Marantz CD63 & CD67 mods list

[Chivvyp]

Thanks guys, seems to be a concencus on this stuff. I've ordered some.

Pete

[bikeral10]

i have a cd 63se the transport going ape checked voltage on the 7918 all over the place any ideas ??.
cheers alan

[higlander]

Originally Posted by bikeral10

i have a cd 63se the transport going ape checked voltage on the 7918 all over the place any ideas ??.
cheers alan

I think your laser is approaching its end of life. If that is the case there is no harm to trim the laser pot to increase the voltage of the laser led and see if it helps

[bikeral10]

Originally Posted by higlander

I think your laser is approaching its end of life. If that is the case there is no harm to trim the laser pot to increase the voltage of the laser led and see if it helps

Not the transport at fault fitted it to another player works fine ,Had a faulty clock sometime back this is two players doing the same thing. just checking voltage laser like a machinegun only spare machines so no problem
alan

[higlander]

Just an update. The low jitter clock arrived last weekends and I have fitted it onto the modded CD63 as the last item. I have returned the CD63 to my friend and he is extremely happy with my work and cannot believe his ears by the great improvement in SQ from this modded CD63 I told him if he has bigger budget I will use better quality components in the machine and the improvement will be even bigger .

[dwjames]

Hi all,
What a thread!
I've got a CD63 with a valve output stage (not my own work) which I've also since done some basic tweaks to, and I've done a LOT of reading of this thread and other helpful sources like Martin Clark's Acoustica.org.uk, Ray's PDF lists and Thorsten's info on the TNT site, but I'm no electronics expert...

Here's a quick pic from before I messed around with it...


I was really pleased with the sound of it generally, but there was an underlying interference noise I could hear when I played it at volume bothered me...
Here's a crappy video which shows the noise I was getting.
https://www.dropbox.com/s/lei5vyal70...2011.36.05.mov

Because of the valve output stage, I'm not using anything after RO and LO from the DAC. But the valve stage mod left all the standard components in-tact with the exception of removing the RCA plugs on the back. I found that by cutting the pin 2 going to the 2 opamps Q605 Q606 in the output stage directly after where the RO and LO feeds were taken reduced the noise about half.



This took the edge off, but there was still a lot more hissssssssss than I'd like..

So I did a few basic mods and followed Martin Clark's guide to add some decoupling caps for the DAC, move the caps for the crystal and cut the track to sort the ground bounce and such. Very happy with the results

but he mentioned how a separate 5v feed to the DAC would help and after a helpful email or 2, I've added 3 new 5v feed to the DAC using 3 x simple 7805s for now. I also had a quick go at adding those tiny weeny decoupling caps directly to the DAC legs, but I fairly quickly chickened out of such a delicate job and added some 100nf WIMA film caps in the original ceramic locations instead. I also increased the electrolytic caps for the DAC 5v supplies and moved them closer into the ceramic locations too.

I beefed up the larger Power supply caps while I was there as this player's not even an SE, so some were tiny.
Here's a comparison of old and new C804 C805 caps..


Here's a quick couple of pics of where it stands now:




I'm very impressed with the results now, the detail and focus has really improved

Where am I going with all this?
well basically, I'm not interested in pushing this to the Nth degree or spending a huge load of time and cash, but I'm still getting an interference hissssssssssssss which can go almost undetected with quieter listening, but when I've got it cranked and I'm listening to something with a quiet, delicate section, is still quite pronounced. I'd be thrilled and consider this project complete to get those deep, dark silences rather than fuzzy grey ones and I'm convinced there's a few basic mods I can still do which will help.

My next round of mods is to change out the power supply diodes for Schottkey 11dq10, decouple some of the larger power supply caps with 100n PPS or XR7 as per Ray's list and maybe filtering the power input with a IEC socket and Choke and Cap.

But I can't help feeling that if a major problem with this player is an overloaded and noisy 5v+ circuit, that having a load of unused crap still connected can't be helping things....
Is there a simple way I can totally cut off the unused standard output stage/hdam and headphone output and such from the power supply so it's no longer connected? Can I just remove all the caps north of the DAC supplies or are there some jumpers I can cut?

I also have a couple of 7805 spare. Do you think I'd see any real gains from using these for the decoder?

Also, seems like a total newbie question, but what type of wire should I be using for connecting the input of these new regs to the 10v rail and are there any techniques I should be observing to limit interference here? I see a lot of twisted pairs with 1 end not connected in other people's pics?

cheers,
James

[UV101]

Lots of work gone on in there nice!

All the 5v feeds inc the decoder will benefit from separate regulation. I would feed the individual rails for it with separate regs. While you are doing that, you could also do the same for the HF amp

One of the issues is see is that the valve stage only uses half the output if the DAC. I don't think this is ideal! Maybe your hiss problem could be related to this in so far as the gain required is maybe a bit high. I've looked at those valve stages before and although I've not listened to one, I've no desire to play with one for that reason. I'll take Rays DOS (discrete output stage) over that valve stage all day.
Also, the caps you have changed in the power supply for the 1000uf silmics are doing nothing!!!!!!! The valve stage replaced the entire analogue output stage....those caps only supply the analogue output stage.

For now, I'd add some more regs and see what you think

Btw, quick win is to replace c813 with at least 10,000uF (I'd use 22,000uF) it very important. At the same time, wire out the 2 glass fuses

[dwjames]

Thanks for the input

I appreciate its never going to be the worlds best, but I really enjoy listening to it and I like the steampunk simplicity of the valve stage

Yeah the valve output stage is only using half the DAC output. I can see how more gain needed for a quieter signal could highlight the hiss where usually its not detectable so maybe it's here to stay...
I'll add a few more regs like you say and disable the power to the standard output and such and see where that leaves me.
Cheers for the heads up on the c804 c805 caps, lol. That kind of highlights where I'm at... It's hard to decider which mods are for what and which are applicable if my output stage is ignored. Does that also mean there's no point in me swapping out some of the Rectifier diodes?

How do people usually disable the standard output stage from the power circuit if they're using a DOS?

Also, out of interest, is the recommended chassis damping to reduce mechanical resonance or electrical interference? Or a bit of both?

Cheers,
James

[luke2fr]

Got a very used looking philips 711 cdp this morning : no pb with the CDs my cd57 has a bad time with. I'm gonna swap their CDM12.1
That's 15euro well spent

[hotiron]

Hi James those Green resistors (8 of them) between the op-amps and Hdam screen cans R613 R651 Etc. supply power to the output stages. There are also a couple of jumpers feeding these resistors I don't have the schematic for the 63 at hand but U223 and U224 look like the ones you need to snip. Check with your meter first!