Which CD player to connect to a luxman LV109

Hi, looking to replace a luxman CD109 (cd player) connected through its digital output to an LV109. Tried a Harman/Kardon HD710 for few years, but did not obtain same quality i had with the luxman. Was it just an impression as the digital output is driving through the LV109 anyway. Don't know at all which way to go, whether any cd player with a digital output will provide same results technically. (can you provide choices) Is it worth investing in marantz SA-8004 to gain back this quality of sound? Thanks,