Marantz CD63 & CD67 mods list

Thanks Ricardo

Here are the main points for the pcb

Size wise it is 69 x 20mm on 1.5mm pcb screen printed
The solder points are gold.
Reversable for either +v or -v voltages
You can use axial diodes or TO220 packages
Panasonic 25V 4700uF FC fits perfectly (or 2x smaller cap)
Optimised length so a 30mm diameter (Mundorf) can be fitted.
Space for 78xx 79xx reg (or spower lol)
option for output cap and ceramics either side of reg
and 2x mounting holes

Brent
 
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rowemeister said:
No problem at all

Hi Brent

Just installed the +-15v spowers on a small pcb ...

The +15v outputs +15.05v...ok
The -15v outputs -15.19v... is this ok ?

I will keep the 220uF BG 16v on the opamps...:devilr:

Note:
The first time I tried the -15v spower, I was reading
-24.9v ....what should be the cause of this ? (I cleaned the tracks... tried again and now it seems ok... but I wonder... is there an issue ?)

Ricardo
 
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Thomo said:
Sounds like a poor ground connection to me, Ricardo.

Hi Lee

That is what I am searching for now.... I do not want to install everything and then burn the opamps :flame:

I need your oppinion; I am considering a 220uF BG on C509 decoder analog and a 470uFBG on C512 Decoder digital.

I can not invert this selection due to the lack of space around C509..... Is this ok ?

Actually I am using 2200uF 6.3v Ruby MCZ on both locations.

Note:
I need some Mundorfs.!!! (You have mail)

Regards

Ricardo
 
RCruz said:

Hi Lee


Note:
I need some Mundorfs.!!! (You have mail)

Regards

Ricardo


Hehe, so have you!

I always recommend smaller value caps for digital rails, this has been discussed in the thread before (if you can find it, hehe). The current draw for the decoder is very low, so I have used 47uF BG Nx, as I always find these give the best sound on digital rails.

What cap do you have on Servo Analog? If nothing special, I would use the 470uF BG there.

Lee.
 
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Thomo said:



Hehe, so have you!

I always recommend smaller value caps for digital rails, this has been discussed in the thread before (if you can find it, hehe). The current draw for the decoder is very low, so I have used 47uF BG Nx, as I always find these give the best sound on digital rails.

What cap do you have on Servo Analog? If nothing special, I would use the 470uF BG there.

Lee

I have got a srayreg (with dedicated psu) and a 220uFBG on Servo Analog.

Maybe I could do the following:

150uF 16v OsCon SH on decoder digital (C512)
470uF BG STD on decoder analog (C509)
220uF BG STD on HF amp (C504)

These are the actually available caps.

Should I wait and use the 47uF BG Nx ?

Note: Thank you for the email.. it was hidden in the "unknown" folder because it´s new.

Regards

Ricardo
 
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rowemeister said:
Hi Ricardo

The -15.19V is fine. The 24V however is as Lee says a missing or poor ground! Luckily the opamps can handle this voltage if it happens again.

Hi Brent

Something went wrong and I inadvertently fed the -15 spower with inverted polarity.... +25v on input instead of -25v.

Something smoked a little bit :bawling:

Now everytime I power on the bench psu (correct polarity now), the spower outputs -15.19v ....but when I shut the psu down, the voltage rises to -15.8 before it starts to go down....

If I switch on while the value is -15.8, it stabilizes in -15.3.... and does not drop to -15.19

Does this mean I severely damaged the spower?

Ricardo
 
analog filter revisited

Just an idea, how about combining Mauro's mod with Bessel arrangement ? Check following

220pF between LO-LON
notch:
C605 440pF -> 2x220pF
L601 470uF
R605=R611 = 16,9kOhm

gives almost constant group delay (max delta about 0.04us according to switcher CAD)

little less than -1,5dB at 20kHz
-98dB at 352kHz = 8xfs with at least -72dB on its harmonics.

Anyone tried that ? I've been just playing with switcher cad :)
Greetings,
Pawel