Grounding magnets?

[SK66]

I noticed in a post that David King said he grounds his magnets for noise cancellation (i.e. shielding). Does anyone else?

Obviously a HB or P-90 is generally fully grounded (but not necessarily so).
In a Tele pickup the rods might be grounded, but generally not.

I make a design where the singlecoil alnico rods can easily be grounded. I found this generally cut a notable amount of top end and made them seem "smoother".
I can see where this could be usefull for changing character, but I can't say the pickup was notably quieter. The design uses a grounded frame either way, so maybe there is enough shielding anyways...

So, does anyone else ground the mags in a singlecoil, or experimented with it?

[Dave Kerr]

When I made a couple blade humbuckers with laminated blades, there was a weird oscillating sound that didn't go away until I connected all the metal to the drain wire. I didn't notice much hum either way.

[David Schwab]

I also ground the blades and any other metal parts in my pickups.

[David King]

Steven,
It's funny you should mention this about the top end going away. I have tried grounding other manufacture's magnets and found that it completely killed the tone. DCR didn't change so I don't think it was a coil short but I'm still trying to figure out what happened.

[pupoholic]

in the sidewinder dual coil design we had to keep the alnico 5 rods grounded or they would Buzzzzzzzzzzzzzzzzzzzzzzzz LACEHOLYGRAILS

[salvarsan]

I make a design where the singlecoil alnico rods can easily be grounded. I found this generally cut a notable amount of top end and made them seem "smoother".
I can see where this could be usefull for changing character, but I can't say the pickup was notably quieter. The design uses a grounded frame either way, so maybe there is enough shielding anyways...

Did you see a difference in inductance or AC resistance on the Extech?

The change in sound could be from eddy currents.

Joe Gwinn may want to weigh in on this one.

-drh

[Possum]

...

if the top end is going away the Extech should see it in the AC resistance going up.

When I did my P13 repro set, one of the earliest Gibson versions the magnets were taped to keep them from being grounded. All the later versions they were bare.....

[RedHouse]

I ground the poles in all the pickups I make, and when I can, even the rewinds. IMHO there's no excuse for having a noise antenna as the core of your electro magnetic device.

This was one of my 1st experiments with grounding A5 rods:


(the goo around the rods is super-glue)

I pulled the rods out of the plastic bobbin, added a shunt wire about #28 solid wire jumper in between each pole hole, pressed the mags back in, then soldered the jumpers together like the pic shows, is was quick-n-dirty but proved the point (to me anyway) that grounding poles reduces noise a bit.

IMHO with grounded poles, shielded scratchplates and shielded covers one can have a VERY quiet single coil, and still enjoy the single coil sound without automatically resorting to stacking an aux-coil for bucking hum.

While they do cut a miniscule amount of highs, the tradeoff is worthy (IMHO)

Note that the grounding doesn't reduce transformer type EMI (standing directly in front of an HV tube amp, or TV) but does noticably reduce stray and mains wiring EMI. (guitar at rest, volume up ready to play such as one does often when tracking/overdubing in a studio)

I have opinions about this (may incite debate) but I liken it to my experiences in racing (NHRA sportsman class) where after doing all the obvious stuff (CAM/HEADS/CARB/INTAKE etc) the rest of the "performance" gains to be had are a lot of little things that need to add-up to give an edge, IMHO this is one of them.
(grounding poles/magnets, that is)

...I have tried grounding other manufacture's magnets and found that it completely killed the tone...

My experimenting has found that in traditional Strat type coils, grounding the rods seemed to add some high-killing capacitance (wire too close to ground I suspect) but using the plastic bobbing type didn't do that, and also when coating a traditional style Strat pickup's rods with enamel (coat of paint) like I did here on my Rick clone seemed to stop that too:

[David Schwab]

This is interesting. I haven't noticed loosing any highs, but then I haven't done an A/B. I can disconnect the ground wire while the pickup is connected.

One more thing to try...

[Joe Gwinn]

Did you see a difference in inductance or AC resistance on the Extech?

The change in sound could be from eddy currents.

The AC resistance in particular would go up.

Joe Gwinn may want to weigh in on this one.

It sounds like the inside of the coil is hot and the insulation between wire and core is very thin, so when the cores are grounded the self-capacitance goes way up.

I suppose that if different turns were shorted to different cores, connecting the cores together would have a big effect, but this seems a bit of a stretch.

I would ground the cores, and solve the problem by having enough insulation on the cores so shorts don't happen, and the capacitance is reasonable.

[RedHouse]

Just to be clear, when I said:

...grounding the rods seemed to add some high-killing capacitance (wire too close to ground I suspect)

I meant to imply it was just a very minor loss, not a night-n-day thing, but noticable if you are looking for it, and insulating the poles/magnets solved that for me.

...I can disconnect the ground wire while the pickup is connected....

That is what I did, and how I noticed, but again it was a very minor effect perhaps un-noticable unless one is looking for a difference.