Krell FPB 400CX vs PASS LABS X-350.5

I'm moving up the ladder and have it down to these two amps. Any suggestions?? Should I go with the Krell FPB400CX or the PASS LABS X-350.5??

Speakers: DeVore Fidelity Nines
Preamp: Pass Labs X-1
Source: Esoteric X-03SE
Cables: Audiopath Silver 8 all around