Noisy Samarium Cobalt (Fender SCN) Jazz neck pickup

Anonymous Guy · #1 06-10-2009, 05:55 PM

EDIT: I made a mistake while making this topic, it is in fact the bridge pickup that is making all the noises.

A while back I had my tech drop in a set of Fender SCN pickups in my Jazz bass.

While I do like the tone, the bridge pickup is very noisy, both soloed and when blended with the neck pickup on full. I brought it back to my tech and there didn't seem to be any noise issues in his shop, however when I'm playing at home, the noisiness of the neck pickup comes back.

Help?

B String · #2 06-10-2009, 05:57 PM

When I had that issue, I had my tech (his idea) put a strip of
Copper on the bottom of the pickup. It worked.

Anonymous Guy · #3 06-10-2009, 06:03 PM

I have some copper foil tape - should I have the foil cover the wire/solder joints as well?

B String · #4 06-10-2009, 09:54 PM

Quote:

Originally Posted by Anonymous Guy

I have some copper foil tape - should I have the foil cover the wire/solder joints as well?

err...umm...err.....not sure. Mine just has a slightly oversize
piece of Copper foil taped to the whole underside of the
pickup

Anonymous Guy · #5 06-10-2009, 09:58 PM

I tried it out - it ended up completely cutting off the pickup's signal when the foil touched the white wire's solder joint.

I made some strategic cuts to the foil and it reduced a bit of hum, but it's not completely quiet. Oh well, it'll do for now.

SGD Lutherie · #6 06-12-2009, 08:54 AM

Quote:

Originally Posted by Anonymous Guy

I made some strategic cuts to the foil and it reduced a bit of hum, but it's not completely quiet. Oh well, it'll do for now.

Is the foil grounded? it has to be grounded to shield the pickup.

Anonymous Guy · #7 06-13-2009, 11:45 PM

Quote:

Originally Posted by SGD Lutherie

Is the foil grounded? it has to be grounded to shield the pickup.

Not exactly - I followed the above poster's strategy and attached a strip of foil to the bottom, but didn't solder it to the pickup.

For a supposed "noiseless" set of pickups, it doesn't reduce single coil hum very well.

joeyl · #8 06-13-2009, 11:53 PM

could it be an issue with your home wiring/lights setup etc? how about when you play in other places?

SGD Lutherie · #9 06-14-2009, 10:32 AM

Quote:

Originally Posted by Anonymous Guy

Not exactly - I followed the above poster's strategy and attached a strip of foil to the bottom, but didn't solder it to the pickup.

If the exposed ends of the pole pieces are grounded, which they should be, and the foil you used has conductive adhesive (the stuff from Stew-Mac does, some doesn't), then that will work. If not, I'd solder a wire to the foil and ground the other end of the wire.

Quote:

For a supposed "noiseless" set of pickups, it doesn't reduce single coil hum very well.

There are two kinds of interference, magnetic field, and electrical field, and humbuckers only cancel the magnetic field noise. That's the low 60 or 120 cycle hum you hear.

The other stuff is the high pitched buzz. Humbuckers don't cancel that. So you need shielding to get rid of the buzz. It's possible that the SCN pickups are not shielded well, if at all.

I also keep seeing reports that some are noisy and some aren't. That sounds like a quality control issue at Fender.

Bill Lawrence designed the SCN pickups. I'd bet the pickups he sells are nice and quiet.

Anonymous Guy · #10 06-14-2009, 02:29 PM

Quote:

Originally Posted by SGD Lutherie

If the exposed ends of the pole pieces are grounded, which they should be, and the foil you used has conductive adhesive (the stuff from Stew-Mac does, some doesn't), then that will work. If not, I'd solder a wire to the foil and ground the other end of the wire.

There are two kinds of interference, magnetic field, and electrical field, and humbuckers only cancel the magnetic field noise. That's the low 60 or 120 cycle hum you hear.

The other stuff is the high pitched buzz. Humbuckers don't cancel that. So you need shielding to get rid of the buzz. It's possible that the SCN pickups are not shielded well, if at all.

I also keep seeing reports that some are noisy and some aren't. That sounds like a quality control issue at Fender.

Bill Lawrence designed the SCN pickups. I'd bet the pickups he sells are nice and quiet.

I appreciate the detailed and informative response - the foil strip I used in fact was a strip of adhesive Stew Mac tape if that clears anything up. It didn't completely silence the buzzing (you can hear slight popping when you pluck a string without grounding the other strings with your left hand), but it is significantly much quieter. If it makes any difference, the bass is wired to CTS 500K pots since the pickups were stacked single coils.

Also when we had demo'd the bass at my tech's shop, it was completely silent. I dont understand this - the other humbucking pickups in my room - Quarter Pounder Split-P/Duncan JB don't react the same way and are completely silent. Its just the bridge position of this particular pickup. Maybe it has to do with the non-traditional magnetic composition of this pickup.

SGD Lutherie · #11 06-14-2009, 03:25 PM

Quote:

Originally Posted by Anonymous Guy

Maybe it has to do with the non-traditional magnetic composition of this pickup.

I'd try running a ground wire from the foil. It sounds like that one pickup lost its ground connection to the metal parts.

The magnets don't affect that... the pickup is pretty much a set of steel pole pieces that run through both coils. between the coils are steel "moderator bars" that touch all the poles, and the magnets stick on those.