Yes very good, but the picture only shows a single core wire, not co-ax or at least twisted pair. Where is the return in relation to the clock signal, its physical location as playing wirth clocks and adding impedance mismatches does not do the clock signal any good. The proximity of the return to the signal is critical for clocks.
In this case here is maybe about some old pictures of the non finished set up... Not the final one, I suppose.
In fact I do not like very much the idea of an oscillator quite far from the "point of interest", wires and so to transport the high clock frequencies. So short the clock path, so good...
I agree with your above comment.
By the way, for the 27Mhz oscillator/clock is not necessary to feed the clock signal on the old oscillator tabs (under the main board). This is quite difficult and is about very long signal path to rich that point. There is an via which make the connection between that oscillator output and the processor clock pin, on the upper side of that board. Or one may use the processor pin to connect the better 27Mhz clock (and the GND somewhere near that pin).
In fact I do not like very much the idea of an oscillator quite far from the "point of interest", wires and so to transport the high clock frequencies. So short the clock path, so good...
I agree with your above comment.
By the way, for the 27Mhz oscillator/clock is not necessary to feed the clock signal on the old oscillator tabs (under the main board). This is quite difficult and is about very long signal path to rich that point. There is an via which make the connection between that oscillator output and the processor clock pin, on the upper side of that board. Or one may use the processor pin to connect the better 27Mhz clock (and the GND somewhere near that pin).
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I bought it from here:
0.81mm Mini Coaxial Cable, RF Cable, RF Coaxial Cable, Small Cable, Cable Specification, stripping coaxial cable, Manufacturer, Supplier, Factory
Satisfied so far with the business...
Here is another supplier: http://ecmstockroom.com
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I use a hard twist of Kynar wire, silver-clad copper. Not the cheap Taiwanese Kynar stuff - but you have to buy 100M at a time and its not cheap. Works well.
Cheers, Joe R.
Hi Coris
What brand 125MHz are you using on the Sabre DAC?
May I suggest you try one of the new "SAW" Oscillators (doesn't mean it has a saw shaped output).
SAW stands for "Surface Acoustic Wave".
I would like you to try this one from Element14 (Farnell), part number 1907485 - described as "low jitter" etc, but reputedly has a noise floor -12dB to that of standard oscillators. And they are not expensive to try.
Here is the PDF file: www.farnell.com/datasheets/1563925.pdf
For info on SAW type oscillators: SAW Oscillator
Cheers, Joe R.
What brand 125MHz are you using on the Sabre DAC?
May I suggest you try one of the new "SAW" Oscillators (doesn't mean it has a saw shaped output).
SAW stands for "Surface Acoustic Wave".
I would like you to try this one from Element14 (Farnell), part number 1907485 - described as "low jitter" etc, but reputedly has a noise floor -12dB to that of standard oscillators. And they are not expensive to try.
Here is the PDF file: www.farnell.com/datasheets/1563925.pdf
For info on SAW type oscillators: SAW Oscillator
Cheers, Joe R.
The ideal cloack wave form is retangular.
See the change !!
It is measured of 25 MHZ clock
Actually, the shape of the clock oscillator does not translate in to how good the oscillator is... in fact, the shape means nothing; maybe that the CRO probe you used’s been calibrated ok...
Here and "There" you'll find a lot of info on what constitutes a good clock oscillator.
I have attached the pdf document that explains what specs are important, and how to measure them. This should be the starting point. I used these caned oscillators almost 10 years ago -> they were top of the range back then.
Boky
PS
Due to the file size limitations, I had to extract only the most important page, page 1 of the pdf....
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Hi Joe
Thanks for the infos.
There was a time when I used an 125Mhz oscillator in my experiments with Sabre DAC. There was not about an high end oscillator, but an quite ordinary one with the best parameters I could find for a reasonable price. It worked very fine.
Then I used some matched frequency oscillators (multiple of 48/44,1 sampling) 122,880 and 112,896 Mhz. The best (sonic) result I had with 112,896 Mhz. This one is an Fox oscillator, and the only one I could find at this frequency. Over 100Mhz is quite difficult to find a matched oscillator for audio use. This last one oscillator I used was definitively better than 100Mhz (max "standard") one. I do not know exactly the explanation for why the system behave better with an clock frequency that is higher than the designer of the DAC chip recommend as max frequency. A possible explanation could be that about a lower jitter for a higher oscillation frequency. Even tough this my oscillator is not a very special one, it seems to have a lower jitter than the 100Mhz Crystek one. Jitter is depending frequency as known. Anyway I have no better explanation per to day...
I think to start soon another series of experiments, with a little better control for the ESS8018 parameters, and different clock frequencies. This maybe will bring to me some more informations about how the things really works...
It could be nice to hear from another ones about their impressions/results/confirmations in using high frequencies for clocking Sabre DACs
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I really think too that the shape of the signal for an clock oscillator do not matter much. It can be sinus or rectangular. The clock signal is anyway adapted inside the receiver chip in that manner to minimise errors for use in further circuits inside the respective chip. So, that sinus to be seen in your picture is made rectangular inside the ESS9018. But lower phase noise and jitter from a much better oscillator (OCXO) than that standard one used in BDP95/93, it brings for sure better results...
I have been using Fox as well, indeed that is what I am using for 25MHz.
I still think you should try the "SAW" oscillator, as these have much higher stability and are made especially for high MHz use, indeed they can be used for making highly stable GigaHertz oscillators. The are not Xtal based, more stable and more rugged.
As we can probably agree, it is nice to get the right freq, but in this case there may be a plus even if that more ideal freq cannot be achieved.
You trusted me when I talked you into "double-clocking" the Oppo 95, maybe you could trust me on this one as well and try it (Farnell # 1907485), and they are cheap. Try it, I am keen on getting your feedback, and for the Buffalo guys out there, we may have something interesting to tell them.
Cheers, Joe
Interesting thread. Been fooling with 'audio' since '71.
Never heard even a mention of Oppo 'till last few days.. Here.
Curiously I went and googled.
These odd Rascals are cheaper than their Sony counterparts, but not seriously so.
Been down the CD and modded CD /dvd gizmo path before.. repeatedly.
Sounds were OK and slightly better after countless hours and some fairly serious coin ... but still NO threat to my ancient vinyl, clicks pops and all...sad but also true.
No matter.. as there are very few ( 2 or 3?) CD selling shops left standing Here in Vancouver. Likely a fairly representative situation, as a guess?
Who the hell ..buys ..CD's these days?? Old men I suppose?
Even More pertinently: Who in Hell Buys DVD's?? Seriously?
Frankly easier to find new releases in Vinyl than Disc.. true.
Certainly A new and improved CD gizmo has appeal as a 'New Toy'.
Hey! I'd like one ..but not for $1/$2K though
Thinking this as the Future? Now that's a Stretch
Never heard even a mention of Oppo 'till last few days.. Here.
Curiously I went and googled.
These odd Rascals are cheaper than their Sony counterparts, but not seriously so.
Been down the CD and modded CD /dvd gizmo path before.. repeatedly.
Sounds were OK and slightly better after countless hours and some fairly serious coin ... but still NO threat to my ancient vinyl, clicks pops and all...sad but also true.
No matter.. as there are very few ( 2 or 3?) CD selling shops left standing Here in Vancouver. Likely a fairly representative situation, as a guess?
Who the hell ..buys ..CD's these days?? Old men I suppose?
Even More pertinently: Who in Hell Buys DVD's?? Seriously?
Frankly easier to find new releases in Vinyl than Disc.. true.
Certainly A new and improved CD gizmo has appeal as a 'New Toy'.
Hey! I'd like one ..but not for $1/$2K though
Thinking this as the Future? Now that's a Stretch
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According to the experts, conventional oscillators are "BAW" devices. These are less likely to be stable as you increase the frequency. The datasheet will rarely ever mention "BAW" as they are so by default anyway and no need to mention it - but if it is a "SAW" oscillator, they will definitely say so in the datasheet.
Cheers, Joe