Hi sebbyp,
I actually spend a great deal of bench time undoing the damage that hack techs and DIYer's do to equipment. Some DIY efforts are wonder - perfect. Some cause the equipment to malfunction and a few cause irreparable damage. That represents a great loss to he owner, and I would like to minimize that within reason. I do often encourage people to do work they are capable of to reduce their service bill. That is how I run my affairs, I don't actively compete with anyone. Just so you have a better understanding.
I have never moderated anything to my advantage, and often my posts are removed in answer to the misinformation you seem to be posting - and others. The fact is, some of the people in your identifiable group called technical people some pretty insulting things before I ever commented. I'm both a little mystified you can't understand the everything you enjoy listening to, and annoyed, because everything came from the minds of people like me. The ones you accuse of being close minded and an impediment to advancement. Only someone who is incapable of rational thought would call the designers and maintainers of this technology incapable of improving it, and bringing new technology to the table. Think about it, give your head a shake and think some more. Your DAC would not exist to begin with without us.
In my uninteresting case, I have invested my life to audio electronics and over a couple hundred thousand dollars on my personal bench to advance and improve the study of same. So tell me, what have you invested? Where is your commitment? Do you just sit and take pot shots at people who aren't the romantic ideal you have in mind?
What do you do professionally? Are you good at it, and do you invest personal time to become better? I'm easy to figure out. I live, eat and sleep audio electronics. I am trained in it, and also test instrumentation. So I am about as pro-improvement and advancement as you can get. But I also care a great deal about my customers and other folks and will advocate for them - strongly. That means I advocate for you too. I have not asked any questions that do not benefit you and everyone else.
I probably should not have called some people an idiot, but I was frustrated by being called worse and for the sheer lack of logic involved in posts questioning the motives of everyone asking the right questions.
Claims were made. Okay, prove them. That's all.
-Chris
Oh gosh, really? A DAC clock would be such a small part of my business that it isn't worth pursuing to me. I am interested in case I can bring real value to my clients - and I would use Andrea's product if it was better than commercial competing products. That is the real sum total of how my business ventures might intersect with anyone else's. I am surprised you are questioning my motives. I have been crystal clear so far.
I actually spend a great deal of bench time undoing the damage that hack techs and DIYer's do to equipment. Some DIY efforts are wonder - perfect. Some cause the equipment to malfunction and a few cause irreparable damage. That represents a great loss to he owner, and I would like to minimize that within reason. I do often encourage people to do work they are capable of to reduce their service bill. That is how I run my affairs, I don't actively compete with anyone. Just so you have a better understanding.
I have never moderated anything to my advantage, and often my posts are removed in answer to the misinformation you seem to be posting - and others. The fact is, some of the people in your identifiable group called technical people some pretty insulting things before I ever commented. I'm both a little mystified you can't understand the everything you enjoy listening to, and annoyed, because everything came from the minds of people like me. The ones you accuse of being close minded and an impediment to advancement. Only someone who is incapable of rational thought would call the designers and maintainers of this technology incapable of improving it, and bringing new technology to the table. Think about it, give your head a shake and think some more. Your DAC would not exist to begin with without us.
In my uninteresting case, I have invested my life to audio electronics and over a couple hundred thousand dollars on my personal bench to advance and improve the study of same. So tell me, what have you invested? Where is your commitment? Do you just sit and take pot shots at people who aren't the romantic ideal you have in mind?
What do you do professionally? Are you good at it, and do you invest personal time to become better? I'm easy to figure out. I live, eat and sleep audio electronics. I am trained in it, and also test instrumentation. So I am about as pro-improvement and advancement as you can get. But I also care a great deal about my customers and other folks and will advocate for them - strongly. That means I advocate for you too. I have not asked any questions that do not benefit you and everyone else.
I probably should not have called some people an idiot, but I was frustrated by being called worse and for the sheer lack of logic involved in posts questioning the motives of everyone asking the right questions.
Claims were made. Okay, prove them. That's all.
-Chris
Hi TNT,
Yes, a partial answer. The testing needs more controls and I hope to replicate that testing at some point as I do have the equipment and was already planning to do so.
I would also like to define, at least loosely, what actually matters. Then define how much in the way of timing issues exist in the source material people are listening too. There is no point in having a clock 100 x the quality as needed as it would represent a large cost savings to the DIYer. I expect that in some cases the existing clock might be fine. See post #4351 just a couple above.
-Chris
Yes, a partial answer. The testing needs more controls and I hope to replicate that testing at some point as I do have the equipment and was already planning to do so.
I would also like to define, at least loosely, what actually matters. Then define how much in the way of timing issues exist in the source material people are listening too. There is no point in having a clock 100 x the quality as needed as it would represent a large cost savings to the DIYer. I expect that in some cases the existing clock might be fine. See post #4351 just a couple above.
-Chris
Hi Chris, see your point. However, seems to me that if one keeps improving dac clocks (using the same test dac) then when better measuring clocks stop producing audible improvements in SQ, presumably a good enough clock has been found for that particular dac.
Regarding clock-related audible changes noticeable using my AK4499 dac, included are improved imaging, improved resolution of cymbal sound, and improved articulation of snare drum snare wires rattling against the bottom head (i.e. low level transient type stuff).
Once one knows the sorts of specific things to listen for then it should be possible to do listening test of the discrimination type, rather than of preference type. Discrimination tests are mostly the type we do here. Also we find it helps to use very well recorded test tracks for this.
https://www.apps.fst.vt.edu/extensi...ory Analysis/Sensory Analysis - Section 4.pdf
Last edited:
Okay Chris, you seem like a nice and genuine person. Who maybe just let his emotions take control momentarily. I will back off as you seem keen to de-escalate and this isn't valuable to anyone.
I look forward to your positive influence and reading your contributions moving forward. Especially if you set up some of these tests
.
I look forward to your positive influence and reading your contributions moving forward. Especially if you set up some of these tests
.
https://www.diyaudio.com/forums/dig...itter-crystal-oscillator-435.html#post6710701
-126dBc (measured by Joseph) at 10Hz deviation + 22dB (process gain, due to the RBW used, to normalize everything to dBc/1Hz) = -104dB and that's at about 400Hz.
The theoretical value, obtained by scaling the values of the clock frequency deviation, would be, in this case (assuming a 5MHz clock with -120dBc/Hz phase noise @10Hz and a 400Hz signal) 82dBc/Hz better, that is -204dBc/Hz @10Hz deviation.
If I did not screw anything in the quick math above (I have a job too, you know, and it's not an audio operation), there's an almost exactly 100dB gap to explain. I'll let you guys draw the conclusion about what's what.
Hi Mark,
Yes, that seems to be reasonable. The difficult thing is to determine where improvement really exists and that is hard for all of us. But humans are pretty good at comparing things quickly compared to sets of opinions with some time intervening.
What might be a good starting point is to see how bad a clock must be before you can clearly hear it so you notice the impairments, and that seems to be what you are trying to do. Once the effects are known, others can also listen for those things instead of overall "goodness" where the mind can really play tricks. It will be more difficult with a good stock system compared to an improved clock.
-Chris
Yes, that seems to be reasonable. The difficult thing is to determine where improvement really exists and that is hard for all of us. But humans are pretty good at comparing things quickly compared to sets of opinions with some time intervening.
What might be a good starting point is to see how bad a clock must be before you can clearly hear it so you notice the impairments, and that seems to be what you are trying to do. Once the effects are known, others can also listen for those things instead of overall "goodness" where the mind can really play tricks. It will be more difficult with a good stock system compared to an improved clock.
-Chris
Speakers? Yeah, they do cost a lot, especially the good ones.
What are the examples of those fruits?
You need to toughen up. Life is rough. Have you heard an old saying that goes, "Mean teachers are better role models"? It's true, at least what I've seen over the decades. They may seem mean at the time but when you look back after awhile, they are the ones who taught the most / best. If you expect sweet talk all the time and pat on the back on everything, you won't realize what you missed or wrong on something.
There is am obvious third conclusion that you are leaving out here and this makes me think your intentions are not in the best interests of this thread. As a mod I would have expected better.
Its a shame the ignore function does not work for you!
You're adding 22 dB to a number that I already added 22 dB to. At 10 Hz offset, Joseph measured -147 dBc to -148 dBc in one bin, so about -126 dBc in 1 Hz.
Anyway, my calculation is way too optimistic, so there must be some other effect that dominates.
Hi sebbyp,
Like everyone else, I can only do my best. Everyone has to keep an open and reasonable mind. I think once the idea of Andrea being attacked is over, we can all discuss this in a more fruitful and rational manner.
Can we define where the performance of the clock matters and what that actually sounds like? The general order of clock stability would be something like:
R-C network (function generators, timing circuits)
L-C network (RF oscillators)
Ceramic resonator (micro-controller type clock)
Crystal oscillator (common in normal DACs and CD players)
Enclosed Crystal oscillator (Logic circuits,normally square wave output)
Ovenized Crystal oscillator
Double Oven Crystal oscillator (common in good test equipment)
Somewhere in there are temperature compensated silicon oscillators (test equipment, process control)
In that list you can see that crystal oscillators are the most stable. I left out physics standards because short term stability is better with crystal oscillators. You have heard of the various cuts, AT vs SC being the most stable. The SC cut is more stable over temperature, but I would question if this matters in an audio decoding application.
It is easy to simply pick out the best type of crystal oscillator and say it is an improvement over what we are using - but is it really? Sure it is where it matters such as an accurate frequency counter, or even more so in something like a crystal analyzer or a device used to characterize oscillators.
About ovens. They are used to maintain the crystal at a very precise temperature to maintain an exact frequency. In digital audio reproduction, the exact frequency can be off a tiny amount without the possibility of hearing it. It is the short term change that is critical. We would call that wow and flutter on a turntable or cassette or open reel machine. So far in my experience, a good crystal oscillator doesn't require an oven type stability for audio use. They are stable enough as long as you don't stick them in front of a fan or beside something that generates heat. A clean DC supply voltage is also required for the circuit, which would normally be the DSP chip.
So there is some basic ground work for people to think about. In my view, an SC cut crystal in a double oven is total overkill, and also easily available as a custom frequency option (there is a reason why it isn't a stock item in the catalogues). So that technology is stable, mature and well known in the industry. They re expensive and run on two power supplies. One for the oven circuit, the other for the oscillator. A sine output is common.
-Chris
Like everyone else, I can only do my best. Everyone has to keep an open and reasonable mind. I think once the idea of Andrea being attacked is over, we can all discuss this in a more fruitful and rational manner.
Can we define where the performance of the clock matters and what that actually sounds like? The general order of clock stability would be something like:
R-C network (function generators, timing circuits)
L-C network (RF oscillators)
Ceramic resonator (micro-controller type clock)
Crystal oscillator (common in normal DACs and CD players)
Enclosed Crystal oscillator (Logic circuits,normally square wave output)
Ovenized Crystal oscillator
Double Oven Crystal oscillator (common in good test equipment)
Somewhere in there are temperature compensated silicon oscillators (test equipment, process control)
In that list you can see that crystal oscillators are the most stable. I left out physics standards because short term stability is better with crystal oscillators. You have heard of the various cuts, AT vs SC being the most stable. The SC cut is more stable over temperature, but I would question if this matters in an audio decoding application.
It is easy to simply pick out the best type of crystal oscillator and say it is an improvement over what we are using - but is it really? Sure it is where it matters such as an accurate frequency counter, or even more so in something like a crystal analyzer or a device used to characterize oscillators.
About ovens. They are used to maintain the crystal at a very precise temperature to maintain an exact frequency. In digital audio reproduction, the exact frequency can be off a tiny amount without the possibility of hearing it. It is the short term change that is critical. We would call that wow and flutter on a turntable or cassette or open reel machine. So far in my experience, a good crystal oscillator doesn't require an oven type stability for audio use. They are stable enough as long as you don't stick them in front of a fan or beside something that generates heat. A clean DC supply voltage is also required for the circuit, which would normally be the DSP chip.
So there is some basic ground work for people to think about. In my view, an SC cut crystal in a double oven is total overkill, and also easily available as a custom frequency option (there is a reason why it isn't a stock item in the catalogues). So that technology is stable, mature and well known in the industry. They re expensive and run on two power supplies. One for the oven circuit, the other for the oscillator. A sine output is common.
-Chris
No level matching? There goes objectivity of test.
Sound measuring devices today can measure what you can hear and beyond.
What you've described is called anecdote, not evidence.
You won't be able to hear what the sound measuring devices today can pick up. Try -150 db noise for example or 30KHz.
Correct me if I'm wrong, since it's audio, the audible traits would be the main focus.Improve a digital audio product.
So far so good?
Next, a question, what does or did upgrading to Andrea's oscillator improve for audio?
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.
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?
Attachments
Correct, sorry for the error, "only" a 78dB gap to cover.
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...
Last edited:
Chris - as you don't know if a clock driving a DAC with -90dBc/Hz at 1 Hz is audible inferior one that is - 125dBc/Hz, doing the test that you suggest don't add one bit to the discussion at hand.
The only questions that is in need to be sorted out are as I see it:
1) Do the super clock performance reach the DAC? Indications are that it indeed does (earlier measurements - but lets make them totally conclusive)
2) Given the 1 is demonstrated, can a human really detect such minuscule differences that the difference of a bad clock, compared to a really good clock?
I feel everything else is just a diversion of the topic.
//
The only questions that is in need to be sorted out are as I see it:
1) Do the super clock performance reach the DAC? Indications are that it indeed does (earlier measurements - but lets make them totally conclusive)
2) Given the 1 is demonstrated, can a human really detect such minuscule differences that the difference of a bad clock, compared to a really good clock?
I feel everything else is just a diversion of the topic.
//
Last edited:
- Status
- Not open for further replies.