Copper plates on the back on pickups

[EliasMooseblaster]

I've only seen this once: when I opened the box of a Fender '62 RI pickup, to install in my Precision copy, I found it had a piece of copper mounted on the back. At the time, I assumed this was to help with earthing. Admittedly, I've not opened up all my basses to check, but I've changed a fair few pickups in my time and I've never seen it done anywhere else. I'd dismissed it as a bit of a curiosity until I saw this article: https://www.fender.com/articles/how-to/asked-answered-the-difference-between-strat-and-tele-bridge-pickups?tag=electric which claims that the "ashtray" around the bridge pickup of a Telecaster affects the tone.

Unfortunately, my own Tele is a variant on the classic design and has no such ashtray for me to test this hypothesis. On the other hand, I have found that the '62 RI pickup has made my Precision a lot more growly - though I'd always this was down to how it was wound. From a physics point of view, I can see how the magnet might well interact with the metal around it - but then by the same logic, people would surely start to favour chrome or plastic pickup covers for tonal reasons...anyone care to stick their oar into this one?

[samhay]

The copper plate was used back in the day for shielding.
The reissue pickups include it as they are trying to be period correct.

More info:
https://www.talkbass.com/threads/fender-p-bass-copper-plate.966965/

[TimR]

Modern bass cavities are painted with what looks like a black paint. It's graphite shielding paint.

[Geek99]

I purposely put one in my 75 replica - it has el cheapo internet pickups; everyone loves the sound and it's totally quiet noise-wise so either the copper plate adds something in sound, mass or resonance or it's a totally amazing bass anyway and adds nothing. It doesn't harm it; so I suggest putting it in. It was good enough for Leo

Edited April 8, 2017 by Geek99