Marantz CD63 & CD67 mods list

[Fidelity Audio]

C501/502/505/507 silvered mica
C504 to 16V 220uF Silmic
R501/502/504/506/507/509 to 0.1% Tol welwyn

[SimontY]

Originally posted by poynton
Most women do sound better in another room!

Oh my, that's a cracker

[6h5c]

Originally posted by poynton
Hi Ray,

The Vref does not need to be exactly 2.5v ( I think ) but it does need to be 'clean'. These are in effect audio amps....... what effect does the psu line noise have on performance??? Cleaning it up cannot do any harm!

I agree, the actual value of the 2.5V is not that critical, as long as it's stable and clean. It will give the drivers a nice solid reference.

Pins 17, 21, 22, 26 supply the output amplifiers so could be considered analog. I think the optimum solution is to power the DAC from 3 independant 5v supplies, clock, digital & analog. Well, thats my plan!

Sounds like a healthy idea to me, separate regulators for every part. At least you'll be sure the noise is as low as possible.

The supply to the servo chip is 5v analog to pin12.
VRef is taken from the feed to pin28, digital supply!

Andy

Hmm, looks like there's room for improvement. I investigated the tracks, and it looks like the schematic doesn't match the PCB. In my player Vref is connected directly to +5V, and not through R122. Also the +5V for the drivers that is supposed to run through R122, via pin 28, is connected directly. But I think this is a good thing, the digital supply has it's own separate RC filter now.

Regards,

Ray.

[Fidelity Audio]

Is there any good evidence of fitting blue/green led's inside the player (level with disc) as a way of improving things.

I have read about lots of gimicks but wondered if there is any truth in it. I understand a blue green light will have some affect on the red light of the laser but how much?

[poynton]

Originally posted by rowemeister
Is there any good evidence of fitting blue/green led's inside the player (level with disc) as a way of improving things.

I have read about lots of gimicks but wondered if there is any truth in it. I understand a blue green light will have some affect on the red light of the laser but how much?

Y B Blue - how blue LED improves the CD playback


Andy

[Franz G]

Ray:

No, I dont use some muting devices at the output, but I should

What I mean: there is some nasty noise, switching the player on and off. And some minor noise, while positioning the head.

I plan to insert relays, like you did.

I have heard this before!

However, I, like many others no doubt, recognise that the pcb layout etc is done by a router with little regard for the sonic benefits of good grounding etc.

However, we do not possess the knowledge or tools to analise and then reconfigure the pcb.

Have you modified your Ground???
If so, please pass on the information.

Yes, I modified the ground, following the recommendations from Gerald Gessner.

Thats why I cannot publish them. But here are many people involved and I am shure: you they will find good modifications for the grounding layout. Just let things happen...

Another hint (the last one): sometimes simple zener diode solutions can be the best and simplest (pin 21/22 of the DAC).

Happy ears!
Franz

P.S.
Ray: yes, nice speakers! I got them cheap some weeks ago. But I had to refoam the woofers (did it the first time). It was a ACR kit from 1988, a four way system (me as fullrange freak...)

[Fidelity Audio]

Poynton... cheers

[avr300]

Have been doing a few things. I have the one 63 as ref. and the other as mod. platform. And a 63SE as second ref.

I did the clock hack first. http://www.acoustica.org.uk/t/63/63hacks.html. Didn't impress me. The sound became "nicer" but less "live". I would say less music and more HiFi. More like the SE, but still less PRaT. Didn't like it, undid it again.

Then I bypassed the HDAM's (still with the 2140D sitting in) together with the DC blocking caps and removed the muting transistors. NOW it became more "live" - more PRaT. I still like what I'm hearing now.

Now I wonder, when I did the clock hack I simply re-arranged the 2 caps CD02 and CD03 and did the ground bounce hack. _AND_ I did this:

"Knock yourself out. Whilst you have the player apart, find link U200 on top of the board - this feeds +5v (at c.2mA) to the SM5872 onboard analogue output stage. Tin the link, cut it then connect the RHS next to CD15 (as you look on the player from the front panel) to your new +5V supply as added above. Now the DAC has separate analogue and digital feeds, lowering noise feedthrough."

Can anyone confirm feeding of the "analog" part of the DAC together with the clock power is a good idea?

/avr300

[Fidelity Audio]

I did all mine seperate. 1 reg for digital ,1 for analogue and 1 for dac clock ref.

I also used U200

[6h5c]

Originally posted by Franz G
Ray:

No, I dont use some muting devices at the output, but I should

What I mean: there is some nasty noise, switching the player on and off. And some minor noise, while positioning the head.

Franz

Hi Franz,

Thanks for the tips. I will try the passive filter with the first opamps still in place, and the secret zener mod. See how that sounds. I think I have an idea of what you mean.

The noise at the output I was talking about is present when the player is in stop mode. If you have no muting circuit installed you should be able to measure it. Could you see if it is present with your player? If not, your analog stage must be the solution !!

Regards,

Ray.