Guitar wiring

C

Cooperman

New member
It's too long a story to explain but yesterday I re-wired my guitar. 2 humbuckers, 3 way selector and 1 volume pot.

Now I have a nasty hum when I play thru my amp (only noticeable on the high gain channel) ... the hum disappears when I touch a string or the bridge... I'm assuming it's a grounding problem.

Just to check I re-wired everything correctly... the wires coming from my pickups went to the three way selector, then to the volume pot then to the jack. Each pickup has a shield and two wires - one red and one white. I earthed the shield and the white wire and wired the red ones to appropriate place on the switch. Is this correct?

I'm confident the rest is ok so I won't bother with the details. The thing I'm not sure about is whether the white wire from the pickup should be going some other place than to earth.

As well as this hum I've also noticed that when I roll of the volume on the guitar (thru the high gain channel of my amp), instead of the sound cleaning up like it used to it the distorted remains unchanged until literally the last 10% or so of the turn of the pot and then instead of cleaning up it just goes to mud. Any clues to why? Time for a new volume pot?

I'm thinking just about getting a new volume pot,a new switch and a new jack and start from scratch.

Also on the grounding thing... could the problem be on the jack on my amp... should I look into that too?

Thanks for any help
 
have you grounded to the bridge on your guitar? I have a guitar with the same problem - hums until i touch the string. The ground to the bridge had come upsoldered. There is some debate about the practice of grounding to the bridge as it sends current to the strings and has the potential to shock you if you touch metal/other devices like a Mic. There is a way to reduce this threat though, by inserting something (i am not that electronics experienced - can't remember if it is a capacitor, resister, etc.) between the ground and the bridge
 
Adam is correct.Your bridge ground wire must not be connected.The hum going away when you touch the bridge or the strings is a dead giveaway.
You have ( most likely) a volume pot with a log. curve,as opposed to linear curve that are available but rarer.Linear means the volume decrease in in proportion to the distance travelled by the knob.Logarythm curves have all the action from about 7-10.So your experience is just the opposite of what you should expect,if you don't get the vol decrease till the bottom of the knob's travel.
The heat required to get a good solder joint can mess up a volume pot easily.They are cheap and I would reccommend replacing it.If you don't have the resistance values,get a pickup diagram from Gibson and use an exact replacement or your tone will change.
While you are in there,you might want to consider shielding the cavity.Each solder point in there is unshielded and they act just like little antennea for stray RF.Aluminum foil lining the cavity and glued to the underside of the cover will create a little faraday cage to protect from picking up unwanted radio noise,flourescent light hum,etc.
Tom
 
Thanks guys. I'd say I screwed up the volume pot with the soldering iron because it worked fine before I started messing around with it. I'll get a new one. I've replaced it a few times before so that's not a problem.

The earth wire from the bridge to the case of the volume pot is good... I think. I'll take a multimeter home with me tonight and check all my connections. But because all the components in the guitar are earthed via the cable coming from the amp, couldn't the fault be anywhere along the chain - bridge to volume pot to guitar jack to cable to amp jack to earth wire in the amp... if there is a problem in the earth wiring at any point along this chain it would cause the problem I'm having wouldn't it?
 
You must log in or register to reply here.
Back
Top