Marantz CD63 & CD67 mods list

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poynton

poynton

Member
Joined 2005
If the hiss is only present when the DAC is connected, it is obviously coming from the Dac! (brilliant deduction, I know)

It could be an imbalance in the filter section or even in the amp itself.

More likely causes could be bad DAC chip, either in the dac or the output section., or poor regulators/ bypass caps around the dac.

Andy
 
RCruz

RCruz

Member
Joined 2006
Paid Member
Hi

I am now tghinking about replacing the Analog 12v TX.

Can you suggest a model that fits inside the CD53 ?

I am not sure about using a 80VS or a 30VA 2x18v from farnell (9531831) / (9531742), but both seem to be too big (Diameter 96.7mm / 81.5mm).

As the difference is so small, I think I will use one 80VA in a outside box... But it would be better to do it Brent style.

Please advise.

Ricardo
 
Thomo

Thomo

Member
Joined 2006
avr300 said:
was the hiss present with the opamp filter ?
Click to expand...


No, it sounded fantastic with the opamps. Could they have filtered out the hiss?

The caps around the dac are Rubycon ZA and Black Gate nx & std. Regs on the dac are lm317 raygulator for dig and Brent's S-Power for analogue, fed by their own windings off a 30va tx.

I will try the output stage in my test player and report back.

Lee.
 
RCruz

RCruz

Member
Joined 2006
Paid Member
RCruz said:

I will measure the output of the amplifier without the speakers connected and let you know the results.
Click to expand...

Hi Andy

I measured the offset in the power amp output without the speakers connected and it is 0.13V (129mV).

As it happened before I removed the output caps, I tried the radio and even with the volume pot set to zero, there is always the same offset.

Is this normal ?

Ricardo
 
A

Andre Visser

Member
Joined 2007
RCruz said:


Hi Andy

I measured the offset in the power amp output without the speakers connected and it is 0.13V (129mV).

As it happened before I removed the output caps, I tried the radio and even with the volume pot set to zero, there is always the same offset.

Is this normal ?

Ricardo
Click to expand...

Hi Ricardo

The offset is a bit high (it should not damage anything though). If you get the same offset with or without the output caps on the CD then I would say its save to remove them. What offset do you get with the amp input open?

André
 
RCruz

RCruz

Member
Joined 2006
Paid Member
Andre Visser said:

The offset is a bit high (it should not damage anything though). If you get the same offset with or without the output caps on the CD then I would say its save to remove them. What offset do you get with the amp input open?
Click to expand...

The same.... -129mV left chanel and +129mV right chanel , with or without signal :hot:

I always felt the Meridian topology to be strange...

Just removed the output caps and there is no difference in this offset.

This made a BIG difference.

The sound is now open and with a low bass with detail.

Thank you for your help.

PS

Can you suggest a TX for the analog PSU ?

Regards

Ricardo
 
RCruz

RCruz

Member
Joined 2006
Paid Member
Andre Visser said:
I believe the 2 x 18V, 30VA with good capacitors is more than enough. Good to hear about your sound improvement.
Click to expand...

Hi André

Can you help me choose between Nuvotem 0030P1-2-018 (toroidal,estructura abierta,30VA,0-230V primario,50/60Hz,2x0-18V secundario) and Nuvotem 91231 P2S2 (toroidal,30VA 115/230V primario,50/60Hz,2x0-18V secundario).

Both are available on RS.

The difference seems to be the primary windings but what should be the best option.

I have 220V mains.

Regards

Ricardo
 
Thomo

Thomo

Member
Joined 2006
SimontY said:


Fantastic Lee! Sounds natural, doesn't it? Will this ultimately go in yout main / KI machine?

Simon
Click to expand...


Hell Yes! In fact I am just about to start fitting all the power supplies now.

My cd67 has been in the drying out clinic, after a vase of flowers smashed into it with the lid off. It appears rather poorly now, so I am changing to a cd63 which I was going to sell, but now I can't.

Lee.
 
J

jimh0612

Member
Joined 2006
Where are you Brent??

Just been catching up on the thread and I've noticed that one of the main contributors is conspicuous by his absence.

Is it coincidental that the absence started round about the same time as some (I consider to be unfair) criticism?

I for one hope not.

Brent has always been more than willing to help (as have Ray and others, I hasten to add!!) and has got me out of more than one self-inflicted ham-fisted sticky situation.

So what if Brent has decided to branch out and add mods to his existing company portfolio of test equipment?

He has worked damned hard at his research and put an awful lot back into this thread and I say good luck to him.

Come back mate, we miss you!!
 
Pars

Pars

Member
Joined 2004
Mags said:

Brent.

How much do you pay DIYA for advertising?

Why don't you start your own Secal thread on the Trade forum instead of cussing Audiocom and pushing your own products on this thread? I think it would be a lot more productive!

Mags.
Click to expand...
Yes, from what I have seen and read of this thread, I thought that this post was unfair and in poor taste. Brent seems to go out of his way to provide guidance and assitance... certainly not what you would expect of someone "pushing" their own products.
 
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