I stumbled on a site by apparently a Polish guy, who is obsessed with making CD players all tube (or valve, for you people on the isles) apart from the DAC, of course. I'm not sure if I agree with all his points, but it sure makes for some interesting reading:
http://www.lampizator.eu/
For the residents of this forum, the ranking page http://www.lampizator.eu/LAMPIZATOR/CD_player_ranking.html might be the most interesting, particularly the story on CD5500 in the end. It never occured to me that this series is one of the very few CD players made that have no pesky integrated amplifiers on the signal path.
He also seems to be a strong advocate of the TDA1541A 