Marantz CD63 & CD67 mods list

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#9,681
Re: Ray's Discrete Output Stage

rowemeister said:


The problems you are finding with your sound are 15% down to having no clock and 60% due to the regs you are using/not using. You really do need to fit a SPower or Audiocom type reg. The difference is night and day. The other 25% is down to requiring more psu 😉 .

But first to try add the sreg onto the dac ana and yes feed it from the +10/12v from before the standard 5v reg.
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Hi Brent

Can I use the analog windings of the stock TX to feed the sreg I am going to put on dac analog ?

Please read my previous post.

Regards

Ricardo
 
#9,684
Thomo said:
Ricardo, I can't see any problems with doing that. It's best to make sure that the headphone circuit isn't still being supplied by that winding though.
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Lee
I already disabled the headphones amp.

rowemeister said:
Try using U306 and U309 for your two points. Measure between these points for ac volts
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Brent

This was exactly what I was thinking about.... I have 17.5v there.

Can I use it (after rectifying and smoothing) to feed one +5v Spower for the analog dac ?

U309 links directly to the dgnd star....:devilr:

After thinking a lot about dividing agnd from dgnd this seems a bit odd... I will feed the sreg from a psu that grounds to dgnd..😱

Ricardo
 
#9,688
avr300 said:


It means no gain achieved. If you psu on any analog still referees to dgnd, then don't use your time on it, you won't archive anything. Do a 100% separation or save your energy.
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That´s what I was afraid of.:xeye:

I will be using it while I do not build a separated psu for the sreg on analog dac.

I recently implemented a star gnd where I fixed the gnd of the dedicated psu I built for the servo´s sregs.

I gained LOADS of bass with this method.... but I did not think about separating agnd from dgnd in this case... So this seems to be much more complicated than I figured.

Should I install two star gnds instead of one ?

Regards

Ricardo
 
#9,691
rowemeister said:
Using 17.6vac = 24.5V dc approx. You can run the reg off this but you may need to put a small heatsink on it because a 20V drop is quite steep. They can run quite hot without an heatsink though.
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Brent
So that might not be a very good idea... too much heat might damage the sreg with time no?

avr300 said:


I would (already have done).
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🙂 Did you separate the servo´s sregs gnd also ?

Would you please describe the sonic improvements ?

Ricardo
 
#9,692
I have a SPower running on 28V dc with a 12V output on a small heatsink. Thats a 16V drop!!! and everything is fine.

It's only the FET thats getting hot, just add a small heatsink if it gets hot. These regs will run quite an high current if on a large heatsink too, I have run one for a few hours @ approx 5amp on a very large heatsink and it worked fine (the FET is specced @ 8A max).

Brent
 
#9,694
rowemeister said:
It's very hard to seperate digital grounds and analogue grounds as some can be linked under the chip itself.

Brent
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Also, there are a lot of conflicting opinions about whether to actually do it at all. Whilst modding my old Marantz (TDA1541), the advice given was to actually link the two gnd's at the dac.

So as always in these modding matters, I reckon the best and most fun part is trying it and finding out for yourself.

Lee.
 
#9,695
Thank you..

I will build a psu for the analog dac sreg based on the stock tx 18v positive winding with schottkys, Pana FC and some polystyrene bypass caps.

The gnd will be as is for the moment.

I believe the spower reg has place to fit a small heatsink...:devilr:

In 10 days I will have enough €€€ to order the spower from sercal.

Today I received an envelope from the Nederlands full of silver wire :lickface:

This weekend will be full of mods.

Life is wonderfull and I am glad I have your respectfull support gentlemen.

Regards

Ricardo
 
#9,700
rowemeister said:
😉 no problem at all
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Hi Brent

After all this weekend was not the best choice for modding.

After replacing c111 - c116 by some silver micas, the player started to skip and then stopped reading disks.

In service mode, I got Err 10 (Radial error).

So I looked for Q106 and it was overheating.

When trying to measure voltage on pin 2, I inadvertedly shunted pins 2 and 3 with the probe....:headshot:

Now everytime I turn the player on, the fuse FH11 burns.

What could be the cause of this issue ?

Can I get a replacement for the Q106 TCA0372 ?

Really need your helpfull input.

Regards

Ricardo
 
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