Marantz CD63 & CD67 mods list

wojtek.l · 2006-02-05 2:36 pm

Hi Franz,
Have You additional transformer to analog or digital section?

poynton · 2006-02-05 2:47 pm

6h5c said:
......... The circuit sounds very good, but I have some HF noise present in my tweeters. .....

Or a noisy tube or FET ??

I would also be tempted to play with the values of the 620pf caps ?? The original circuit has more filtering - a passive filter may also be an answer??

Andy

Franz G · 2006-02-05 6:24 pm

Have You additional transformer to analog or digital section?

It's for the analog section.

Franz,

Do you have a schematic of the passive circuit you use?
Is there any noise residue with this passive circuit?

Absolutely no noise, just music!

Gerald Gessner is selling his modifications, so I am not allowed to publish the exactly circuit.

It is really just a LC filter, 1mH in series with the signal, 10 nF to ground.

And: no output cap!

When I use this player with my DC coupled PL519 amp, then I have absolutely no cap in the signal path after the DAC chip.

Franz

Franz G · 2006-02-05 6:30 pm

How close does the tray come to the Tx / board??

Very close: just one or two millimeters left between the tray and the Tx

Franz

poynton · 2006-02-05 8:47 pm

Hi 6h5c,

Sorry - just a couple more questions!

I have just breadboarded my version - not connected to the cd-p yet. Nothing went BANG !!!

Did you use ecc88?
What B+ did you use?
Did you check the current through the FET?
What voltage did you get at the A-K junction.

Andy

Fidelity Audio · 2006-02-06 10:26 am

Morning.

Just a little update on my player.

I used sound deadening material on cdp and amp and I am very impressed with the out come. The bass is deeper and the treble is more controlled, I knew it would help but not this much

I have also changed the 7918 for a 7912 for a dimmer display.

I have now finished my reg pcb fully, I now have an Audiocom super reg for the +5V clock reference on the DAC.

Here is a pic of reg and of pcb......dont know where the tube stage will go. lol

An externally hosted image should be here but it was not working when we last tested it.

SimontY · 2006-02-06 11:52 am

Mmmm, nice mate! :nod:

Fidelity Audio · 2006-02-06 3:22 pm

I have just taken off the bottom plate of the KI and bonded it with Aluminium paste (used to repair gearboxes etc). I wont come off now. lol

I did this has I felt it was not making the best contact across the whole chassis as it could so damping was suffering.

Biskit · 2006-02-06 3:42 pm

Any news on the custom TX.

I'm thinking of potting my frame tranny in a mu metal can.

Gordon

poynton · 2006-02-06 3:45 pm

rowemeister said:
I have just taken off the bottom plate of the KI and bonded it with Aluminium paste (used to repair gearboxes etc). I wont come off now. lol

I did this has I felt it was not making the best contact across the whole chassis as it could so damping was suffering.

Hi.

One thing I noticed, about my '63SE, was that the bottom plate when hit really rattled!!!!!!!!! I suggested, earlier in the thread, that glueing it down was a good idea also a 12mm mdf 'plate' glued to the underside adds to the chassis damping and stiffness.

Andy

SimontY · 2006-02-06 3:47 pm

Biskit said:
Any news on the custom TX.

I'm thinking of potting my frame tranny in a mu metal can.

Gordon

Mu-metal is the dogs for shielding EMI isn't it? Won't you be better off getting this custom toroid though?

Fidelity Audio · 2006-02-06 3:50 pm

Yeah custom or KI tx. Much more headroom

6h5c · 2006-02-06 3:57 pm

poynton said:
Or a noisy tube or FET ??
I would also be tempted to play with the values of the 620pf caps ?? The original circuit has more filtering - a passive filter may also be an answer??

poynton said:
Did you use ecc88?
What B+ did you use?
Did you check the current through the FET?
What voltage did you get at the A-K junction.

Hi Andy!

Well, I know a bit more now. The remaining noise is not coming from a tube or the FET.
I measured in my CD63 to compare the results, and it too has this noise at the output

.
Would you, or somebody else with a scope be so kind to verify this on his player? With the player in stop-mode and no muting circuit and HDAM installed, I can measure allmost 20mVpp.

For Thorstens circuit I used ECC82 on a B+ of about 220V. I didn't have 4k7 around for the PSU series resistor, so I gave each channel a 6k8. I upped the B+ a little so the voltage behind it reaches the desired 190V. The A-K voltage should be about 100V. The voltage over the FET is less than expected, because the DAC's 2,5V DC voltage is divided by the 10k-22k combination. The current through the FET is about 4mA. The FETs are not very equal....

Regards,

Ray.

Fidelity Audio · 2006-02-06 4:06 pm

I have 22mV on outputs with no HDAM

6h5c · 2006-02-06 4:09 pm

Franz G said:
Absolutely no noise, just music!
Gerald Gessner is selling his modifications, so I am not allowed to publish the exactly circuit.
It is really just a LC filter, 1mH in series with the signal, 10 nF to ground.
And: no output cap!
When I use this player with my DC coupled PL519 amp, then I have absolutely no cap in the signal path after the DAC chip.

Franz

Thanks Franz. I think the noise is there, but you'll have to set your volume to max. to hear it. The tubestage's amplification is less, so I noticed it when I turned the volume up.

rowemeister said:
I have 22mV on outputs with no HDAM

Thanks Brent, for measuring so fast :up:

!
Thank goodness i'm not the only one, apparently this is normal for this player.

Regards,

Ray.

Bas Horneman · 2006-02-06 4:12 pm

Hi Ray,

Just popped in to say this is indeed a cool thread...!!! Plenty of co-operation. And a lot of interested people.....gotta get me an old Marantz somewhere..

So is the tube stage all you dreamed of?

Regards,
Bas

6h5c · 2006-02-06 4:15 pm

Bas Horneman said:
Hi Ray,

Just popped in to say this is indeed a cool thread...!!! Plenty of co-operation. And a lot of interested parties.....gotta get me an old Marantz somewhere..

Regards,
Bas

Hi Bas!

Thanks for the compliments! How's your PP project?
I haven't had time yet to put your chokes in my amp, but PSU designer shows it's a good thing. Been busy with this tubestage...
Maybe next week, I'll let you know what the results are.

I've got a CD63 for you, but it's already modded....

Regards,

Ray.

poynton · 2006-02-06 4:16 pm

6h5c said:
Thanks Franz. I think the noise is there, but you'll have to set your volume to max. to hear it. The tubestage's amplification is less, so I noticed it when I turned the volume up.

Thanks Brent, for measuring so fast !
Thank goodness i'm not the only one, apparently this is normal for this player.

Regards,

Ray.

HI.

To find the source of the noise and so reduce / eliminate it, you need to measure earlier preferably just after the dac.

Andy

poynton · 2006-02-06 4:20 pm

Bas Horneman said:
............ co-operation. ..............

After all............

...............Resistance is futile ..............

Bas Horneman · 2006-02-06 4:21 pm

Thanks for the compliments! How's your PP project?

Haven't started yet...maybe tonight :smash:

I haven't had time yet to put your chokes in my amp, but PSU designer shows it's a good thing. Been busy with this tubestage...
Maybe next week, I'll let you know what the results are.

NO hurries mate.

I've got a CD63 for you, but it's already modded....

Thanks...but that would be a waste of a great sounding CD player..since I'll would probably end up using it as a transport for my RAKK DAC.

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