Friday, February 17, 2012

Modding/Upgrading Marantz CD50 - part 5

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

Almost a year since my last mods to this Marantz player, yesterday I came up with new ideas about it.

Here's what I decided to do and deep listening test after every mod step by step I confirm here only those that really do change the sound to a even higher level than before.

1) I removed the crappy Nichicon Muse 22uf output capacitors and put perfect Ampohm 4.7uf Polypropillene capacitors directly to the output RCA sockets.
Here you can use every PIO (Paper In Oil), polypropillene, styroflex capacitor with value between 1uf and 10uf.
Please do not use old russian ship container like caps or the small ceramic caps.

2) I had some Blackgates 100uf-470uf/25V and put them everywhere - around DAC, around digital chip, around opamps. They make the best sound for opamps in matter of not distorting the signal in any way. I've tried Nichicon Muse, Elna Silmic II, etc. but they all put some of their taste to the sound and I do not like that. I wanted pure, flat, without distortions capacitors and these are only Blackgates.

3) Variable output board was removed. It uses the +/-15V from the power supply which are used by the TDA1541A DAC and opamps, so this step will relieve a little bit the PSU.

4) For opamps I decided to switch to LM4562HA. They are really good!

5) Before the main 7805 regular in the PSU I decided to put in ~20000uf capacitance.
The rule of thumb says that if you drawn 1A of current you need at least 20000uf capacitance so you can filter perfectly the 50Hz/60Hz noise from the main line.
Here we do not have such currents, although I decided to put 7 x 3000uf caps in parallel forming 21000uf multicap

6) All diodes was change to schottky ones. Schottky are smoother. You have to change all diodes in the played so you can hear a real difference. Changing only one rectifier won't have any effect you can hear.

7) After all regulators (7805, 7806, 7815, 7915) I put 2x the original capacitance tantalum capacitors (yellow ones on the pictures below)

8) I removed all small 100nf ceramic SMD capacitors on TDA1541A's decoupling pins and then I put 0.47uf WIMA. You really have to remove the SMDs first! Believe me!

9) Have you read about DEM clock for TDA1541A? It's time! You should read THIS PDF.
After that just change the capacitor between 16th and 17th pins for 120pf/1% tolerance one and you will be amazed.

Here are some photos during these interventions.

Multicap bank of 7 x 3000uf/16V put before the main 7805 regulator.

0.47uf Wima caps on the 14 decoupling pins of TDA1541A. You see the little blue cap of 120pf for DEM lock.

Upgraded capacitance to 6600uf before 7815 regulator.

View of the whole player with clock, main line AC RFI filter, all Blackgates, big 21000uf caps bank, etc.

The great output Ampohm 4.7uf capacitors.

Some Blackgates.

More Blackgates for the digital filter chip.

Main capacitor bank installed in the player.

AC RFI filter. Very, very important! And costs only 8EUR.

That's it for now!
I am very pleased with my last upgrades to this player.

What's comming:

* +/-15V PSU low noise, low impendace for DAC and opamps
I will try one of these:

*) Please, do not bother saying that it looks awful. I know. It's a test player for different type of mods, so I do not care for the look. I just want to hear if something is worth the effort applying in my primary player and/or some player of a friend.