Humbucker cover alloys and the effect on sound

[StarryNight]

I tried searching this info on the forum but without a difinitive answer. Mojo seem to have a nice selection of humbucker covers as identified as:
nickle silver - bare
nickle silver - chrome
nickle silver - nickle

i wonder if anyone can speak to the differences (if any) on tone or aesthetics.

[EFK]

JMHO, but anything with chrome on it will dull the sound to varying degree.

[big_teee]

I tried searching this info on the forum but without a difinitive answer. Mojo seem to have a nice selection of humbucker covers as identified as:
nickle silver - bare
nickle silver - chrome
nickle silver - nickle

i wonder if anyone can speak to the differences (if any) on tone or aesthetics.

I personally prefer Buckers without covers.
I've tried the mojo nickel covers they work pretty well.
Stay away from covers with brass, especially combined with a brass baseplate.
That combo doesn't give good results.
I've tried it over & over, same results.
Rock On!
Terry

[David Schwab]

I personally prefer Buckers without covers.

Me too. It must be a fashionable thing now, because people started removing their covers back in the day because they sounded better without them. Gibson probably only put metal covers on for extra shielding, since they were trying to make a quiet pickup to have something over Fender's noisy single coils. Leo knew that plastic covers were the better way to go.

[StarryNight]

I just inquired at greasygroove.com about their pickup covers and they said they were chrome plated copper and that "they don't affect the sound of the pickup whatsoever".

[David King]

In regards to the plating, chrome plating is almost always done over a layer of copper. the copper, being quite conductive will be more susceptible to eddy currents in that layer. That's my theory anyway. It may be that the 1/2 mil of copper has no appreciable effect.

[Rick Turner]

The highest quality chrome plating is copper/nickel/chrome; each sticks best to the previous layer.

Any conductive pickup cover will affect the sound to some degree because of eddy current loss. Metal covers are also somewhat microphonic as the cover acts like a moving coil and you're literally vibrating the eddy currents which couple to the pickup coil turns.

I now prefer plastic covers into which I've painted a thin layer of conductive carbon paint...Electrodag...connecting that to ground via thin self adhesive copper foil.

[big_teee]

The highest quality chrome plating is copper/nickel/chrome; each sticks best to the previous layer.

Any conductive pickup cover will affect the sound to some degree because of eddy current loss. Metal covers are also somewhat microphonic as the cover acts like a moving coil and you're literally vibrating the eddy currents which couple to the pickup coil turns.

I now prefer plastic covers into which I've painted a thin layer of conductive carbon paint...Electrodag...connecting that to ground via thin self adhesive copper foil.

I agree with you Rick. IMO There is no such thing as a Transparant metal cover.
What is the purpose of the conductive carbon paint and copper foil in the plastic cover.
I presume that's for shielding.
Also I have experienced the microphonics with the metal cover.
A question about chrome vs. Nickel.
Does Nickel plated nickel (Like Mojo's) have any copper or other metals besides nickel?
Terry

[Rick Turner]

The question is whether "nickel" covers are pure or near pure nickel or nickel silver which has a considerable copper content...and no silver at all.

The conductive paint is for shielding, yes. It's very thin compared to metal covers, and while there must be some eddy current loss, it's minimal. It is possible to absolutely minimize eddy current loss through clever shielding design, but there's also a point of diminishing returns where it might be good for bragging rights, but not really be noticeable in the real world. I am a fan of shielding pickups, though.

[David King]

Nickel silver is 60% copper, 20% nickel and 20% zinc. Notice there's no elemental silver in it at all. Remember that it's an alloy and as such it doesn't have to behave like the sum of it's parts.

[EFK]

Big teee, just about all of the aftermarket nickel covers have a copper layer under the nickel. The only alternatives of which I am aware are to either polish the raw nickel covers yourself w/ a buffing wheel or use Gibson burstbucker/57 classic covers, which look awful but are nickel plate directly on nickel silver covers, no copper layer involved.