Post Number: 1783
|Posted on Tuesday, November 21, 2006 - 6:20 am: |
I just installed Alembic "Strat" pickups and electronics in my Fender Strat XII. The problem is that it apparently isn't grounded as it hums and squeals until I touch the bare metal of the Q switch. How do you ground these? I can't just solder a wire from the bridge to the back of the volume pot - it's plastic! Anybody out there that can steer me in the right direction?
Thanks, Bill, tgo
Post Number: 960
|Posted on Tuesday, November 21, 2006 - 6:28 am: |
Try soldering a (ground wire)to the 1/4 jack post (bottom portion)to the wire leading to the bridge.by-passing the volume pot.
Post Number: 1142
|Posted on Tuesday, November 21, 2006 - 6:49 am: |
Not sure about the after-market sets, but in a 'proper' Alembic the shielding paint acts as ground. All metal parts touch the shielding paint, and you're grounded.
Apply shielding paint to the cavity (after dismounting all the electronics). If the cavity has a plastic cover then paint the inside of that as well. Make sure that the paint in the cavity and the paint on the cover touch, so spread the paint from the cavity onto the ridge where the cover sits.
Post Number: 3816
|Posted on Tuesday, November 21, 2006 - 12:30 pm: |
Bill - surely you had the cavity shielded? The system is self-grounding as adriaan notes.
If you're still having grounding, issues, I have a feeling we'll be seeing you soon.
Post Number: 1788
|Posted on Tuesday, November 21, 2006 - 12:39 pm: |
Thanks everyone, and Mica, in the infamous words of Peter Graves:
DON'T CALL ME SHIRLEY! hehehehehehehe
or, more appropriately in this situation, I should quote Homer Simpson:
In other words, off to the Stew-Mac site for shielding paint.
Post Number: 217
|Posted on Tuesday, November 21, 2006 - 2:45 pm: |
Hey, shielding the cavity won't hurt, but in the short term you should be able to get significant buzz reduction by doing a simple grounding of the bridge. Keavin's way will work (the lug he's describing on your output jack is the "sleeve" or ground lug). You may be able to more easily access the ground by removing one of the pots (e.g., take off the control knob and remove the big nut that's threaded on to the pot's shaft). Find a big, thin washer that the pot shaft can fit through, then put it on the shaft first, then reinstall the pot in the body. Any exposed metal part of the pot body is ground, and there may have been a lug, but if there wasn't, then you can solder the bridge wire onto this washer. It may be challenging to find a washer big enough and thin enough to work well, so if you don't find anything at the hardware store, you can see if they'll give you a little scrap of sheet metal flashing which you can cut a hole in and use as a ground lug. You'll only need about a 1" square piece, so they'll probably just give it to you.
Once you've grounded the bridge, the strings and your body will act as shields while while you're in contact. The bad part of this is that you can accidentally become part of the AC circuit if there are any grounding issues with your amp or any of the other equipment on the stage. You should take proper precautions, since the line voltage can be lethal! If you shield the cavity of your instrument, it will pose the same potential danger to you.
Post Number: 2006
|Posted on Thursday, January 11, 2007 - 1:50 pm: |
Hey everyone, I ordered the shielding paint from Stew-Mac, along with some copper tape. With the holidays and everything, this project got put on the shelf - literally - the one I built over the closet just for guitars. Anyway I started painting the cavities (main and recessed jack) with shielding paint last weekend - 3 coats 24 hours apart, and coverd the back side of the pick guard with copper tape. I put it all back together last night and VOILA! No hum! My wife was duly impressed. Can't wait for Saturday when I get to plug it into my rig at the studio. So far it sounds great on my little Fender Frontman 25R at home. Alembic electronics and 12 strings were meant for each other. Thanks to everyone for your help.
Post Number: 117
|Posted on Thursday, January 11, 2007 - 2:17 pm: |
Bill- BTW it wasn't Peter Graves, it was Leslie Nielsen of Police Squad fame.
Mike (the trivial one)
Post Number: 731
|Posted on Thursday, January 11, 2007 - 6:33 pm: |
"I just want you to know... We're all counting on you."
Post Number: 301
|Posted on Saturday, January 13, 2007 - 6:47 pm: |
So is the shielding paint the only way to go?
Or will the hard wire approach be ok?