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jmeek811
07-10-2013, 01:15 PM
Hey Guys!

I have 2 things..I was wondering if anyone had any ideas on before I start re-wiring things.

My LP is humming when I plug it in, it stops when I touch a pick up or the 3way or the input jack. Its more defined on the bridge pickup. Is that a problem with the grounding?? I am not sure I want to plug it in again until I have fixed it

Also on the bridge pickup only between about 80-90% volume it cuts out, when i go past there and before there its fine.


Other then that I love it :)

Gavin1393
08-10-2013, 01:15 AM
Check your output jack and make sure the wires haven't been reversed.....Been there myself and done that...

When wiring your guitar you create a circuit. The humming sounds you expect to filter out of the guitar via the earth/ground wires...
When your guitar is silent until you touch the strings (which are in contact with the bridge, which in turn is [supposedly] in contact with the earth wire) what is happening is that your body is becoming the earth wire. This suggests that your bridge isn't running through to ground until you touch the strings and hence are completing the circuit to ground.

Switch the output Jack wires around and see if that makes any difference. If not check all your ground joints especially at the solder points. You may have a dud joint.

This may solve the Pot issue, but if it doesn't, change the pot...the pot may either be faulty or dirty.

dingobass
08-10-2013, 11:24 AM
Yerp, I am with Gav.... been there, done that!

Scott J.
09-10-2013, 06:46 AM
I guess as long as its humming the same tune that you're playing it could be bonus ... saves to having to pay for a back-up singer! :D

... sorry 'bout that, I'll go now ...

SIMpleONe89
17-10-2013, 04:50 AM
I also experience the same problem but the hum goes away when I play outside in the living room with the same amp. I shielded the guitar too, but I suspect it's caused by EMI. That's annoying!

wokkaboy
17-10-2013, 05:23 AM
Another possible cause of a hum is a mobile phone. Make sure there is no mobile phone near the guitar or amp.

lawry
17-10-2013, 09:07 AM
Another thing worth looking for is dry joints. Check that all soldering is nice and silvery, not frosty. Also check that there is good jointing between the wires and tabs or pot housings. If in doubt, resolder the joints and get a good flow with good heat. Don't overheat the joint but make sure that the heat is there long enough for the solder to run properly.

SIMpleONe89
17-10-2013, 10:35 AM
I also noticed certain kinds of lighting and also computer monitors have made it worse.

lawry
17-10-2013, 04:38 PM
Sounds very much like a shielding/grounding issue to me. I'd be checking those first.
Did you shield the cavities? If so, did you connect/solder the shielding to the ground of the rest of the electronics?

DanMade
17-10-2013, 08:38 PM
I have the exact same problem with the LP that I have recently wired up. I have triple checked my wiring and solder joints and they all look good.

I haven't shielded the cavity's, I am going to shield them today and see if that helps.

I am thinking the three way switch may be the cause. I just don't like the look of it, and I suspect it may have grounding issues. I will also try replacing the tree way switch.

I also question if the ground wire has a good purchase on the bridge post. I'm 99% sure it's fine, but you never know

The hum is not too bad at home with few interference's, but in my mate's music room that's full of electronic's the hum was unbearable. The most hum I've ever heard from a guitar.

lawry
18-10-2013, 11:15 AM
Hey Dan,
If you have a multimeter just check the resistance between the post and the outside of the output socket. If you don't have a multimeter try getting a short bit of wire, strip both ends and then connect it externally between the post and the shell of the guitar lead jack. If the problem goes away you know you have a wiring issue inside.

DanMade
18-10-2013, 11:36 AM
Thanks for the tip Lawry. I have a multimeter, so I will try this out.

stan
18-10-2013, 09:00 PM
/<\\/p>[]<\\/p>/Quote from lawry on October 17, 2013, 20:15
Hey Dan,
If you have a multimeter just check the resistance between the post and the outside of the output socket. If you don't have a multimeter try getting a short bit of wire, strip both ends and then connect it externally between the post and the shell of the guitar lead jack. If the problem goes away you know you have a wiring issue inside.

good tip from Lawry

the multi meter should read low/no resistance, as both should be earthed

lawry
19-10-2013, 01:22 AM
Good call Stan. Not much point telling someone to check between two points if you don't tell them what to expect.