Marantz cd upgrade

[elgee]

Marantz cd upgrade vs modifying

I have a cd6000 ose and a cd52 mk2 se. I am looking to improve the sound quality by either modifying either of my existing players or upgrading to a later model cd6003/4/5 which have had good reviews. Trouble is I don't know which would give me the best hike in SQ for money spent. I've read that the 6000ose is difficult to mod and that the cd63/67 is the best for this and there are certainly a lot of mods published for these.
I seem to have a number of choices but not very much comparative info to go on. If anyone can shed any light on these choices I'd be glad of the input. Although I can't spend a fortune I am keen to get the best sound I can without breaking the bank. Any suggestions most welcome. Thanks.

 

[Andersonix]

I don't know those models, but if they have any op amps then swap those for new ones...

 

[elgee]

Thank you for the suggestion Andersonix. What do you think I should use as replacements? I'll need to check out the model numbers, but assuming there are op amps in there, are there any particular makes/upgrades that you would recommend?

 

[Johno]

LG,
there are very handy step by step photos in this thread
http://www.diyaudio.com/forums/digi...cing-draw-cog-belt-cdm4-19-e-g-cd42-cd52.html

I have also documented the upgrade I did for my own CD52 on that thread - very very happy with the results

 

[Andersonix]

LM4562 is nice and cheap and comes in an 8DIP package.
If there's a 7805 type Vreg for the DAC, you could go with a Murata SR7805 for about $10.

How far do you want to go? Looks like Johno is very ambitious with his mods!

 

[Johno]

The CD52 from the early 90's is now getting quite old. Very much overdue for new electrolytic capacitors, especially in all the power supplies. So there is no point making other changes before you replace the capacitors. All I did was find the largest values in fairly good quality types that would fit on the PCB. Essentially narrow but tall types with 105C temp rating.

Recapping alone made a huge difference to the sound quality.

Using LME49720 (or the LM4562) are my preferred op amps. Recommend you install IC sockets as well, in case you need to swap again.

Using an external temp compensated clock module for the DAC noticeably improves the sound clarity, especially with classical music.

Adding the second power transformer allowed the servo motors to run without voltage droop - increases precision. Also separated the noisy digital stuff from the analogue.

And overall I think the CD52 is the better machine of the 2.

 

[elgee]

Thank you both for the advice. I've already replaced the tray mechanism of the cd52 to good effect - I'll probably give it to my son as the basis for his hi fi setup. I prefer the sound of the cd6000ose so am erring on the side of working on that one. I confess that my electronics experience doesn't amount to much but I can solder & de-solder reasonably well, so I think I'll start with a few straightforward mods like the ones suggested by Andersonix, then move onto the ones Johno mentions. I need to get inside the 6000 to see how it differs from the cd52 and check out which components it uses. Thanks for the suggestions.

 

[Andersonix]

I also consider myself handy enough around a soldering iron, but I still accept the risk of 'bricking' anything I take apart! Most of these plasticky things are not meant to be disassembled too often...

 

[elgee]

Yes I've heard that the Marantz PCB is a bit delicate. Thanks for the warning.