External clock to CD-PRO2

[kenev]

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

[Elso Kwak]

Hi Evangelos,
The datasheet for the SAA7324 can be downloaded here:
http://www.semiconductors.philips.co...7324H_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.

[kenev]

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.

[Guido Tent]

Originally posted by jean-paul


Hi Guido, horrible in what sense ? Jitter, waveform ? I heard/read quite some good responses on Elso's clock.

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,

[Guido Tent]

Originally posted by kenev

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?
Evangelos [/B]

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

[joeling39]

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

[joeling39]

Another picture

[Elso Kwak]

Hi Joe,
This looks more like a SMT crystal-oscillator to me, just as in the Sony SCD-1 or 777ES. Very difficult to remove!
Best done VERY carefully with a hot air gun.
Were some posts on AA on this issue.

[Peter Daniel]

What about just cutting traces, insted of removing?

[joeling39]

Elso,

Thanks for the info. You clock resides in my Marantz CD63KI & is still functioning perfectly after all this while (maybe more than 1 year already).

Regards.
Joe Ling