Philips CD104 tweaks

[jives11]

Originally posted by wojtek.l
I replaced a lot of caps, analog section and added special ground like cd 7550 ... and it isn`t bad indeed. In start it had hagridden sound!

anyone have a schematic for the CD 7550 ?

[jives11]

Anyone interested in going further, I found a mine of info at this Japanese site. It refers to the Marantz CD-34, but the circuit is the familiar one found in the CD104.

http://www.geocities.jp/tochey_2000/cdp14.html
http://www.geocities.jp/tochey_2000/cdp15.html
http://www.geocities.jp/tochey_2000/cdp16.html
http://www.geocities.jp/tochey_2000/cdp17.html
http://www.geocities.jp/tochey_2000/cdp18.html

[tubee]

I Have a CD300, has presumably same servo and decoder pcb. Can try some of that mods too. All the mods are understandable, except 1 thing: removing rubber dampers underneath CDM-0 into rigid lathed ones?? Where's that for? Far eastern logic i presume (joke)

For the shown reclock my thoughts are: not divide 16,xxx Mhz, but use a kwak 7 and put the original 4,xxx Mhz cristal on it.

[tubee]

Just connected the CD300 and play now some music, the bass is tremendous!!
Unfortuately it has some tracking problems, sometimes a noise is hearable at full scale, lets me jump from my chair! (volumepot is at 5 o clock) So have to resolder connections first.

And now it stopped and doesn't start anymore.....

[poynton]

Hi.

The important thing to do on ALL early boards CD100, 101, 104, 300,303 etc (which use very similar boards) is to solder wires through the ground plane links.

As standard, they rely on the through-hole plating which fails!

This failure causes all sorts of problems including several already mentioned in this thread.

Andy

[jives11]

Originally posted by tubee
All the mods are understandable, except 1 thing: removing rubber dampers underneath CDM-0 into rigid lathed ones?? Where's that for?

For the shown reclock my thoughts are: not divide 16,xxx Mhz, but use a kwak 7 and put the original 4,xxx Mhz cristal on it.

yes some of the mods seem a bit odd. I don't see the purpose of removing the transport decoupling. Perhaps the rubber was hardened with age ? he also replaces the DC blockers with OSCONS, where I think either bipolar or better, no cap should be used B. But the clock changes and other stuff are interesting. Google have a beta Japanese to English translation page which does help a bit

[jives11]

This guy limits his mods to new interconnects and some mass damping. Nice pictures (again)

http://www1-1.kcn.ne.jp/~gx770/CD34.htm

[tubee]

Nice site. This guy doesn't want to hurt his hands on de headsink, made a bar around it!

I don't wanna do much on my CD300 either. A clock, better output caps and some phono chassis connections, some new lytics, thats should be all. Muting is nicely done with reed-relais.

Perhaps the rubber was hardened with age ?

My suspension from 300 + 304 are still soft.

[jives11]

Originally posted by tubee
Nice site. This guy doesn't want to hurt his hands on de headsink, made a bar around it!

I don't wanna do much on my CD300 either. A clock, better output caps and some phono chassis connections, some new lytics, thats should be all. Muting is nicely done with reed-relais.

My suspension from 300 + 304 are still soft.

That has been my experience. Just change the lytics , remove the DC blockers (if you can, my preamp doesn't mind) and fit a new cable. Sounds great

[tubee]

Just opened the CD300, cannot find any soldered connections from upper to bottom pcb. They have grey flat pinned conectors instead. The pcb's are bigger then from the 104, so not the same.

Mains transformer is very peculiar, never seen that before: an air gap of +/- 5 mm between primairy and secundairy winding, you can look straight through it!

Coupling caps are still needed, will be directly connected to the grid of first tube.

they rely on the through-hole plating which fails!

So the earth screens are connected to each other by the screws? A weak point then.