Guitar processor noise...? BZZZZZZ!

Has something changed? Any new cables? Different guitar? Did he rewire something in the guitar, replace a pickup, etc? This almost sounds as if somehow the shield conductor got connected to the "hot" side (center conductor)

You might go through your cables. If the plug shell can be unscrewed (not molded) make sure the shield is actually connected to the sleeve on both ends. Make sure the guitar is wired appropirately. I spose it's very possible for a pickup to be defective, and either have the hot lead shorted to the metallic parts of the pickup, or mis-wired that way