J Bass Volume drop when humbucking?

[tomspn]

Hi,
I wired a J Bass using a set of Kent Armstrong's alnico pups.
When both pickups are at the same volume level they might be humbucking (as they should be) but above all there's a drop in volume! Is this normal? (when i turn the vol back on any pup, the overal volume gets louder)

thanks for helping me out!

[throbgod13]

Originally Posted by tomspn

Hi,
I wired a J Bass using a set of Kent Armstrong's alnico pups.
When both pickups are at the same volume level they might be humbucking (as they should be) but above all there's a drop in volume! Is this normal? (when i turn the vol back on any pup, the overal volume gets louder)

thanks for helping me out!

is seems like one of the pickups is 180 degrees out of phase..

check your leads from your pickups..

[BurningSkies]

Every Jazz bass I've had has done that. If you roll one of the pickups back just a touch, you'll get that fuller volume/tone.

[ibz]

Yes, change then from paralell to series if you don't like the volume drop. Although you'll get a different sound as well.

[RyreInc]

The volume drop is normal, and is caused by the changing impedance seen by each pup.

When you have both volume pots all the way up then each pup sees the other as a path to ground. This lowers the impedance to ground, lowering the volume. When you roll back a volume pot you re-introduce resistance between the pups, which increases the impedance seen by both pups, increasing the volume.

The pups are not out of phase--the tone would change (less bass, quacking sort of sound) if that was the case, instead of simply getting quieter. Nor should they be wired in series (unless you want to do that)! The most simple solution to this "problem" is to introduce some resistance between the pups, maybe around 100-200 kohms (I'm not sure of this value). This resistance is between each pup's output and the output jack, and would decrease your overall volume slightly.