Marantz CD 67 Mk II power supply

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi guys,

I recently purchased a CD67 mk2 OSE, which is now working fine. With one exception: the power supply buzzes / hums quite a bit. Actually I find it quite annoying, so I want to replace it.

I've been thinking about buying a faulty CD 43, 53, 63, 67 or some such player, as I think it will probably have the same power supply.

But I may also buy a new (toroidal) supply, which shouldn't cost too much. I have the service manual for the 43-53-63, which has the very useful component description: Power Supply. This does not help me at all.

Does anyone know what the secondary voltage should be for this supply? I'm a complete beginner when it comes to power supplies. I've been looking around on the web, but haven't found anything useful yet.

Does anyone have any suggestions for a power supply?

Best regards,

Berend
 
Hi Sarion,

The problem is related to noisy laminates of your power transformer. It is easily fixable with a bit of ARALDITE or similar glue, which you put on the laminates (a lot of it!) and leave for a day or so.

Transformers for Marantz CD player models differ in the amount of laminates, and in type of the copper used (which I doubt!). CD 63 SE and 67 SE use more laminates than plain CD 63 and 67. According to some reviews, SE versions also use OFC (??). I have modified both 63, and 63SE and the only difference is in the amount of laminates; 63 has less than 63SE.

In both 63 and 63SE I used separate torodial transformer for analogue stage only. CD 63 benefited more from this modification, than 63SE. Therefire, I do not suggest transformer replacement on SE models. 63 and 67 are very similar, 67 uses digital servo - analogue stage is the same.

Try the glue. If you still want to replace the transformer, I'll send you a circuit diagram.

Regards,
Nick
 
Hi Nick!

Thanks for your reply. I'm glad it should be possible to fix it! I've attached a picture of my transformer. Do I just put the glue on the blue wrapping in the middle? Or should I do minor surgery and cut away the wrapping?

Also, as you can see in the picture, the left part of the transformer has a transparent plastic cap on it. I've seen this on the TNT website also, where they made a picture of the 67SE. Why is this plastic there? And why not on the right? Do you know?

Anyway, thanks again!

Best regards,

Berend
 

Attachments

  • transformer.jpg
    transformer.jpg
    37.7 KB · Views: 557
After a little more research on the internet looking for "transformer" "humming" and "glue" I came up with this:

"LC
Dear Andrew,
the noise comes - almost certainly - from the power transformer. Here is what you can do:

-Reverse the polarity, that is rotate the plug of 180 degrees into the socket :)
-Install a mains filter like the inexpensive one we suggest
-Insert large soft rubber washers between the power transformer and the chassis, then tighten the screws again.
-It all this fails, ask your dealer or the Marantz service to replace the power transformer."

Well I'll try some of these suggestion too, I have a mains filter at home, and the player is now somewhere else, so it might benefit from a filter...

Nick, can the transformer be unscrewed from the circuit board, so I can put rubber washers under it?
 
Hi Sarion,


The half of the transformer protected with the plastic is the PRIMARY half - to prevent any punctuations and contact with 240 (or is it 220V AC ?). Do not touch this half!!!!! DO NOT remove any tape!!!

You should put the glue over iron laminates - basically EVERYWHERE! Try to tighten 4 copper-like screws, and two black screws (underneath) that hold the transformer on the main PCB. You could remove the transformer off the main PCB, and dip it in to glue - this would be the best. The heat dissipated from the primary winding is not huge, therefore do not worry about overheating the transformer after the glue-treatement. The heat and vibrations come from the laminates interactions!!!

The noise comes from the loose laminates, or the windings with the former are vibrating around the laminates! Put a lot of glue, and leave it OFF for two days.

Mains filters and rubber washers will not help.

Regards,Nick
 
Hi everyone!

Wow, it's been a while! After moving house several times, I found this CD player playing just fine again. Must have been a loose connection, or something!

So now it's time to fix the transformer hum! I want to glue the laminates so as to keep them from moving, which I believe is the cause of the hum (see above).

Nick advised me not to remove any tape. But as you can see in the picture (above), the blue tape (on which the white sticker is placed) covers the laminates. If I put the glue on top of the tape I don`t think it will have any effect, as it won`t touch the filaments, or get in between them.

Can I remove the tape? What negative effect would this give?

Thanks for your help!

Regards,

Berend
 
Berend,

Take out the complete main board with transformer by unscrewing all 7 screws. Gently pull out the two connectors (hold them by the side). Release the brace on the short ribbon cable (hold it between thump and pointer, and slowly pull). Take out the small ribbon. With both hands pull out the larger ribbon cable.

Get the iron hot and remove old solder on the pins of the transformer. Take it out.
If you have some left over varnish for wooden floors just soak the transformer completely in it. Be sure the varnish dries out hard. Don't use the sticky stuf for paintings.

Let it leak and dry on a newspaper. Depending on the varnish it will take two days to a week to harden.

If you are unsure which part belongs where, take pictures before you begin.

Good luck!

Jaap
 
Thanks, Jaap!

I would like to stay away from the soldering iron for this one. I`ve replaced some lasers now and then, but I`m really not that much of a tinkerer :smash:

In your opinion, would it help if I stripped the tape off, turned the player on its side, poured some glue on one side of the transformer (between the laminates) and let it dry? (of course doing all sides, not just one)

I also do not have any varnish around. Would 2-component Bison kombi metal work?

Thanks a million!

Berend
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.