Marantz CD63 & CD67 mods list

[bull041161]

Hi all been a while since i have been on here. Im after some help with my marrantz 67se its had some mods done its had the hdam circuit by passed it as a n external power supply but not sure what it runs i repaced the opamps with the ha screened ones, But it sounds bright and harsh with not much bottom end clout. And just wondered if there was any one in sheffield who could have a look at it and make sure its been done right

[higlander]

Originally Posted by Ben Hanke

Couple of questions for the guys with multiple transformers:

I've asked this before, but do you hear any mains hum in stop mode with the volume maxed? I used to hear just the residual DAC noise, but now there's mains hum mixed in with that. I wonder if I have a 'dirty chassis' (a term I picked up investigating ground problems on audio equipment).

230v guys: If you buy a transformer with 2x115v primaries, how do you parallel the primaries? Do you tend to cut the wires shorter first?

Thanks,

Ben

Hi Ben. I have 3 Txs in my CD63 and I don't have 50Hz hum. When I crank the amp. to full power I can only hear a very slight hizzing sound from the speaker tweeter and there is no hum at all.

for the primary you should connect like this to get 230V:
_________
{
{ 115V
{__________
__________) joint these
{
{ 115V
{__________

You may cut short the middle cables before you join them together and then insulated the connections if you are not going to connect to 115V supply in future.

[higlander]

Originally Posted by bull041161

Hi all been a while since i have been on here. Im after some help with my marrantz 67se its had some mods done its had the hdam circuit by passed it as a n external power supply but not sure what it runs i repaced the opamps with the ha screened ones, But it sounds bright and harsh with not much bottom end clout. And just wondered if there was any one in sheffield who could have a look at it and make sure its been done right

Have you changed the smoothing capacitors to 10,000 - 22,000uF ?

[bull041161]

Originally Posted by higlander

Have you changed the smoothing capacitors to 10,000 - 22,000uF ?

Not sure i have done nothing only changed the opamps as electronics is not one of my strong points lol. I could post a pic of the board some regulaters have been changed and some big caps put on the voltage input but the work looks shabby to me and untidy. Just wondering if the person who did it knew what he was doing

[UV101]

did you take any pictures? Should be easier to see whats been changed so far....

[Ben Hanke]

Thanks for your replies, folks. It seems I have my transformers wired correctly, and all my mains cables are northwest of the original transformer position so unlikely to interfere. I'll double check that the smoothing caps on the analogue rails are soldered properly, then it might be time to think about getting a scope.

[mcd99uk]

Originally Posted by Ben Hanke

then it might be time to think about getting a scope.

I'd say so. A scope, even an old one (mine is an old fluke portable job), is near essential. My CD67 would still be sitting there clicking with the disc spinning in the wrong direction without one.

[Fidelity Audio]

Originally Posted by Ben Hanke

Couple of questions for the guys with multiple transformers:

I've asked this before, but do you hear any mains hum in stop mode with the volume maxed? I used to hear just the residual DAC noise, but now there's mains hum mixed in with that. I wonder if I have a 'dirty chassis' (a term I picked up investigating ground problems on audio equipment).

230v guys: If you buy a transformer with 2x115v primaries, how do you parallel the primaries? Do you tend to cut the wires shorter first?

Thanks,

Ben

Hi Ben

I got some mains hum on mine many years ago and it was because of the location of the analogue stage psu to the transformer. I could not get rid of it. Once I built an external psu for the output stage the hum went away (obviously). Run +/- voltage into the player and direct to your output stage, if you build a good psu you will also get audio improvements.

Also doing this frees up a area for a tx to be used for other circuits

Brent

[bull041161]

Hi all im trying to post a pic of the mods on my player but not sure how to do it can any one helpcd player 008.JPG

cd player 003.JPG

[bull041161]

Ok done it this is whats been done i have only upgraded the opamps rest was done when i bought the player. Detail is not bad but trebble is harsh and bass is not as deep as i would like the midrange is not so good eather. I have had a moded 67se before and i know what thay can sound like but this one does not do it