P/J Bass question

[mick]

Anyone know the wind direction and polarity of the P Bass pups?? J Bass too..
Spence did tell me ( thanks Spence..) but I have forgotten as it was a while ago , I have lost the email and don't want to pester him again..
Thanks..

Mick

[black_labb]

not quite sure i can help.

i understand that the p bass coils are both wound opposite directions (switched leads to get the same effect probably), so i dont know if it really matters. i'd have the magnetic polarity being opposite to avoid low output on the a and d strings. the question would be valid for the j though.

i recently was having a debate on a different forum with someone. i was saying that pbass pickups dont nessesarily need the different coils to have opposite magnetic poles to cancel out the hum. he felt that opposite magnetic polarity was nessesary for the pickup to cancel the hum like a humbucker.

i think that the same magnetic polarity would mean that the a and d stringss (on a 4 string) would have a bit less output than the others due to some signal cancellation, but thats not what the arguement is about.

i was right, wasnt i? (will link him to this thread to finish the arguement)

[David Schwab]

i was right, wasnt i? (will link him to this thread to finish the arguement)

You can do it either way because unlike a Gibson style humbucker, no string is picked up by both coils.

However... There is an issue with having two strings out of phase against the Jazz pickup... It's been a while since I wired up a P/J bass, so I forget which way it's done, but I just had a Pedulla bass in the shop with Bartolini P/J pickups, and the P had opposite magnet polarities on each coil.

[black_labb]

You can do it either way because unlike a Gibson style humbucker, no string is picked up by both coils.

However... There is an issue with having two strings out of phase against the Jazz pickup... It's been a while since I wired up a P/J bass, so I forget which way it's done, but I just had a Pedulla bass in the shop with Bartolini P/J pickups, and the P had opposite magnet polarities on each coil.

thats what i thought. good point about the p/j bass though.

is there noticeably less output at the strings where the 2 coils are split due to phase cancellation, or is this not noticeable?

[David Schwab]

is there noticeably less output at the strings where the 2 coils are split due to phase cancellation, or is this not noticeable?

It has no effect at all. They look like they overlap, but in practice they don't. It could be the big distance between strings.

Even with split Jazz pickups, like the DiMarzio Model J, you get no cancelation between the A & D.

[Spence]

P Bass clockwise both coils, one North up, one south up. Same principle as a Gibson humbucker.

J Bass neck North up, clockwise wound, bridge south up and counter clockwise.

Write it down somewhere. I can send you a crayon and a pad if you like Mick.

[Achiles]

Serie/paralel ,once indutance changes,how should be the P. sound?

[GlennW]

Jason's book shows both P coils wound ccw with the starts connected, North coil has the hot lead, South coil has the ground. Don't know if they changed over the years or not.

[mkat]

i recently was having a debate on a different forum with someone. i was saying that pbass pickups dont nessesarily need the different coils to have opposite magnetic poles to cancel out the hum. he felt that opposite magnetic polarity was nessesary for the pickup to cancel the hum like a humbucker.

Why bother doing it this way? It ends being a pain especially when the owner wants to change configuration (eg. David's point about the P/J setup).

If it was a winder mistake that the pickup ended up this way, the option is there to fix it by switching polarity anyway.

[mick]

Thanks heaps guys.....

Pink Pleese Spence...I pwomise Iwont eet it an wite on the wawls:rolleyes:

[Spence]

Ah shit Mick, I've used all the pink ones to wax pot my fake English PAFs. I think that may have been the giveaway.

[mick]

Never mind , I'll nick some off the kids if they haven't fed them to the turtle or something??