Marantz CD63 & CD67 mods list

[6h5c]

After modding a Marantz CD63 and a CD67OSE I decided to make a list of all the various mod's I found here and elsewhere on the internet.
I'd like to donate my files to this forum, for all to enjoy!

Of course I do not pretend this list to be complete.
This is all I've done to the players so far and more good tips are welcome!

Greetings,

Ray.

[6h5c]

Here's number two:

[navin]

Originally posted by 6h5c
After modding a Marantz CD63 and a CD67OSE I decided to make a list of all the various mod's I found here and elsewhere on the internet..

will these work on a CD63 KI?

[6h5c]

Originally posted by navin


will these work on a CD63 KI?

Hello Navin,

The differences between the CD63 and the -KI are mainly mechanical, and the KI has a toroidal transformer.
The CD63KI uses the same PCB as far as I know, so the tweaks apply to the KI also. It's possible that a few components (like caps) have a bigger value already, but you can replace them with better low-ESR types.

Regards,

Ray.

[Fidelity Audio]

I have done similar mods, more in some areas but I have not touched the HF amp caps or the HDAM.

Q: What benefit have you gained from this?

Q: What difference do you hear bypassing the HDAM?

I do recommend you fit a clock. This player loves a good clock.

Also Supply the DAC and Decoder with a dedicated REG so that they are seperate from the rest of the noisey circuit, you will be suprised how well this works.

I have changed all the resistors around the op amp to 0.1% tol type + silver mica caps.

I will have to post my 63KI mods too!

[SimontY]

Originally posted by 6h5c
I'd like to donate my files to this forum, for all to enjoy!

Thank you very much for sharing this fantastic list of modifications.

I too have a CD63ki and I have used an Audiocom clock with a dedicated external supply, I installed new op-amps (OPA627bp), and have changed or removed dozens of other components (eg. removed muting transistors and dc blocking caps). The sound is very good.

I have yet to play with the regulators, but this is something I'll look at soon. Also, I have not touched the HDAM, yet.

From your PDF:
"the HDAM-circuit looks nice, but when moving up to better opamps and interconnects this circuit starts to
interfere and degrades sound quality. To disable HDAM: remove R651...654 (+/- 12V), R617/618 and
RH23/24. Insert wire jumper at R619/620."

I have good op-amps and interconnects etc., so it is time to try this mod. Without having the service manual in front of me, I cannot picture how your changes bypass the HDAM - does the wire jumper from R619/20 bypass the whole circuit, if so where does it connect, at the phono sockets?

I second Brent's question about how it affects sound quality.

Thanks and regards

[Fidelity Audio]

SIMON.

The four resistors R651 - 654 supply the two HDAM circuits with +/- 12V.

R617 and 618 are the audio input resistors, these need removing to stop audio entering the HDAM.

RH23 and 24 are the output resistors from the HDAM, removing these prevents audio going backwards into the HDAM.

Resistors R619/620 bypass the whole HDAM (like in the CD43/53)

[SimontY]

Originally posted by rowemeister
The four resistors R651 - 654 supply the two HDAM circuits with +/- 12V.

Ok, nice. Better lift those then.

Originally posted by rowemeister
R617 and 618 are the audio input resistors, these need removing to stop audio entering the HDAM.

Fantastic, yoink they'll go!

Originally posted by rowemeister
RH23 and 24 are the output resistors from the HDAM, removing these prevents audio going backwards into the HDAM.

Splendid, a similar fate awaits said carbon devices.

Originally posted by rowemeister
Resistors R619/620 bypass the whole HDAM (like in the CD43/53)

This was the part I understood less well - how can there exist resistors that bypass it when it's not meant to be bypassed in this player? Are these just not connected normally then? Just unused spaces?

I may even pop the hood this evening and have a tinker. I'll probably break it

Cheers for explaining what the bits do.

[Fidelity Audio]

The bypass resistors are not fitted on the CD63/SE/KI.

They are fitted to the CD43/53

[SimontY]

Originally posted by rowemeister
The bypass resistors are not fitted on the CD63/SE/KI.

They are fitted to the CD43/53

Right then, so it finally makes sense to my tiny mind, cheers