Marantz CD63 & CD67 mods list

[Fidelity Audio]

Originally posted by philpoole


Simon, if you use the rail that feeds the originally 5v reg than it should be less than 20vdc (I can't remember the exact figure). Using a lower voltage should make the job of the regulator easier - but it should be a bit higher than 5v so the reg works properly.
The regulator would get hotter otherwise, wasting current.

Cheers,
Phil

Its best to use the AC from the TX ans use seperate diodes for supplying the regs. This way you are isolating the DC from other DC.
It also makes it easier when you want to stick an extra TX in there.

Brent

[mickie]

Hello again,
... i could use some advice at the following: I recently replaced the mentioned resistors with the chokes in my cd67 which unforunately gave me a blurry, softened, kind of smeared sound with a lack of dynamics and precision.....
Any of you experienced something like that?
Maybe i should just shorten some of them (R613-616; RD 01,04)?
Or moving up to better resistors....?

Regards,

mickie

[SimontY]

Originally posted by mickie
Hello again,
... i could use some advice at the following: I recently replaced the mentioned resistors with the chokes in my cd67 which unforunately gave me a blurry, softened, kind of smeared sound with a lack of dynamics and precision.....
Any of you experienced something like that?
Maybe i should just shorten some of them (R613-616; RD 01,04)?
Or moving up to better resistors....?

Regards,

mickie

Oops, that sounds bad! Do you know the dc resistance of the chokes used?

[mickie]

yes, they are supposed to be 3,3 ohm (as recommended in the list) but measured 2,6 ohm.

mickie

[SimontY]

Ok, I'm out of good ideas, now someone who knows...

Perhaps the changes you heard are due to improving quality, and you have simply exposed a problem elsewhere. This isn't unknown in hi-fi.

What else have you done to your Marantz?

[philpoole]

What inductance are these chokes? Maybe they're too high and upsetting the HF response? I would of thought they would ahve to be massive to do that though!

Cheers,
Phil

[SimontY]

Yeh, to have that DCR and high L they'd surely be whoppers.

[mickie]

Thanks,
the chokes also supposed to be 220uH; i did about 70% of the mods by now using blackgates all over; maybe there is too much HF-suppression now? The Ferrites...?

I'd like to try shortening the resistors (some guy recommended that; http://www.audioasylum.com/audio/twe...ages/6498.html )

Can i damage something doing this?

mickie

[SimontY]

I've seen that before, I noticed this:

RESISTOR FOR LASER ON:
R136 JUMPER

Anyone done that?

I'm sorry Mickie but I don't know what your problem is. Maybe you just need to let the player settle, for a few hours or more. I know I can get shot down for this but I find after being messed with it takes a little while of being on for the full sound quality to be heard.

[Fidelity Audio]

Mickie

Do you still have the one 5v reg?

What you need to do is ditch the inductors and go for seperate 5v rails.
This way you eliminate one circuit polluting the other and getting much better sound quality (brighter more open better channel seperation etc etc).

Also having a direct 5v supply to ic inputs will give you full current supply. No nasty resistors or inductors in the way.

Don't waste anymore time doing this mate.

Brent