Has anyone replaced the onboard oscillator of the CD-PRO2 unit with an external low jitter clock?
I have searched the forum but didn' t manage to find something about this. There was a post somewhere regarding this issue, but things were not clear.
Reading the manual of the CD-PRO2 I find that there is a connector with the designation "16 MHz (optional)", but, as far as I understand this, ths is for providing the internal 16 MHz clock to an external unit.
I' m interested in building a KWAK-CLOCK and feeding my unit with it.
What I' m asking is where should I connect the clock (and from where should I disconnect the onboard clock). Has anybody some kind of experience with such a modification?
Evangelos
I have searched the forum but didn' t manage to find something about this. There was a post somewhere regarding this issue, but things were not clear.
Reading the manual of the CD-PRO2 I find that there is a connector with the designation "16 MHz (optional)", but, as far as I understand this, ths is for providing the internal 16 MHz clock to an external unit.
I' m interested in building a KWAK-CLOCK and feeding my unit with it.
What I' m asking is where should I connect the clock (and from where should I disconnect the onboard clock). Has anybody some kind of experience with such a modification?
Evangelos
New clock in CD-PRO
Hi Evangelos,
You almost answered your own question.
Just remove the original crystal and the two small caps as in the picture kindly provided by Peter.
You now have to connect the output of the KWAK-CLOCK to one of the pads of the original crystal connected to CRIN.
If you can not determine from the schematic wich pad is connected to CRIN just try both pads, one at a time, with a 1k resistor in series wth the clock-output. Keep the pad that works and remove the 1k resistor.
I hope to visit your beautiful country soon.....
Hi Evangelos,
You almost answered your own question.
Just remove the original crystal and the two small caps as in the picture kindly provided by Peter.
You now have to connect the output of the KWAK-CLOCK to one of the pads of the original crystal connected to CRIN.
If you can not determine from the schematic wich pad is connected to CRIN just try both pads, one at a time, with a 1k resistor in series wth the clock-output. Keep the pad that works and remove the 1k resistor.
I hope to visit your beautiful country soon.....
I've made that modification. I don't remember what pin is the right one but this is critical. One of my SAA7324 died in this experiment 
so take care, the chip is very sensitive.
My Philips dealer said it cannot provide this chip even if I wanted 1000 pcs.
I will look and tell you about the real clock input.
so take care, the chip is very sensitive.My Philips dealer said it cannot provide this chip even if I wanted 1000 pcs.
I will look and tell you about the real clock input.
Thanks all for your input.
I've made that modification. I don't remember what pin is the right one but this is critical. One of my SAA7324 died in this experiment so take care, the chip is very sensitive.
That's exactly what I' m afraid of about intervening in such a compact, delicate and with sensitive parts unit as the CD-PRO2.
Lupulroz,
Since, from what you posted, I understand that you have modified quite a large number of CD-PRO2 units, can you tell us, from your experience, some useful precaution and modification tips for disconnecting the internal crystal and attaching an external oscillator? I have seen that there are a lot of diyAudio forum members that have already built a CD-PRO2 based player and I guess that some of them would like to try the "clock upgrade". Any sharing of your experience would be useful.
By the way, my most recent measurements on a Kwak clock showed horrible results.
Guido,
Do I sense a strong controversy here? "Horrible" is such a grave word to describe. Could you elaborate on this?
Regarding crystal frequency, I quote from the SAA7324 data sheet:
Typical oscillation frequencies required are 8.4672, 16.9344 or 33.8688 MHz depending on the internal clock settings used and whether or not the clock multiplier is enabled.
How can someone check what is the frequency used in the unit he has in hand?
Best regards to all,
Evangelos
I've made that modification. I don't remember what pin is the right one but this is critical. One of my SAA7324 died in this experiment so take care, the chip is very sensitive.
That's exactly what I' m afraid of about intervening in such a compact, delicate and with sensitive parts unit as the CD-PRO2.
Lupulroz,
Since, from what you posted, I understand that you have modified quite a large number of CD-PRO2 units, can you tell us, from your experience, some useful precaution and modification tips for disconnecting the internal crystal and attaching an external oscillator? I have seen that there are a lot of diyAudio forum members that have already built a CD-PRO2 based player and I guess that some of them would like to try the "clock upgrade". Any sharing of your experience would be useful.
By the way, my most recent measurements on a Kwak clock showed horrible results.
Guido,
Do I sense a strong controversy here? "Horrible" is such a grave word to describe. Could you elaborate on this?
Regarding crystal frequency, I quote from the SAA7324 data sheet:
Typical oscillation frequencies required are 8.4672, 16.9344 or 33.8688 MHz depending on the internal clock settings used and whether or not the clock multiplier is enabled.
How can someone check what is the frequency used in the unit he has in hand?
Best regards to all,
Evangelos
External clock
Hi Evangelos,
The datasheet for the SAA7324 can be downloaded here:
http://www.semiconductors.philips.com/pip/SAA7324H_M2B.html
It clearly shows that the CRIN is pin16.
As for your last question the frequency of the crystal is usually printed on it. I presume the crystal is located very near pin 16. The crystal looks like a flattened oval metal cylinder, couldn't miss it.
Hope this helps.
Hi Evangelos,
The datasheet for the SAA7324 can be downloaded here:
http://www.semiconductors.philips.com/pip/SAA7324H_M2B.html
It clearly shows that the CRIN is pin16.
As for your last question the frequency of the crystal is usually printed on it. I presume the crystal is located very near pin 16. The crystal looks like a flattened oval metal cylinder, couldn't miss it.
Hope this helps.
Hi Elso,
Thanks for the input.
I had already the datasheet for the SAA7324.
My question was mainly of an informative and practical nature regarding this modification: if someone has already done this, I would like him to share his experience on such a delicate (IMO) "surgery". Also, his opinion on whether this is worth trying, relying on the benefits of this modification.
Anyway, thank you.
Thanks for the input.
I had already the datasheet for the SAA7324.
My question was mainly of an informative and practical nature regarding this modification: if someone has already done this, I would like him to share his experience on such a delicate (IMO) "surgery". Also, his opinion on whether this is worth trying, relying on the benefits of this modification.
Anyway, thank you.
Re: Re: Re: External clock to CD-PRO2
I measured the spectral response. It contains loads of RF (FM radio stations and others), but even worse, mixed products of harmonics of the mains at (only) -35 dB.
I did not measure jitter, but the spectral response needs to be cleaned up first.
I measured other clocks as well (LC audio, my own and the HP reference clock), as well as the set up, which was clean to -80dB.
I will perform jitter measurements once I have my HP53310A modulation domain analyser up and running.
If someone has a Trichord and an Audiocom available, I'd be willing to measure these as well, I am not wanting to pay for these expensive things
all the best,
jean-paul said:
I measured the spectral response. It contains loads of RF (FM radio stations and others), but even worse, mixed products of harmonics of the mains at (only) -35 dB.
I did not measure jitter, but the spectral response needs to be cleaned up first.
I measured other clocks as well (LC audio, my own and the HP reference clock), as well as the set up, which was clean to -80dB.
I will perform jitter measurements once I have my HP53310A modulation domain analyser up and running.
If someone has a Trichord and an Audiocom available, I'd be willing to measure these as well, I am not wanting to pay for these expensive things
all the best,
kenev said:
Hi
The spectral content should be absolutely clean, at least down to -100dB from the carier, respecting some phase noise closeby.
So far, I can measure down to 80 dB, but I am setting up experiments to go deeper.
Jitter measurements (in the time domain) will follow
best regards
-
Guido
CD Pro clock
Hi,
I have been toying with the CD-Pro 2 unit for a while. In stock form, it is not as good as my modified Theta Jade. However, I am really keen to try a new clock on the unit.
Problem with the above is that I can't figure out which is the crystal. After some enlightening posts here. My guess is that the crystal freq is 8.4672MHz. I have attached a picture of where I think the relevant elements of the orginal clock configuration is. Please take a look & comment if it is accurate.
Regards,
Joe Ling
Hi,
I have been toying with the CD-Pro 2 unit for a while. In stock form, it is not as good as my modified Theta Jade. However, I am really keen to try a new clock on the unit.
Problem with the above is that I can't figure out which is the crystal. After some enlightening posts here. My guess is that the crystal freq is 8.4672MHz. I have attached a picture of where I think the relevant elements of the orginal clock configuration is. Please take a look & comment if it is accurate.
Regards,
Joe Ling
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