paralelling vs series on a split coil hb

[black_labb]

hi guys

im planning to make a hollowbody guitar with pickups similar to p90's but wanted to make them split coils to eliminate the hum. i want to have the electronics quite versatile, so was thinking of putting a series and a paralell switch for the coils (as well as one for the 2 pickups as well).

what effects will the series/paralell switch have. from thinking about it, it seems to me that there wont be a big difference in output, as there wont be the 2 coils on the same string. as always, im interested in the tone difference. will 2 settings be different enough to make it worthwhile?

i know some fender p basses have the switch, and ive heard its not particularly liked by many. is it not versatile enough, or do people jut not like the voicing of the paralell much.

thanks
luke

[David Schwab]

I've had series/parallel switches on P bass pickups. Some people don't like P bass pickups in parallel because they sound thinner and brighter. EMG-P pickups have the coils in parallel. I guess that's not the tone some people want from a P bass.

The difference is a brighter tone in parallel, and a fuller tone in series. The difference gets bigger as you wind the pickup hotter.

[black_labb]

I've had series/parallel switches on P bass pickups. Some people don't like P bass pickups in parallel because they sound thinner and brighter. EMG-P pickups have the coils in parallel. I guess that's not the tone some people want from a P bass.

The difference is a brighter tone in parallel, and a fuller tone in series. The difference gets bigger as you wind the pickup hotter.

thanks for the help.

thats what i thought, but i wasnt sure if the reason most people disliked the switch was the sound or the fact that it wasnt very different. good to hear. looks like thats what i'll be doing.

[David Schwab]

I've wound a few pickups that sounded better in parallel. They were wound on the hot side and were a bit too muddy in series. The tone in parallel was different than if I wound the pickup with fewer windings and had it in series.

[black_labb]

I've wound a few pickups that sounded better in parallel. They were wound on the hot side and were a bit too muddy in series. The tone in parallel was different than if I wound the pickup with fewer windings and had it in series.

seems like just the effect im looking for. thanks for the help.

did you happen notice a difference in volume?

[bbsailor]

Black Labb

Changing the coils form series to parallel has the same effect as changing a tone filter. Here is why.

Assume that the single coil has a resistance of X Ohms, then two coils in parallel will have a total resistance of X/2 Ohms. If the coils are in series the total resistance will be X * 2. Assuming the load on the pickups remains constant and a high impedance, the change of resistance between series and parallel will alter pickup impedance and tone as well as the output level of the pickups with the series connection being louder.

If the pickups are going into a lower impedance amp input in the 10K ohms range, the parallel connection may sound a little louder.

The impedance of the pickups between series to parallel had a 4 to 1 ratio with series being 4 X higher than parallel.

I hope this helps?

Joseph Rogowski

[Steve Conner]

I agree with what bbsailor said. I have an old Westone Super Headless bass with humbuckers, and a switch to swap them between series and parallel humbucking operation.

Throwing the switch to series makes it sound louder (twice the voltage) and fatter (lower resonant peak). It also increases the effect of the tone knob. It's basically like a coil tap, but keeping the humbucking effect.

I tried rewiring my old Peavey bass so that it put both pickups in series when the selector switch was in the middle. But they were fairly hot pickups to start with, and it ended up distorting my amp too much even with the gain turned down as low as it could go.

[black_labb]

would the output not be the same, as the coils do not overlap on strings, so the voltage not double?

everything else makes complete sense though.