Earthing Issues with two builds

TimberG

I have a very frustrating issue on two build I have completed wherby i have serious buzzing from the electronics. Now i things its down to a bad earth but not sure, you can here the grounding on touching the bridge etc. Now i have checked the following

1- Bridges are both earthed and earth wire is on tone pot (earth is soldered to the bridge)
2- All pots have earth wires going to them in loop (except last pot)
3- I dont think i have any dry joints (how can you tell)

I though I may have fried a pot so have changed this but still the same problem. The only thing i have not done on one build is shield the cavity but on one all cavities are shielded with foil.

1st build = tele style with twin seymour duncan hot rails (no coil tap) into a normal 3 way tele switch. 500K pots 0.22uf cap
2nd build = tele style with twin S/D humbuckers coil tapped only, way switch, 500k pots with 0.47uf paper in oil caps

Help needed please 

Tim
 

Sporky

Just to clarify, does the buzz go away when you touch the strings?

If so it's a shielding issue, not a grounding one. The bridge is earthed, so when you touch it you're earthed too and your body acts as a shield.

TimberG

Thanks Sporky yes the buzz does go away when you touch strings, also when you touch the the bridge as well

would you recommend the shielding paint or foil tape for best results.? i have foil taped the build with hot rails and it is still buzzing

thanks for your input 

Oh nice workshop build thread btw

Tim

Sporky

Ta - hopefully I'll be back to building early in the new year.

I've only used paint for shielding. I think either will work fine, it's probably about personal preference - which you find easier to apply.

I'd check that the foil is grounded if you're still getting buzz - probably obvious, but sometimes rechecking all the obvious things gets you there.

Jimbro66

Sporky said:

I'd check that the foil is grounded if you're still getting buzz - probably obvious, but sometimes rechecking all the obvious things gets you there.

I had exactly that some years ago when someone brought a guitar to me that had been carefully shielded but with no ground connection to the shielding. An easy fix.

TimberG

Jimbro66 and Sporky Thanks....check and check again is the name of the game

Cheers 

Tim

ICBM

I much prefer copper tape for shielding, and I find it's more effective - but for the best result you need to go nuts and put a solder joint between every two pieces to make absolutely sure it's all connected - just one spot is enough, you don't need to do the whole seam. The 'conductive' glue on it quite often isn't very. As already said you need to make sure it's actually connected to ground too - if there's no reliable contact point, solder a wire on.

I recently re-shielded an active bass which had paint shielding, using copper tape, because the paint wasn't doing the job well enough. It made a very noticeable improvement.