How CAN P-bass be wired series/parallel?

[stubhead]

I have been wiring up my own six-strings for years now, and I am a big proponent of the series/parallel switching for humbuckings - in fact I prefer it to coil tapping because it doesn't halve your volume onstage. I am now putting together a fretless P-bass with a Warmoth neck & a DiMarzio pickup. I see they have a series/parallel wiring suggestion, and I don't understand - it's not a humbucking, right?

What is the series/parallel switch DOING, electronically, reversing the phase of one pair of strings? How specifically does this affect the tone? Being a fretless, I am figuring I want maximum brightness potential - 500k pot, .022 cap, though I don't want to add a Jazz PU, preamp or anything till I see how she blows.

P.S.(I have searched the forum already for this, to no avail)

[ehque]

Originally Posted by stubhead

I have been wiring up my own six-strings for years now, and I am a big proponent of the series/parallel switching for humbuckings - in fact I prefer it to coil tapping because it doesn't halve your volume onstage. I am now putting together a fretless P-bass with a Warmoth neck & a DiMarzio pickup. I see they have a series/parallel wiring suggestion, and I don't understand - it's not a humbucking, right?

What is the series/parallel switch DOING, electronically, reversing the phase of one pair of strings? How specifically does this affect the tone? Being a fretless, I am figuring I want maximum brightness potential - 500k pot, .022 cap, though I don't want to add a Jazz PU, preamp or anything till I see how she blows.

P.S.(I have searched the forum already for this, to no avail)

Each half is RWRP if i am not wrong, which means a P pickup IS humbucking. And that means that the parallel-series switch does exactly what it says it does, either connects the 2 half-pups in parallel, or in series.

Series is said to be brighter. Maximum brightness potential, get series wiring and a switch to take out the tone circuit.

[i_got_a_mohawk]

You can do a series/parallel switch, but it doesnt make much of a difference.

Also, coil tapping doesnt half your volume at all.

Series/parallel works best when using two seperate pickups that are a bit further away from each other.

[22pauld22]

you'll like the series para switch on the dimarzio model p .. works great with a fretless.
here in bass player land you might call a p bass pickup a split coil .. as with your 4 string you have a different coil for each two strings .. so in fact you have two single coils right beside each other .. which is pretty much a humbucker if you squint hard enough

very much like a split coil jazz pickup

the only way your going to know if you like it is if you try it .. so put the dpdt switch in temp style and see how you go ... para rolls the top off a little and thickens it up some .. you might not use it often but it is a nice option to have and you have alot of space in that p bass cavity .. if you end up installing a model j in the bridge position you can get a dual throw quad pole switch and wire both up to it .. thats what I have on my 4 banger fretless .. a nice subtle difference

I find it most useful if I'm using a brighter flat wound or a round wound on my fretless .. I can kick it back into parallel to take a bit of zing off if need be

hope that helps

[stubhead]

It seems like the only difference between the series and parallel in the actual signal coming out would be when you're playing the A and D strings together, when both "coils" are working - when you're playing on any single string, only one coil is outputting, right? Both coils on a regular guitar humbucking are sending signals on all the different strings simultaneously.

(I'm gonna wire in a DPDT anyway, I'm just curious....)

[ehque]

Originally Posted by stubhead

It seems like the only difference between the series and parallel in the actual signal coming out would be when you're playing the A and D strings together, when both "coils" are working - when you're playing on any single string, only one coil is outputting, right? Both coils on a regular guitar humbucking are sending signals on all the different strings simultaneously.

(I'm gonna wire in a DPDT anyway, I'm just curious....)

You are right, and you are wrong. It is true that when you're playing one single string, only one coil is outputting. However, it is outputting a signal into a circuit, and if you pay attention to the wiring, the series wiring has this signal loading into ANOTHER coil, (which has kilo-ohm class resistance and other capacitance/inductance effects), whereas the parallel wiring has this "other coil" in parallel. Telling you what effect this has exactly is beyond the scope of my knowledge, but you can see this: the tone will change, in the same way your tone knob affects the tone of the bass.

Regarding noise cancelling, noise usually comes from outside sources (lighting, CRT monitors) so it doesn't matter whether the coils cover the same strings or not. The noise affects both coils equally and if wound in opposite directions it will cancel.

[groucho]

I found wiring P Bass pickups with a series/parallel
pull pot, to be very useful if you are using really hot
P Pickups like Duncan Quarter Pounders -
You get a much lighter vintage kind of sound out
of them in parallel - have it on one of my basses.

Each coil contributes it's signal out of phase - with the noise
picked up by both being cancelled by each other - the string signal
which is magnetically induced is out of phase to begin with -
(north out poles on one bobbin and south out poles on the other)
so that ends up being right at the end. This is true if wired series or parallel.