Precision Earth Hum

[cd_david]

A loud earth hum appeared on my 73 precision yesterday, I've re soldered all joints and re sat the bridge earth but it still hums and disappears when I touch metal. Any thoughts?

[KiOgon]

Have you tried a new/good lead?

[Geek99]

I would get a multimeter and check each piece wire for continuity

[cd_david]

[quote name='KiOgon' timestamp='1462970115' post='3047385']
Have you tried a new/good lead?
[/quote]

Yes, tried multiple leads and in two separate properties with two different amps. The re soldering and shortening a couple of cables helped a bit but still obvious at high volume

[rmorris]

[quote name='cd_david' timestamp='1462969630' post='3047377']
A loud earth hum appeared on my 73 precision yesterday, I've re soldered all joints and re sat the bridge earth but it still hums and disappears when I touch metal. Any thoughts?
[/quote]

I know it's an obvious thing to say (and you have resat the bridge) but you do really need to check continuity between the bridge and the output jack.

[luckydog]

^ what rmorris says +1

LD

[pfretrock]

I've had this on my P. the original crap quality socket was replaced after 18 months as the plug kept falling out. Replaced with a Switchcraft part 6 months ago, now sometimes I get hum with this until I touch the strings. I believe the problem in my case is poor earth connection between the plug collar and socket. Plug is Neutrix, so no problem there. Nickel plating is not the best low resistance contact material!

[rmorris]

[quote name='pfretrock' timestamp='1463323715' post='3050451']
I've had this on my P. the original crap quality socket was replaced after 18 months as the plug kept falling out. Replaced with a Switchcraft part 6 months ago, now sometimes I get hum with this until I touch the strings. I believe the problem in my case is poor earth connection between the plug collar and socket. Plug is Neutrix, so no problem there. Nickel plating is not the best low resistance contact material!
[/quote]

You don't have a problem with the Switchcraft socket. The point of the earth/ground connection of the strings/bridge via the socket is that it 'grounds' you when you touch the strings/bridge. Otherwise you tend to act as an antennae for noise and this gets picked up by the bass pickup/electronics. (note that if you touch something else that is earthed - eg amplifier chassis screw then the noise should also reduce).
Nickel plating is fine and adds no significant resistance. The problem with jack/plugs is more likely to be mechanical and now that you have replaced the poor socket the Switchcraft/Neutrik product should be fine. If there's a problem with the plug or socket - either mechanical or dirt/grease/corrosion then you will hear it in the sound breaking up.