Cambridge Audio CD3 Player

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#21
CD3

Hi Jean-Paul,

I'll check the value of R25 when I get home from work and post the info here.

So the print for diode orientation on the power supply PCB is correct... Makes my problem even more puzzling.

I have no 5v present on the output pin of the LM317 putting the problem somewhere between the diode and the regulator.

Maybe there's a bad solder joint on one of the adjustment resistors for the LM317...??? Have to check that when I get home.

Can't see how a bad cap on the power rail would cause this symptom, but maybe there's a bad cap involved...??

Gonna be an expert at this machine soon.

Thanks for checking the diode print orientation 🙂
 
#22
TV man, you are making a small thinking error. The near 0 Volt at the output of LM317 can occur when too much current is drawn. A short circuit in the 5V line elsewhere in the cdplayer is a possibility. As you said the regulator gets instantly hot this might be the case 😉

Just disconnect the DAC board and see if you've 5V again.
 
#23
CD3

Hi Jean-Paul,

Ran home for lunch and had a peek at the CD3...

R25 (near D7 & D10) is rated at 31 ohms by the color bands, although the orange band looks like it might be faded red. I measured it and got 27.5 ohms which would put it in spec for 31 ohms +- 10%.

Thanks for the correction on the regulator problem... I have measured without the D/A daughter card connected and still get .1v on the LM317 output pin. Maybe a short between the output pin and the power ribbon cable socket..?? Will check for this later as my lunch break is over 😉

Back to work...
 
#24
jean-paul said:


So I don't see a reason for *not* making this cdplayer non os. Chipset is identical to other normal Philips cdplayers. The 16 x Fs process is done after the SAA7220 on a separate board with shift registers.
Click to expand...

So the registers are used to make 16*Fs, interesting. Now that you say it, it does ring a bell. I still think they are working on the i2s dataline, delaying samples. So at one point in time you have the current and previous samples available to load the tda's. And then adding up the outputs, which are then NOT outputting the same data (current). Current outputs connected together = currents added.

And i think the shift registers are loading the data coming from the 7220. When moving to non os in the normal way (remove 7220 and connect the shift registers to the 7210 output, it will not work imo.

The output of the 7220 is 16 bit words, the 7210 is 32 bit words. That is why the 7220 output has only double wordclock and not 4 times, as you would expect from 4 Fs. Because half of the bits from the 7210 contain no information, it's wordclock is two times higher than actually needed.

A DAC looks at the i2s ws signal and has no problem with the 16 or 32 bits. The shift registers will not. Instead of loading data, you loading dummy bits (zero?) You might end up with something like the digital decimation principle :->

Not having the schematics, i cannot be shure. But my gut feeling says it will not work without some changes to the logic.

More reverse engineering please !!!

Greetings,
 
#25
CD3

Hi Guido,

I've been thinking about the non os mod too... my impression is that it won't work with the shift registers, but would be easy to implement without them as a straight 4 DAC parallel non-os setup. The 4 DAC chips are on individual daughter cards attached to the D/A section PCB. Reworking the connections to bypass the shift registers should be a snap. But then I'm a junior propellor head stumped by a simple voltage regulator mishap so wtfdik 😉
 
#26
CD3

OK think I found it. Looks like one of the small caps from the 5v line to ground is shorted.

It's one of the little brown ones marked with a 10 and 16v (not the orange .01) on the 5v line.

Will change and test again.

Thanks for your help and patience Jean-Paul 🙂
 
#27
CD3 Progress

Changed the bad cap. Now there's music 🙂

The CD3 had a slight harshness on some of the highs and mid-highs before the diode upgrade. Now most of that is gone. More smoothness with the 11DQ10 in place of 1N4004. Also better seperation of sounds in the same frequency range ie. vocal harmonies mixed with orchestral violins. The diode swap is a nice improvement.

The stock CD3 had a very rich tone. Now it's richer and smoother with better detail at the same time. No thin digital sound with this player!!

All the old electrolytic caps need to be replaced next :devilr:

I drank a glass of wine this evening and meditated on my appreciation for this forum and the patient help from Jean-Paul that brought this round of improvements to my musical enjoyment.

Cheers to you and thanks 🙂

More tweaking to come, long live the CD3!!
 
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#29
GuidoB, I don't see the problems you describe. I just see a standard chipset with the difference that there is a board added after the SAA7220 and that it drives 4 DAC boards.

So removing the SAA7220, 4 x TDA1541A and the 16 x Fs board will leave me a cdplayer with SAA7210 which can output directly to TDA1543. Could be that I am making a thinking error and not having a schematic does not help either but I don't foresee many problems that can't be overcome.
 
#30
jean-paul said:
GuidoB, I don't see the problems you describe. I just see a standard chipset with the difference that there is a board added after the SAA7220 and that it drives 4 DAC boards.

So removing the SAA7220, 4 x TDA1541A and the 16 x Fs board will leave me a cdplayer with SAA7210 which can output directly to TDA1543. Could be that I am making a thinking error and not having a schematic does not help either but I don't foresee many problems that can't be overcome.
Click to expand...

Jean-Paul,

You are absolutely right about that, i thought you were going to use the logic and 1541's with non os.

It's when you would put the logic and dacs after the 7210 there are problems (i think from the info i have now).

Guess there is enough space available when you have removed the pcb's.

Succes!
 
#31
jean-paul said:
GuidoB, I don't see the problems you describe. I just see a standard chipset with the difference that there is a board added after the SAA7220 and that it drives 4 DAC boards.

So removing the SAA7220, 4 x TDA1541A and the 16 x Fs board will leave me a cdplayer with SAA7210 which can output directly to TDA1543. Could be that I am making a thinking error and not having a schematic does not help either but I don't foresee many problems that can't be overcome.
Click to expand...

Some last remarks, but you will most definately know this already. So for the person who would read the post not knowing:

- spdif out is most likely coming from the 7220, so gone. New transmitter needed to get it back again (but i guess you don't need it). Or just leave the 7220 just for spdif.

- xtal is probably connected to the 7220, so it needs to be moved to the 7210. Time for a different clock? Again, or just leave
the 7220 for the clock generation.

Depends on the ammount of changes you are willing to make on the main pcb.

Greetings,
 
#34
Cambridge Audio CD2-3 service manual

Hello
I spoke to Stan Curtis the designer of the Cambridge Audio CD2 and Cambridge Audio CD3 he has both service manuals for the Cambridge Audio CD2 and Cambridge Audio CD3 it is just he is not very helpful with DIYer's for what reason I do not know 😡 but maybe if enough people E-mail him he will hopefully give in and kindly help us 😉 but he definitely has them 🙂 !
These are his E-mail addresses divacorp@nildram.co.uk
mail@stancurtis.com
 
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#35
Good enough reason NOT to buy C@@bridge A##io huh? It never ceases to amaze me when companies refuse to provide service information to legitimate owners of their gear or service technicians. I had a fight with S##sung trying to get a service manual recently, ended up getting one, for free on the 'net and emailing it to them with a big smile.
C@@bridge cannot seriously think they have some trade secrets in that old thing...
 
#36
paul_peraic said:
Hello
I spoke to Stan Curtis the designer of the Cambridge Audio CD2 and Cambridge Audio CD3 he has both service manuals for the Cambridge Audio CD2 and Cambridge Audio CD3 it is just he is not very helpful with DIYer's for what reason I do not know 😡 but maybe if enough people E-mail him he will hopefully give in and kindly help us 😉 but he definitely has them 🙂 !
Click to expand...

I am definitely interested in the manuals.
But I don't really feel like bothering him directly by e-mail...
Do you know if he looks at diyaudio?
We may "kindly insist" in a more discreet way.

(...and what I am looking for is the DAC-3 with 4xTDA1541AS1; the DAC part is probably identical to the CD3, but there's this SPDIF section too...)


_
 
#37
Hello
I do not know of any other way but to ask him he seems to intentionally
not want to be helpful to DIYers for what reason I do not know , he now states that he does not have them when only 2 months prior he said he did have them ? 😡
With DIY audio I do not think he is a member I know he occasionally visits
WigWam and his name is organstan there he also is a member of the Lecson Audio Group also under the name of organstan , but to discreetly ask will not work this guy to me is just not helpful in any way , I am not saying he is a bad guy it is just he makes no effort , DIYers seem to be an annoyance to him which I think is wrong because we have brought his designs to a cult following which I believe is good business for him so he can call himself guru and the like , If people such as ourselves have given him this status the least he could do in return is graciously give his followers a simple 20 + year old schematic. 😕
As for the Cambridge Audio DAC-3 they are very rare if you look at this post the pictures I have there are of the DAC-3 (http://www.diyaudio.com/forums/showthread.php?t=119408&highlight=Cambridge+Audio+Player&page=8)
I am still kicking myself for not buying this straight away it had a buy it now price on E-bay for 300GBP but I have a CD3 and it looks exactly the same except that it has no transport and Stan also had mentioned that it literally was a CD3 with out transport but with SPDIF 🙄

I think some sort of petition might work the Lecson Audio Group he is a member of I think gathers information on obsolete equipment so maybe a petition there would work unless any one has better suggestions ?
 
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#39
restorer-john said:
Good enough reason NOT to buy C@@bridge A##io huh? It never ceases to amaze me when companies refuse to provide service information to legitimate owners of their gear or service technicians. I had a fight with S##sung trying to get a service manual recently, ended up getting one, for free on the 'net and emailing it to them with a big smile.
C@@bridge cannot seriously think they have some trade secrets in that old thing...
Click to expand...
It is not the current Cambridge Audio's exact fault , though they do not make any effort in acquiring these schematics they state that it is not there intellectual property which I guess it is not , but it is also an easy way to not be responsible for prior products even though it has nothing to do with the current company it still is a Cambridge Audio and in no way a professional attitude for such a renowned company? 🙄
Stan Curtis owns the rights to the old Cambridge Audio I believe ? , he just does not wish to be responsible for his products 😡, which I believe is wrong it does not matter how old the machine is , you have a responsibility for service of the machine I have chatted to a lot of Cambridge Audio technicians world wide in trying to find these schematics , they get so many requests for repairs of these machines ,
but absolutely no technical support from the owner of these supposed intellectual properties , as in not even the technicians that repair these players have any technical access to such necessities.🙂
 
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