General Purpose DAC Clock Board

Hi tamra,

Yes, I understand 🙂

The clock should get even better over the next 6 or 7 days, if its a new one. Just leave it powered up during that time whether you are listening to music or not.

Best,
Mark

BTW, for those readers who are not familiar with "SC Pure," it is the brand name Iancanada uses for his clocks. IME they are way, way, way better than Crystek, Accusilicon, and or NDK SDA. Some people seem to have trouble believing it can be possible, but with Marcel's dac it makes a big difference.
 
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BTW, someone mentioned to me about this High Speed PCB Design place: https://speedingedge.com/

They have published some books and newsletters. Here is a little snippet from one book:

View attachment 1345192

Turns out they don't like ferrites.

I guess this is from people interested in very-high-speed digital circuitry, rather than in controlling crosstalk in a mixed-signal design. Ferrite beads can be quite effective when you want to control crosstalk via magnetic coupling or common-impedance coupling, and a bit of extra ripple on the aggressor supply domain is often no problem.
 
Yes, probably so. Still, for audio dacs there is something about ferrites that seems to make the sound brittle. Maybe it is the hysteresis distortion. Also, I still maintain that phase noise plots do not tell everything about time jitter. RMS jitter can only be estimated from such plots. Peak time jitter, not so much.
 
I believe the much lauded Ian SC Pure uses UK made RFX OCXO clocks. With no disrespect to his amazing work and development and offerings to the DIY community, is there any benefit you very capable guys designing your own oscillators using the RFX parts? Even if only for your own use/ curiosity?!
 
For one thing, crystals have an MOQ for each frequency (minimum order quantity). Therefore someone has to become a reseller and stock them, or else organize GBs.

Other than that, my position has been that I am only willing to design things diy'ers should have available for dac building, but that aren't sold. I almost didn't do my own reclocker until I started doing some checking to see if the ferrites on my old reclocker were having any effect on the sound. Turns out they did have an adverse effect. And so did the nonlinear bypass caps but to a lesser extent. I felt somebody needed to fix that but apparently nobody else wanted to do it, so I did the reclocker project. Don't see a similar need with clocks themselves.
 
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Thanks for the reply and for clarity I think I need to add some further points.
Above I inferred that the SC Pure uses RFX OCXO. I believe I am wrong there as I have just seen that Ian offers RFX OS400 OCXOs but they are a different item to his SC Pure, which I believe uses a Laptech crystal.
Sorry for the duff info.
 
Hi Mark,
I am ordering parts for clock board,reclocker and pcm2dsd.

For Pcm2dsd board, It's difficult to get XC6SLX9TGQ144 here so I will make it later.

I have some questions for the clock board resistor and caps value.
R3,4,5,6,11,14,21,22
C1,2,9,10,11,12,16,17,18
Any specific value for D1-D3
What is TP2?