upgrades to marantz CD6000 OSE

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#61
I have just checked, I have a voltage of about 200mV. Apart from the clicks on starting or stoping the cd I can't hear anything when its playing, and the sound is MUCH better.
So is the DC a problem and if so is there a way of reducing it?

Thanks


James
 
#62
Is the voltage this much off for both channels or just one?

Can you check the voltage on the optional OSE HDAM module contacts (marked TKC-A 1212 on schematic) pins 2,5,8,11

These should all read 0V or +/- 10mV

If this is so the offset comes from the last discrete HDAM module, if not then the already the opamps have DC offset....

Ergo
 
#64
I took the player apart to try and mesure the voltages but I'm afraid my knowledge/skills aren't up to the job as I couldnt find the pins...😕
The DC voltage is about +200 on the Left channel and -130 on the right channel. But apart from the clicks is this a problem?


James
 
#65
If you amplifier is not totally DC coupled then this can not do any harm (very very few are).

You can make sure if you disconnect a speaker cable and put it back while you have an amp input set to CD input. If the speaker cone doesn't move quite stronlgy when you reconnect the cable there is no problem...

I think this cap removal always makes the player sound so much better that even little clicks and pops are acceptable 🙂

Ergo
 
#66
Basicly you can measure the voltages on both opamps pins 1 and 7
These are actually the same as the pins I was referring to before. These are opamp outputs and the DC should show 0V here (or few mV as said previously.....


Ergo
 
#67
I tried the test as you recommended and there is no problem, the cones don't move at all, and yes I would definetly agree that the better sound is worth a few clicks.

As for the opamp outputs, I can't find any! The only opamp I can find is for the Headphone out. Is this maybe because I have the OSE version? According to the shematic only the standard CD6000 have those opamps before the HDAM module??

James
 
#68
Ouuu, sorry I forgot that you might have OSE version.

Then you see these additional HDAM modules that are lifted off from main PCB by connector pins. Take the row of pins on the "player backside" side of the HDAM modules. It should have 12 pins and if you are lucky the pin nr. 1 is marked somehow.

Now the pins that I'm talking about are nr. 2,5,8,11

If you can't find the marking for pin 1 measure the voltage on the two pins on the both ends of the pin row with DMM + lead and - lead connected to chassis. The pin that shows +12V is the pin 12.

Hope this all makes sense 🙂

Ergo
 
#69
Thanks Ergo, perfect explanation!

I have just checked the pins and there is quite a lot of offset:

pin 2 is 25mV, pin 5 is 70mV, pin 8 is -100mV and pin 11 is 115mV.

The problem obviously comes further upstream. Is there much I can do to correct it or should I just leave it? Obviously I'd like to keep going if I can seeing as Im learning so much 🙂


Thanks

James
 
#71
jnxw2 - aaaa you are on to something here.

As your amp is immune to small DC offset it seems that this might exactly solve your problem + improve the sound some.

At the moment when player mutes the output it shorts the small DC offset to ground and the clicks you hear are from swithing moments. If you remove the mute transistors these clicks should disappear. Of course there might a chance that new clicks appear when changing track etc.

Ergo

PS. Changing the DC offset in HDAM modules is not very easy. Most likely the transistors are not mached quite perfectly. You would need to buy them and select very carefully, but these are most likely hard to get and might cost quite a bit. Other way would be to replace some resistors with small pots but this is also difficult...
 
#73
First post :xeye: Reading through this I noticed the argument between rickpt and, well.... everyone else 😀 I think the main reason behind your different points were where trying to say

: if a component is superior in performance as an electronic component does this nescessarily mean it is better as an audiophile component?

not sure if this should be posted here or in a new thread. however, I was hoping to catch the attention, and opinions of those involved 😀
 
#75
I just removed the muting transistors and shorted out the electrolytic caps in the signal path in my Marantz cd63 mkII.
I also replaced the opamps with a pair of BB opa2134.

Conclusion: I like it. More dynamic sound and a better soundstage.😀

Next up: The clock...
 
#77
Hello,

I have done the same things to my CD63 as Chris. Removed muting resistors and dc output caps, replaced diodes with Fairchild Stealth diodes etc.

I currently have OPA2132 in my player and I do not like the sound at all. I much prefered the sound with AD827.

The BB op-amps are too 'slow' and 'vailed' for my liking, I like speed & resolution.

I have some OPA2604 that I could put in, but I figured they would not sound much different than what I have in now.

Has anybody paralled op-amps? and what experiences have they had? (literally stacking/soldering two op-amps on top of each other)

Thanks

KevinLee
 
#78
an update:

ive removed the muting transistors - and swapped the HDAM for two OPA2604's - im now at a loss of what to do - i would like to put in a new clock but i dont know how to and i would like to make my own and would like good guides - if anyone could help PLEASE
 
#80
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