Nubie Modder please advise

[64delux]

Hi,
All I am in the hunt for a CDP to play Mods with just for the experience.
I have been offered a
Philips cdp 634 I searched for its DAc on a DAC list but came up with
PHILIPS CD634 SAA7321 CDM-4/19
Isnt SAA7321 a Filter not a DAC?
Please advise sorry if my questions are naive but I am a nubie and need to start somewhere
I also have been offers a Sony cdp 991.
I would like some advice on these two players as candidates for Begginer modding. are they good candidated or should I look fotr a Marantz as there are so many documented mods there?
Perhaps I should look for a TDA 1541 chip CDP?
I was hoping the Philips above was one?
I have also read that a CM$ or ( is a good transport to look for?
I dont wish to spend lots $$ as I am learning . I would like to upgrade OPMs and clock to start with and look at dampening.
Any help suggestions information gratefully received.
Regards Mitchell

[Mooly]

Why not have a play with both

Swapping opamps IMO gives the greatest obvious difference, particularly if they use the NE5532 as standard.

Clock mods are not always straightforward... although great in theory the problem is delivering the new clock signal cleanly to its destination. If you have a board connected via long leads or not correctly grounded you may well end up worse off.