I bought a PCB that will replace the the dip 8 op amps in my Philips CD880 with an SRPP tube amplifier. The transformer and tube amp board will be mounted in an outboard chassis. The board holds it's own power supply and outputs left and right analogue signals to my preamp. Do I need to connect the ground in my CD player to the ground on the PCB? Neither the CD player or tube PCB connects to earth ground.