am a bit puzzled with all the codes used in Philips pro mechanics.
Which relation exist between them and the sound quality of the final OEM products? In other words for istance, is the CDPRO 2 better than the CDPRO 12 and CDPRO 12.4 ?
Thanks for a sort of ranking when possible.
Also the most famous was the CDM9-PRO (still avaliable?)
The first is a top loader. The 12's and 12.4's use drawers and have had some issues for their age. Philips doesn't make CDP's anymore so supplies are fading but still available. I think Sony dropped out of that business too and went to DVD.
CDM-9 Pro and CD Pro 12 are no longer made. I have never heard of CDPro 12.4.

CD Pro2 is the only "PRO" series transport which is currently beeing made.
I know they all seem to break. Here's something you may be interested in anyway.
Never heard of CDMPro2 breaking. This is one of the most robust mechanisms.

The one that was notorious for breaking is CDM-9Pro.
Of all the parts you mention only the pro 2 is easily available. It's good, one of the best Philips transports modules.
The CDM PRO2 is used in the large jukebox players you see in bars and everywhere else. I also never heard of them breaking. Choice of just about any player with a dedicated cd transport with a toploader which i like vs the drawer, less moving parts.The cdm-1 was an outstanding unit but do not make any longer. This unit is from the highend days of the late 80's and earyly 90's when transports where not made from plastic. This is one reason i looked for the CDM PRO2 for my transport.

The CDM-9 Pro is no longer available and was the finest transport for redbook ever made.
It was used in the famous Krell KPS 20i(one of the 5 best cd players ever made according to trade publications)
The CDM-9 PRO used the smallest error correction circuit of all of them.
The CDM-9 liked a clean disc and could track with incredible ease and let you hear what was there without substituting false info.
The unit was too expensive for Philips to continue to make so they came out with the plastic housed drives and caused an uproar with manufacturers which made many have to discontinue or completely redesign product.
I have a Krell KPS 20I and purchased an extra 9 PRO before they vanished and it is priceless to me, as to this day the unit is still the best sounding unit I have ever heard.
I would suggest much caution in buying any unit that uses a 9-PRO unless the seller could provide you with a back-up 9-PRO,because if it goes than you have nothing but a parts unit for someone like me and NO ONE and I mean NO ONE has any replacement 9 PRO drives anymore.
I am looking to purchase a replacement orange gear that is broken in my Theta Data Basic. Are there any available anywhere?
Best Regards, Rick Larson
If you go to Ebay and click on HOME AUDIO and then type in MARANTZ, scroll thru the pages as there is a person selling a replacement gear that is orange for various players with this transport. Your Theta data basic is mentioned that this gear will fit. This is what the site says;

Newly made in Japan and better material than the China made one.

This is a brand new Tray Gear wheel For Philips CDM9 , CDM9 PRO Tray.CDM9 usually used in CD-players like Meridian, Marantz, rotel, Philips, PS Audio(Lambda, Lambda II), Rotel, Arcam, Theta(data basic,data basic II) .........
Philips CD-930 CD-931 CD-950 CD-951 LHH100 LHH200, Marantz , Aura CD50 CD100