External clock to CD-PRO2

[Guido Tent]

Originally posted by joeling39
Another picture

Hi

From the picture I see that they did their utter best to place the crystal supporting capacitors as far away from the chip, well done boys, now the RF currents flow all over the board..........

Once you have measured and investigated these aspects, it is so easy........

regards,

[Elso Kwak]

Originally posted by Peter Daniel
What about just cutting traces, insted of removing?

Great idea Peter!
Maybe it is a SMT crystal, I have never seen a thingie exactly like this before.

[Peter Daniel]

Here's the better look, for everybody interested. It is SMD and shouldn't be a problem desoldering it at the 4 points.

[UrSv]

Man that looks like this:

http://202.226.94.5/pdf/e/cx5fe.pdf

[Guido Tent]

Originally posted by Peter Daniel
Here's the better look, for everybody interested. It is SMD and shouldn't be a problem desoldering it at the 4 points.

careful guys, this SMD can be glued as well

[fmak]

Originally posted by 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.

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The glue is evil. But the Sony SCD1/777 one is real easy. Solder wick the joints, and use a 35W iron on the body. Came off straight away and still worked perfectly!!

[fmak]

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.

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Guido

I am going to toy with external word clocks separate from the source clock. Any experience of whta is a good one?

My system with your XO3 sounds significantly different on source clock and internal 10ppm VXCO clock with twin PLL and I don't know why? The setup cocnsist of the XO3 outputting into a dCS 972 DSD/24-192 upsampler. Inserting another twin PLL dejitter device in between changes the sound again and perhaps not for the better!

The influence of good 75R BNC and AES/EBU cables into proper terminations actually controls the character of the sound and is just as significant!! A Belden 1505A 4 m 75R cable sounds worst in the sense that the sound stage flattens and looses image precision.

Comments. anyone???

[Guido Tent]

Originally posted by fmak

Guido

I am going to toy with external word clocks separate from the source clock. Any experience of whta is a good one?

My system with your XO3 sounds significantly different on source clock and internal 10ppm VXCO clock with twin PLL and I don't know why? The setup cocnsist of the XO3 outputting into a dCS 972 DSD/24-192 upsampler. Inserting another twin PLL dejitter device in between changes the sound again and perhaps not for the better!

The influence of good 75R BNC and AES/EBU cables into proper terminations actually controls the character of the sound and is just as significant!! A Belden 1505A 4 m 75R cable sounds worst in the sense that the sound stage flattens and looses image precision.

Comments. anyone???

Fred,

Wordclock: I have been thinking about this too, but cannot come any further than dividing, and eventually reclocking (I like D flipflops very much)

Do I understand correctly that your main clock is not a free running one close to the DAC?

Careful with cascading PLL's, as their poles should be well seperated.......

regards

[fmak]

Wordclock: I have been thinking about this too, but cannot come any further than dividing, and eventually reclocking (I like D flipflops very much)
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Commercial ones are v expensive. I was wondering if there are good diy designs.

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Do I understand correctly that your main clock is not a free running one close to the DAC?

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My dCS 972 ouputs double speed twin links to the 954 DAC. It has its own VCXO which can be enabled, or can lock onto the incoming clock. Alternatively it can use word clock or GPS reference.

The dac has its own VCXO with twin PLL.

So, I have XO3, twin PLL in 972, feeding twin PLL in 954. The latter two are designed to work with each other.

The arrangement is still very sensitive to choice of cable. A RG62 75R cable I bought from Farnell for £6 actually sounds rather good!

[Lupulroz]

Sorry for my late reply - I was offline for a while
Indeed the input clock pin is CRIN - 16.
Yes I modified more units type vae1250 which uses the same SAA7324. The simplest way is to desolder pins 15 and 16 from the pcb and feed clock into pin 16.
I will use CDPRO2 in my future cd-project and I'll be glad to share some results.
The overall sound was pretty good I recommend this modification.
A picture with cd-player that used this approach can be found
here
The product is no more available