Popping noise.

[UncleBalsamic]

I have a violin bass with metal pickup covers.

When you touch these it makes a popping sound, I'm guessing this might be a grounding issue but I don't know.

Is there any easy way I can sort this out?

Thanks.

[napalmito]

Do not make the strings in contact with the covers, I know this sounds dumb.
Even if you wire the covers to the ground, it will be the shock on the covers that produces the sound.
Lower your pickup(s) or raise your saddles, or hit the strings with less enthousiasm.

[UncleBalsamic]

I'll try that, but it's a pain becuse I rest my thumb on the pickups.

I might have to put something on them or make a thumb rest.

[UncleBalsamic]

I've sorted it now.