Marantz CD63 & CD67 mods list

[reddish75]

hi i know this is a bit off topic at the moment, but ive been lurking in the background whilst deciding on how to mod my cd67 which a got for a great price 12 pounds in full working order just a little rust on the back plate which was taken care of with white spirit and a lot of elbow greace.

anyway my question is that i want to build a completly separate power supply for it how many trannys will i need at what voltage out do they need to be and waht va rating would you recommend

any help would be greatly appreciated

[poynton]

Simon, where are you ???

[SimontY]

Originally posted by poynton
Simon, where are you ???

Err, here, lol

[SimontY]

Originally posted by reddish75
anyway my question is that i want to build a completly separate power supply for it how many trannys will i need at what voltage out do they need to be and waht va rating would you recommend

any help would be greatly appreciated

Hi,

I'm heading in this direction too. So far I have the following:

Transformer #1: clock supplies
winding #1: 'superclock' feed
winding #2: servo clock divider feed (not needed in CD67)

Transformer #2: digital supplies
winding #1: DAC and decoder digital pins
winding #2: DAC clock reference pin

Transformer #3: analogue supplies
winding 1 (centre-tapped tx.): DAC and decoder analogue

That is the situation at the moment. It sounds superb. I will be adding a further transformer (number 4) just for the servo (one winding analogue, one digital).

The internal transformer will keep powering the op-amps in mine (it's a KI so has a good transformer).

You might like to use a separate, dedicated power supply with it's own transformer for the +/-12v.

Every voltage rail used for audio (every one bar the logic chip basically) should be fed by a low noise regulator. This will allow the full, sweet, natural detail to come through. The sound will not be digital in the slightest. You'll need the other mods too of course (reclocking, op-amps etc.)

To go external you'll need an "umbelical" cord to connect things up. I can recommend the use of DIN plugs. Get nice ones of course. If you want to go mental why not use one cable for analogue psus, and a second for digital? This will be easier to solder up too, if that's an issue.

Simon

[SimontY]

As for VA and voltages, just make the voltages sensible and the VA macho-high. It's generally considered that high VA transformers sound better.

Most of the voltage rails are 5v - dac, decoder, servo. So for these I'd recommend transformers that will provide roughly 10vac or a touch under. This will provide plenty of headroom for regulators to work with.

For the 12v + and - you will obviously need a slightly higher voltage, like 17vac.

Just bear in mind you will need about 3 volts minimum overhead for the regulators to regulate properly. And most regulators will take 30 to 35 volts input.

Use schottky or HEXFRED diodes.

Simon

[SimontY]

Another thing to bear in mind is the transformer type. It is often said the best sounding are R-core. If you have the cash to splash give them a whirl! If on a tight budget you could use E/I core for the digital, as less high frequency noise passes through than with a toroid. Also some people are generally against toroids for hi-fi, saying they sound lifeless and clinical. Don't use old E/I cores unless you don't mind some mechanical hummmm!

Simon

[imperfectcircle]

Hi guys I got some samples of these ultra low esr capacitors in the mail the other day and I was wondering if they would be any good to use in my cd67. They are 470/16v so they would be a nice size to use for the DAC or opamps. I know I read someplace that ultra low esr isnt always a good thing. What do you guys think?

[Fidelity Audio]

Try them and trust your ears.

Your ears are better than any technical bobbins some nerd on here will come up with. Run them in for a week then swap back and see what you think.

Brent

[SimontY]

Hi,

How about just solder some in around the op-amps? Then see what flavour they give. If you like it add some more elsewhere.

I doubt you can go wrong with the ones for digital supplies.

Simon

edit: yeh, just try em!

[dantwomey]

Originally posted by SimontY
Another thing to bear in mind is the transformer type. It is often said the best sounding are R-core. If you have the cash to splash give them a whirl! If on a tight budget you could use E/I core for the digital, as less high frequency noise passes through than with a toroid. Also some people are generally against toroids for hi-fi, saying they sound lifeless and clinical. Don't use old E/I cores unless you don't mind some mechanical hummmm!

Simon

Here's a helpful link to some R-core transfomers.

Regards,
Dan