Monday, January 31, 2011

Modding/Upgrading Marantz CD50

Other mods to this player:
part 1 (this paper)
part 2
part 3
part 4
part 5

A month ago I got hands on one of the Marantz middle lineup cd player - Marantz CD50.
Sure its stock sound is kinda dull although it has one of the best DACs - TDA1541A.

*) UPDATE (06 Feb 2011): Today we made a blind listening test with 2 other guys comparing my moded Marantz CD 50 vs. stock Sony 337ESD vs. Kenwood DP7010
Everyone was surprised - moded Marantz CD 50 outperformed all of the others easily. You cannot image the difference. Even though the Sony sounds very very good, too.

After reading a lot of forums, blog posts etc. on the internet I finally ordered all the components I needed for tuning my player.
- a bunch of Os-con capacitors 330uF/6.3V I found them as the cheapest Os-cons on ebay today
- new LM2940CT-5 regulators 2pcs (will be used later on for special power supply to main digital chips)
- some WIMA MKP 0.47uF
- new op-amps Burr-Brown OPA2604
- and some tantalum capacitors

So I started.

* click on the pictures for better view

1) See my mighty Marantz CD50

2) First I Os-coned the PCB. All major capacitors in the digital and analog part became Sanyo Os-con.
TDA1541A, SAA7220, SAA7310 in the digital part
OPA2604 in the analog part (which will be put in the place of the NE5532)
all of then got Oscons 330uF/6.3V
Yes, 6.3V is okay as all of those chips work with 5V power supply. I will be better if the caps ratings were a little bit higher let's say 16V, but they are almost twice the price of 6.3V, so I decided that these will be fine.

3) It was time to throw again the stock op-amps. They are crap! And put the new OPA2604, which are FET op-amps much much better!

4) Then I added new decoupling capacitors to the TDA's bit pins - 14 x WIMA 0.47uF MKP.
And also bypassed all vital power caps - all new Oscons and capacitors in the main power supply. This simple filter make a huge difference in my opinion.

I also bypassed the main 5V regulator chip (7805 family) with a tantalum 100uF/25V from input leg to ground. This is vital because tantalum capacitors are fast and they put their charge into play exactly when it is most necessary.

5) This time wanted to put into play a NOS mode, too. Non OverSampling. For those who do not know what it is - this is a change in which one of the chips (SAA7220) is being bypassed, because it does oversampling and filtering and thus changes the sound.
And I have to tell you - it's a killer mod! The results are real and you will hear.

- Locate the "LEG 1"/pin 1 on the underside of TDA1541 and SAA7220 chips
- on SAA7220 cut both traces as close as possible to legs 15 and 16
- on TDA1541 cut trace as close as pos on leg 1
- using a thin wire connect the TDA1541 and SAA7220 legs 1 to 1, 2 to 2, and 3 to 3.
- connect the SAA7220 leg 23 to the other chip - the de-modulator chip SAA7210 leg 11.
* In case of the Marantz 40/50/60 - there is a newer chip - the SAA7310 - a square black spider with 44 legs - 11 legs on each side of the square. The mute pin is leg 18 (which looks like floating/not connected)
* In case of the SAA7220 and SAA7210 chips - if the mute trick does not work, you must float (isolate) the leg 11 on SAA7210 before connecting it to SAA7220P 's leg 23.
* for more details look closer into the images, I have put explanations there.

6) Make sure you have put all new elements correct - preserve polarity on the electolite capacitors!

7) Connect the player to power line 220V and be ready to unplug the cable if something smokes or bangs ( if you have connected your new electolite capacitors - Os-cons - with wrong polarity they can explode, but do not worry you will change them again ;-) )

If everything is fine for 10 minutes ... connect to your amplifier and listen.

That's it! Sit back, take a whiskey and have a great time listening to your favourite songs!


  1. Anonymous1:41 PM

    Nice article! I've done some amp modding myself, but nothing that complex.

  2. Thank you!

    Isn't it modding amp more complex? I've always thought that maybe because I haven't done it.

  3. Hi Svilen,
    did you used the Fet-ishizator from Dietmar ?

    You are pleased with it?
    What about the output signal level ? Its enough ?

    Greetings from Bucharest !

  4. Hi Atupi,

    No. For this exact player I have not used Fet-ishizator, but I have experience with it already with another cd players.

    Fet-ishizator with TDA1540 has a little bit lower output signal level, but sings nice.

    The so called power supply of Fet-ishizator is messy and not stable (it does stabilize voltage at all), but if you connect it to a good 12V it will be okay. The so called "gyrator" in the power supply (according to Dietmar) is not doing it's job properly. Even though after a lot of tests and measures I doubt it does any good job at all.
    Also he has put a lot of bypass capacitors which I think are unnecessary. I didn't found any different (by ears and by scope) with of without them.

    I am currently working on a better schematic, e.g. moded Fet-ishizator with less elements and better power supply.

    If you are interested let me know.

  5. I've seen that you reclocked also some cd player. There where some noticeable improvements after reclocking ?

    Now i'm planning after Easter to build an output stage for TDA 1541 based on tubes 6N2P.

    All the best !

  6. Yes, there is improvement after switching to external clock. But this step should be taken after everything else is okay or you may not find so much difference.

    Output stage with 6N2P is great one especially for TDA1541. After that you may try with a new clock and better power supply (dedicated regulator and capacitors' bank) for the -15V of the TDA chip.

  7. Atupi,

    Here are first test of my moded Fet-ishizator and a CS4398 (Vout DAC):

    Happy Holidays!

  8. Congratulations Svilen! Nice mod. Now you must work in power suply lines and in a new clock also. The gain you have with dedicate power regulators may blow your head! And think in tubes not about op-amps in output stage.


  9. Hi Antonio,

    Maybe you have missed the other articles for this mod.
    Yes, you are right that dedicated power regulators are very good move!
    You can read my other post here:

    And of course a new clock installed -

    Now I will try something with tubes, but I am a nubie in tube schematics. Do you have any advice about tubes? Which one I can start with for example.


  10. Hi Svilen:

    Sorry about my hasty comment. You have done a very very good job and you have a true helpful blog. Congratulations!

    For the work you are doing in the Marantz CD50 I suggest you completely remove the SAA7220 chip (you lost the digital out), and therefore redirect the clock signal for the SA7310.

    If possible consider making a dedicated power suply to the -15V/-5V/+5V TDA1541A chip with LM337T/LM317T. It will be a must!

    I have tried some good op-amps biased in class A. They sound nice and I can live with it, but they are not as good as tubes.

    You may try to get some information here:

    King regards,

  11. Hi Antonio,

    I am not sure about removing the SAA7220 chip, because currently it preserves the "mute" function. Or at least I am not sure how to preserve it without the SAA7220.

    I will make a dedicated power supply for the TDA chip. I have a couple of LM337/LM317 in my box.

    And will try with tube output stage with 6N2P.
    Thank you for the link of Lampizator website



  12. Hi again Sliven:

    Its very easy to take the "mute" from SAA7310 and also resend the clock signal. If you want I can send pics about it.

    Best regards,

  13. Hi Antonio,

    I will appreciate if you can send me some details about removing SAA7220 completely and connecting SAA7310 directly.

    You can mail me at: svilensvilencom

    Thank you in advance!

  14. Anonymous11:34 AM

    Nice caps - you have ;)


  15. You can find here detailed explanations for your Marantz to ""remove" the SAA 7220:

  16. I have already did similar mod. Check out the whole article especially step 5. :)

    I have bypassed the SAA7220. ;-)

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  18. Hi Svilen :)
    I found your site while looking for how to do the NOS. I have a mint condition Marantz CD50. I bought a NOS one on ebay a few year ago, so this time I wanted to it myself.

    I am using all Elna SilmicII ( even where the ES are) and a Elna Tonerex 6800u 50v capacitor. Since it is large, i have to bring the wire to the capacitor. What wire do you use ? I have 20awg solid core tin copper wire i could use, is rated 300v or use my 22awg multi-strand silver plated copper wire 600v.

    I am using Wima MKS bypass capacitor as they were very cheap at farnell. LM4562HA tin can opamp and furtech rca socket :)


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