker (the P) and a single coil (the J).

Does a humbucker cancel hum from a single coil, or does it need another single coil?

[Mr. Foxen]

There'd have to be cunningness to make them both not hum. Pretty sure the J hummed on my sucky p/j. The P did also, but less.

[BassBod]

Yes, the J will hum if its a single coil, but you can get humbuckings designs in the same sized case.

A P on its own is humcancelling, and a matched J pair will be hum cancelling when both on full - but back off the volume of either and it will hum like a bugger. Leo never designed the P and J to go together, so you'll find it hard to get a "matched" output from a PJ combo. Most makers just bung their existing P with their existing bridge J, so you may need to adjust the relative heights of each to get a more even output.

BB

[Hit&Run]

...aahh, as I suspected.
So, the bottom line with passive J pickups is: they'll hum unless there's a matched pair of them on full volume?
Looks like I'll be checking out full humbucking PJ sets then.

[Lfalex v1.1]

The PJ, whilst a useful combination, can hum. How much is determined by the relative levels of each pick-up as determined by the volume controls.
The exception to this is if the J is a "stacked" or "side-by-side" design, which actually makes it a closet humbucker anyway! (Then there's the Twin J from the Deluxe P, but that's a different design again!)

I've always felt that the single coil aspect suffers relative to the split "P", which is possessed of a higher output, and is less subtle sounding.
Anyone wanting to hear this writ large should check out another Fender hybrid (this time a guitar); The thinline or custom Telecaster.
It has the Fender rip-off of a Gibson humbucker right up at the neck, and the slanted 6-pole single-coil mounted in the bridge plate itself.
Can sound great, but I've watched mates at rehearsal wrestle with one all night to try to balance the volumes such that when you flick the selector switch, the levels stay the same (not an issue for the bass, though!)

[David Nimrod]

[quote name='Lfalex v1.1' post='143531' date='Feb 20 2008, 09:12 AM']The PJ, whilst a useful combination, can hum. How much is determined by the relative levels of each pick-up as determined by the volume controls.
The exception to this is if the J is a "stacked" or "side-by-side" design, which actually makes it a closet humbucker anyway! (Then there's the Twin J from the Deluxe P, but that's a different design again!)

I've always felt that the single coil aspect suffers relative to the split "P", which is possessed of a higher output, and is less subtle sounding.
Anyone wanting to hear this writ large should check out another Fender hybrid (this time a guitar); The thinline or custom Telecaster.
It has the Fender rip-off of a Gibson humbucker right up at the neck, and the slanted 6-pole single-coil mounted in the bridge plate itself.
Can sound great, but I've watched mates at rehearsal wrestle with one all night to try to balance the volumes such that when you flick the selector switch, the levels stay the same (not an issue for the bass, though!)[/quote]


+1 to that... I think pickups should ideally be matched in output...

How about the MM + J Sandbergs et al... that can't be good either?

[Lfalex v1.1]

[quote name='David Nimrod' post='143536' date='Feb 20 2008, 09:14 AM']+1 to that... I think pickups should ideally be matched in output...

How about the MM + J Sandbergs et al... that can't be good either?[/quote]

Ah...

They kind of get around that.
Most such designs;

Musicman H/S
Warwick Infinity/Dolphin/Vampyre
Equivalent Sandbergs et al

Have the HB or TJ at the bridge and the single J in the mid or neck position, where the string excursion is greater. Greater string excursion = Greater perceived output level.
This helps to fix the issue, particularly if the pole-pieces are "blades", which can detect/transcribe larger excursions than single / paired pole-pieces.
MEC (Warwicks) and Bartolini use the said blades in their MM / TJ and [i]some[/i] J designs.

[astar]

I'm on a steak-out for a old p-bass with a P-J setup, I spotted a late seventies with such a configuration.

I'm thinking of replacing the added volume-controle for a 3-way selector switch so I can either use both PU's or single out the P or the J pick-up, but...

Is this a hard thing too do and what switch do I need?
Will this cause the hum mentioned earlier and how to fix it?
If needed, how can I adjust output?

I appreciate all the help I can get, but please in layman terms for I'm not much of a technician.

Greetz
Aljan