Help needed with CD player upgrade.

[TB]

Hello, this is my first post on digital forum so please bear with me. I have always wanted to upgrade my CD player, but with limited knowledge, I did not want to experiment on my existing machine. Finally after looking for CD player to play with I was able to buy Mitsubishi DP-107 one. I did try to search the forum about this model, but with no avail. The player is in nice working condition. What cought my attention is very quiet and smooth tray mechanism. The tray opens and closes without any sound. It is hard for me to tell anything about quality of electronics, but transport system is nice. It does not remind cheap CD Rom type. It looks like entire transport is mounted to nicely damped metal plate. PSU consists of EI transformer and four 2200uF Elna capacitors. DAC chip is a PCM 56. The player has only analogue outputs. An internet search brought only one information: this is Yamaha based player. Unfortunately, DAC chip is not socket-mounted, but soldered to the PCB. Would it be possible to upgrade this player? Is PCM 56 good sounding DAC? And...what should be done to make nice sounding machine ?
Thanks for the help !!!!!