Official Luthiers Forum!

I was recently working on a bass that required some electronics work. Everything worked well fixing some broken wires but the customer also wanted less hum in the pickups. Based on my experience the pickups sounded like your classic single coil pickups. If you position yourself in certain orientations you get a 60 cycle hum through the pickups...turn the bass 90 degrees and the hum goes away. The problem also seemed to persist when both the bridge and neck pickups were both on which seemed odd to me. Does anyone know of anyways to mimimize the hum while still using the original pickups and wiring?

_________________
Brad
Avon, OH

If you have trouble shooed all areas where there might me a short and if you have shielded it from Amp hole to break fast, and if you have re wired all the wires and if you have changed the pots ... and its still humming, change the pickups.

If that don't do it ...then unplug the sucker, heave it, and take an oath to only work on acoustics.

blessings
the
Padma

_________________
.

Audiences and dispensations on Thursdays ~ by appointment only.


.

Brad,

It has been awhile since I worked with magnetic pickups but IMHO that is the nature if the beast for fender single coil pickups. The pickups are coils of wires around a magnet that produces a magnetic field. With the vibrating strings produces a changing magnetic field, inducing a change in voltage in the coils, making sound. However, magnetic fields outside the pickup (like for the transform in your amp, florescent lights, or anything else that carries current) will produce a magnetic field that can be picked by the coils. When the hum is the loudest the coils are oriented so the field passes through the loops of wire in the pickups, inducing voltage into the coils, producing hum. I you turn 90 degrees, the field no longer passes through the coil and the hum reduces. This article has pretty good info http://en.wikipedia.org/wiki/Humbucker

You can try shielding the cavity with well grounded heavy gauge copper (making a Faraday cage) but since the pickups can not be completely surrounded this will only somewhat reduce the hum.

Those look like interesting basses. Good luck.

_________________
Eddie Lee