I'm finally installing a set I got last year: NP5F and a NJ5FSb. I have an Audere preamp so I was going to run black to the common and gray to ground. The J has all three wires but the P doesn't. It's black and white only... So I wired the J like the instructions say and put the P's black wire to ground. I'm getting signal from the J but not the P. Any ideas?