Hi all, hoping to appeal to your generous nature I really need some help.
Having experienced my woeful pickup fitting skills before I bought a pre wired 50's les paul harness from Alegree of this parish.
Removed old emg's and pots.
Fit new harness, wire up pickups and switch and I have a grounding issue. Major hum on both pickups that goes away when I touch any of the hardware.
This is the harness.
http://i1131.photobucket.com/albums/m544/kevinstead/Mobile Uploads/Screenshot_20200103-184034_Samsung Internet.jpgI wired
Neck pickup to lug 1 of neck volume pot
Grounded braided wire to back of same pot
Bridge ground to back of same pot
Neck switch to middle lug of same pot
Bridge pickup to lug 1 of bridge pot
Bridge switch to middle lug of same pot
Switch ground to back of same pot
Switch hot to tip of input
Sleeve of input to back of bridge tone pot.
Any help is very much appreciated. I'm sure the harness isn't the issue, it's either I've soldered wrong or I've soldered poorly. Both are more than possible.
Thanks
Comments
Do you have the strings on yet? If not you'll get a much worse buzz when you're not touching the hardware. Some buzz when not touching the strings or other grounded hardware is normal with passive pickups, and if it goes away when you're touching the strings (or tailpiece if the strings aren't on yet) then it is grounded correctly.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I’m assuming this is buzz and not hum, by the way, since it goes away when you touch the hardware.
You also have a ground loop around the pots, which is not ideal, but that will cause a slight hum which is not affected by touching anything.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Yeah its buzz not hum, my fault sorry.
How do I remove the ground loop?
Really appreciate your help.
The ground loop on the pots is because the braided cables from the pickups are touching each other. You either need to put sleeving on these so they’re not, or remove one of the links between the pot casings.
My preferred way of doing it is to make the neck volume the ‘master’ ground, the neck tone and bridge volume connected to it (which means you don’t need to worry about the braided cables), and the bridge tone to the bridge volume.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Do you think I need to replace whole switch wire part for one with a shield?
Personally, I prefer to use three pieces of standard braided cable, one directly from the jack to the switch and two from the switch back to the volume pots, exactly as Gibson did it traditionally. The only thing you need to watch out for is the bare braiding shorting against any of the terminals on the switch or the controls, you either need to make sure it stays out of the way or put some sleeving on it.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein