The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator

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Correct me if I'm wrong, since it's audio, the audible traits would be the main focus.

So far so good?

Next, a question, what does or did upgrading to Andrea's oscillator improve for audio?

I have no idea what you are asking or the point of your message.

I do not wish to engage with you, please do not reach out through any means.

All the best and thank you.

Seb
 
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Andrea,
Posts like that are not helpful. Show some respect to your peers.

And, measurements are more sensitive than your hearing is. That is a cruel fact. Together, listening and measurements will always keep you on track. But if the measurements do not support what you wish for, maybe its best to return to the stone age and just listen to stuff?
Do at ASR they use a miracle source?
Look this up and answer it yourself. How about any primary standards lab? They will be better than your oscillator. That's a fact, because if yours was better, you would be a rich man. At the very least you would be well regarded in the test and measurement world, and doubly so in the audio world. You would have been contacted by now by many high powered, interested parties from governments and industry. Doesn't matter if you didn't want to sell, they would seek you out.

It would be very interesting to compare your oscillator to an industry standard SC cut quartz oscillator in a double oven. We don't care about absolute frequency accuracy, just short term stability. This works in your favor. Most industry oscillators have a frequency adjusting input, and I'll assume yours doesn't have that feature. Another factor in your favor. The double oven only blocks air currents and temperature gradients in this case. Might be a benefit to the double oven compared to yours that I haven't seen.

-Chris
 
Are FFTs being misinterpreted here - maybe those experienced in FFTs can answer?

Is the FFT plot a graph of power signal density - in other words a statistical plot of how much time the tone is rendered incorrectly at the various close-in frequencies to the fundamental?

Does the -85dB mean that tone is incorrectly rendered -85dB down from the fundamental or does it mean that the tone is incorrectly rendered at full power but intermittently at some percentage of the time i.e a density plot?

If this is the case (& I don't see why not), how does auditory perception perceive this type of spectral spreading of all the tones in an soundfield as the sound envelope progresses over time? It seems to me that this spectral spreading over time would affect soundstage perception (a already mentioned) but also timbre & other elements in the soundfield that require consistent rendition over time.

:key:

The time ... is lost.
 

TNT

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Joined 2003
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Wow, can you share your experience with us?

Maybe we learn something.

Because our dear TNT is the one who can't hear any difference between a 30 cent and a SOTA oscillator.
But he hears huge and clearly audible difference when he replaces the source for his Soekris DAC.

He is measurements obsessed and asks for solid proves about the audibily difference between clocks, but the measurements don't matter when he uses his golden ears listening to Soekris DAC.

So he wonder "Detectable territory? (-85dB)" about oscillators, but he is able to detect -120dB when he listen to the Soekris DAC.

Do at ASR they use a miracle source?

In-coherence defined. I see you half standing over your keyboard typing away in frustration. Please dear Andrea - you seriously need to calm down. Get a grip of yourself man. We are now trying to have a resonable discussion but all you do is flinging insults and confusion. Why are you so angry? If you hade been cool and confident, all these discussions would probably not have taken place at all. Are you so terrible unsure of what you are doing that you need to go havoc in the discussions?

The figures you stated above (e.g. -120 dB and "huge") are total guess from your side - has no foundation and has never been stated. Where do you get these things from? Your view of the discussion you are referring to, which probably most here don't know anyways, is a distorsion of reality. Dude - you seriously need to get a grip of yourself.

//
 
Looking at the Joseph measurements, noise floor is some -170dB which renders a SNR (again counting the process gain of 22dB) of -148dB. A 24 bit ADC like the one in the RTX has a theoretical SNR of -146dB. Interesting result, maybe synchronous averaging was used kick down the noise floor? That would be opening another can of worms, though, since synchronous averaging has it's own jitter contribution...

You are mixing up 1 Hz and the Nyquist bandwidth. -148 dB in 1 Hz is about -104 dB in 24 kHz.
 
D

Deleted member 537459

Andrea,
Posts like that are not helpful. Show some respect to your peers.

And, measurements are more sensitive than your hearing is. That is a cruel fact. Together, listening and measurements will always keep you on track. But if the measurements do not support what you wish for, maybe its best to return to the stone age and just listen to stuff?

Look this up and answer it yourself. How about any primary standards lab? They will be better than your oscillator. That's a fact, because if yours was better, you would be a rich man. At the very least you would be well regarded in the test and measurement world, and doubly so in the audio world. You would have been contacted by now by many high powered, interested parties from governments and industry. Doesn't matter if you didn't want to sell, they would seek you out.

It would be very interesting to compare your oscillator to an industry standard SC cut quartz oscillator in a double oven. We don't care about absolute frequency accuracy, just short term stability. This works in your favor. Most industry oscillators have a frequency adjusting input, and I'll assume yours doesn't have that feature. Another factor in your favor. The double oven only blocks air currents and temperature gradients in this case. Might be a benefit to the double oven compared to yours that I haven't seen.

-Chris

Here is another deaf, to think that audio is made up only of measures is ignorant, there are hundreds of things that cannot be measured but they make a lot of difference.
 
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ligavro,
That was uncalled for, and inaccurate. If this is the best you can offer for a post, best just read.

Hi Andrea,
Yes, really.

Your claims. You back them up.

While you are at it, calm down. You are only asked to provide things you should already know. Nothing unreasonable has been asked of you. You can make the questions stop by simply telling us what you should already know. If you don't, perhaps the community can help you figure these things out.

-Chris
 

TNT

Member
Joined 2003
Paid Member
Maybe, I don't know, what's on the X and Y axis? Is this a phase noise measurement or the spectrum of a 400Hz signal, zoomed and normalized to it's carrier frequency?

Pay attention 007! Even I got that ;)

I think if one participates in a discussion, one need to see to that one interpret what is posted in a correct way. Blaming ongoing other work etc is no excuse. Postpone posting if you are in a rush - topic is semi-advanced so need a bit of concentration perhaps....

//
 
D

Deleted member 537459

ligavro,
That was uncalled for, and inaccurate. If this is the best you can offer for a post, best just read.

Hi Andrea,

Yes, really.

Your claims. You back them up.

While you are at it, calm down. You are only asked to provide things you should already know. Nothing unreasonable has been asked of you. You can make the questions stop by simply telling us what you should already know. If you don't, perhaps the community can help you figure these things out.

-Chris

Your answer confirms what I wrote in the previous post. the "deaf" have to rely only on measurements because as I said, and I don't need to meet you to confirm, you are deaf. it's not a disease, it's just a lack of open-mindedness, a classic of engineers and derivatives. an audio system must not only sound good but must give emotion, it must "see" the music. you can take the best audio components, with the best "measurements" and in most cases you will have a mediocre system. your measurements do not take into account the environment, the cables, the type of speaker and what crossover it has. true, starting from a good situation is better, but again, it is a question of synergies. I ask you "experts" the difference between a 10uf mkp capacitor and a duelund or mundorf capacitor of equal value. at the level of measurements. or the difference between a signal cable from a few euros Amazon and an audioquest earth at 1000 € always at an instrumental level, tell me or you from the top of your intelligence. teach me something, you buy an amplifier by measurement !? like put a McIntosh on some dynaudios !? waiting for an enlightenment ... Gavroche
 
Hi All,

I am really sorry to see this level of "support" for the effort of Andrea (could be anyone else). This forum is supposed to support the development one can't do alone by contribution of the other members. It is not a contest.
Please if you can't contribute don't pollute the tread.
I have not seen any other member doing similar work, so please let Andrea do his thing, If anyone thinks they can do better, please do so and we will gladly follow that project too.
I am too stupid to contribute but smart enough not to ruin it for others.
 
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