Project - Marantz CD5400 modding (pics)

[jomar]

Originally posted by iamwhoiam
Latest update:

Finally my output capacitors arrived..



A Polypropylene foil 8uF "Audio Grade" by LCR to replace the Elna Starget 10uF I originally had in there. Thing's huge and had to mount off board.

I refer to the orig output The 10uf Elna Starget caps ... are these the same as the DC blocking caps ?

[zanash]

Don't miss out on replacing the rectfier diodes with something like the 11DQ10's schottky diodes.....penny for penny the best upgrade I've done in the various cdp's I've moded.

[Heph]

Just to say, I missed the line about the AOPs, so my question will be what's the difference between a AD 863 and AD 825???

Also about getting rid off the "Mute", I've got a few questions....
What I would do to get rid of it is to take out the transistors Q404, Q405, Q406 and Q407.
But then the DAC's datasheet says it triggers the "Mute" in case of initialisation, reset and so on... Is there any risk by disconnecting it?
I was also wondering what the Q403 circuit was suppose to do as it also triggers the "Mute" (sorry, it's my first project so I've got some stupide questions... )
The real question is: Is it a good idear to take those four transistors out???

Thanks.

[Ruach]

Take out those transistors. You can desolder the leads and ease them out. You can always put them back in if you do not like the results

[Ruach]

I noticed that there are two transformers within your 5400. What does the smaller tranny do? Just curious

[Heph]

The Small transformer is their to supply the front part during Standby so you can switch the cd on and off from the front panel, it supplies the Relay to switch the main transformer on.

[iamwhoiam]

Have you disconected the headphone amp?

Yup, definitely. Don't want another load in there do we?
Tis a simple jumper to pull out.

But then the DAC's datasheet says it triggers the "Mute" in case of initialisation, reset and so on... Is there any risk by disconnecting it?

No risk of disconnecting the muting caps. But there is sometimes audible noise when the CD player is operating, eg changing between tracks, switched on/off etc. The DAC can turn it's "mute" output high, thus switched on the muting transistors and thus muting the sound.

Those big fat caps could pick up noise from the nearby transformer

I might shield them in some copper foil if i can get my hands on some. Also need to shield the DAC chip

What about changing the AOPs. They are CMS ones so it seems to be a bit tricky but might be interesting. A found some AD825 AOPs CMS size

By AOPs do you mean the low pass filter opamps? These are the opamps that follow the DAC audio output stage. They are not IV stages because the cs4392 dac used is a voltage out dac.

Originally posted by iamwhoiam
Biggest change was replacing the standard NJM2086 opamp with AD8620. The circuit has two NJM2086 dual opamp chips acting as a low pass filter after the DAC stage, so it requires two AD8620s. The supply is +12v/-12v which is just under the AD8620's max voltage of +13v/-13v.

...Already replaced these opamps as you can see from my first post

I refer to the orig output The 10uf Elna Starget caps ... are these the same as the DC blocking caps ?

If you mean are they the coupling capacitors for the output stage of the low pass filter, then yes

I'd recommend to put BlackGate N-types in C201, 202, 301 and 302. I'd then recommend some high quality poly-foil caps for C210/310... I can't afford blackgates

Don't miss out on replacing the rectfier diodes with something like the 11DQ10's schottky diodes.....penny for penny the best upgrade I've done in the various cdp's I've moded.

...

Originally posted by iamwhoiam
Power supply bridge recitifier diodes were replaced with ultra fast types and paralleled with 100pF Wima FKP polypropylene caps. Original Diodes = 1N4002, replacements = UF4002

Already replaced these with UF400x types and bypassed with film caps. These caps suppress any noise generated by the bridge diodes as they switch on and off. Might replace these diodes with super fast BYW98-200/BYW100-200 diodes in the future (25ns reverse recovery time).

[i2k92]

I've started my mod today by removing the muting transistor and changing the power cable to a 3 x 1.5 mm no name cable. Even with this small changes, the improvement is audible. I tested with a CD of John Mc Laughlin-Al Di Meola-Paco de Lucia (three guitar gods) and now I can clearly hear their fret noises and more bass. Not sure if it's the effect of the trans or the cable.
I also remove the connection to the HP amp, but I don't hear any improvement, so I will put them back.
Regarding muting trans, yes there are some audible side effect, normally when you turn on / off the player when the amp is on. I can hear weak "plop" from my speaker. But I can always turn on my amp after the player and turn it off before the player. The other effect is another weak "plop" when I press play after inserting a new CD, but it is very weak and I can live with that considering the improvement I've got.
Tomorrow I'll replacing some capacitors with Elna & Blackgate (very few of them, too expensive).
I will also try to add some LED on the transport are, I got the idea from : http://www.1388.com/articles/pioneer/. They said that Krell have done this too.
I'm not sure to replace the opamp or not as I'm not brave enough to play with SMD component.

[iamwhoiam]

Anymore news on your mods?

Might remove the muting transistors next time I open the player up..

[i2k92]

It takes some time for the Elnas and Blackgate to break-in, I let the player run for several day non stop. My impression is that the sound is warmer now, perhaps that's the effect of the Elna caps.
Today I'll replace the rectifier diode with BYW98-200. I've got these diodes for 1 month, I haven't installed it as the pin is to big for the PCB hole. I'm going to buy a small drill to make the hole bigger.
Next, I've plan to replace the opamp with AD8066. I have to order it from US or Australia, as I can't find it at all in Europe. Then, upgrade the clock with Tentlab's XO module (the clock only, not the XO2/3 board, too expensive) and give it a separate PSU. and offcourse, replace the caps on the digital section.
Anyway, where did you get your ad8620 from ? And what is the result after adding those gigantic caps on your player's PSU ? cause I'd like to have a try