PS Audio GCPH and Pass X0.2 not talking?

I am baffled. My VPI Scoutmaster 'table works. My PS Audio GCPH phono preamp works. My Pass X0.2 preamp works. But when I plug the GCPH into the X0.2...nothing. No sound. No signal. (The lights are all on, but no one seems to be home.) I've quadruple checked everything from cables to inputs, but can't figure out why nothing is coming out of the X0.2 from the GCPH.

What I am doing wrong?