What kind of random jitter are you referring to? And if it affects the signal it will appear in an jtest, maybe not in an obvious way. Notwithstanting that most jitter is random. Deterministic jitter, if obvious, is bad if above a very low level and if present is a sign of incompetence in DAC implementation. Otherwise random phase noise or jitter is what you are dealing with and at some point you hit a floor. Implementation will certainly compromise the noise floor of any oscillator. The real question is at what level is it audible and how is it audible?
Close-in phase noise is essentially the same as random wow and flutter. There are standardized measurements for that with weighting curves to get a better correlation with what people hear. No doubt those are based on actual controlled listening tests done decades ago. Early CD player advertisements usually stated 'Wow and flutter: immeasurably small'.
The effect of phase noise at large frequency offsets depends a lot on the type of DAC. In a sigma-delta DAC, it can mix out-of-band quantization noise into the audio band.
The effect of phase noise at large frequency offsets depends a lot on the type of DAC. In a sigma-delta DAC, it can mix out-of-band quantization noise into the audio band.
I have been tinkering with DACs for over 20 years and frequently thought "this is it" but there always comes along something "better/different that I like more. Below a certain price point you just have to get the soldering iron out and apply the usual tricks.
With the rise of excellent performing one chip power supply solutions it has become easier for the average DIYer to achieve very good results with cheap Chinese boards.
The Chinese R2R boards are a novum for me and a real eye opener. How can they sound this good with such crappy power to the opamps and on top of that with just+-5V.
No attempt with AKM, ESS or TDA chips with discreete output stage or transformer coupling has given me this kind of 3D presentation and naturalness.
I wonder where clean power and adequate voltage will get me?
Klaus
With the rise of excellent performing one chip power supply solutions it has become easier for the average DIYer to achieve very good results with cheap Chinese boards.
The Chinese R2R boards are a novum for me and a real eye opener. How can they sound this good with such crappy power to the opamps and on top of that with just+-5V.
No attempt with AKM, ESS or TDA chips with discreete output stage or transformer coupling has given me this kind of 3D presentation and naturalness.
I wonder where clean power and adequate voltage will get me?
Klaus
Maybe you should measure besides listening. Everyone will agree stuff needs to sound good but ears are not exact instruments. How many times a worse measuring device was preferred in listening tests?
In the extremes (we like extremes) a device clearly not neutral is preferred by at least a few people in the group. It is just like that. Since I know this and dislike prejudice I have fooled groups a few times by having devices with totally unexpected contents that were preferred. Even before they were heard purely by looks and expectations 🙂 I did such one time with my 100 Euro Subbu in a beautiful cast aluminium casing with nice switches and LEDs just as a joke. It won. How many times a similar DAC in another casing was dismissed beforehand when it was announced what it was and what the DAC chip was without listening? So both ears and eyes can simply not be trusted and cold instruments without soul can be trusted more or less.
It makes no sense to debate this, many will not even care to look at graphs and stellar measurements. Understandable as some very good measuring devices are switched off after 15 minutes. This proves their point in their opinion and what can be said against that? When one is there and witnesses this one hears the same. Why spend 1000 Euro on a device that you dislike after 15 minutes? What when that 250 Euro SMSL is liked better? What if it simply is accepted as OK or very good within certain boundaries and extreme well measuring just is not noticed? What if we listen, like what we bought or achieved non-DIY/semi DIY/full DIY and the music and then measure to find the preferred device is only so so?
In the extremes (we like extremes) a device clearly not neutral is preferred by at least a few people in the group. It is just like that. Since I know this and dislike prejudice I have fooled groups a few times by having devices with totally unexpected contents that were preferred. Even before they were heard purely by looks and expectations 🙂 I did such one time with my 100 Euro Subbu in a beautiful cast aluminium casing with nice switches and LEDs just as a joke. It won. How many times a similar DAC in another casing was dismissed beforehand when it was announced what it was and what the DAC chip was without listening? So both ears and eyes can simply not be trusted and cold instruments without soul can be trusted more or less.
It makes no sense to debate this, many will not even care to look at graphs and stellar measurements. Understandable as some very good measuring devices are switched off after 15 minutes. This proves their point in their opinion and what can be said against that? When one is there and witnesses this one hears the same. Why spend 1000 Euro on a device that you dislike after 15 minutes? What when that 250 Euro SMSL is liked better? What if it simply is accepted as OK or very good within certain boundaries and extreme well measuring just is not noticed? What if we listen, like what we bought or achieved non-DIY/semi DIY/full DIY and the music and then measure to find the preferred device is only so so?
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btw for this price on discounts and with coins/coupons there is another R2R device with a more attractive appearance, even with shielded matrix and good regulators
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It would not be suprising many never go to concerts. That is today considered old fashioned.
Of course the chinese brands produce R2R DACs. That is the buzzword amongst grey audio men that simply buy on "R2R" and "class A" and believe the holy and absolute truth that sigma-delta and class D are not OK. Probably the brands engineers read this forum and ASR too.
So they produce both 😀
There are even audiophiles that believe discrete opamps in tower like construction are better than what the large IC manufacturers produce. About none of them measures equal or better than the current high performance opamps by the known brands. Still they are bought so they are produced.
Of course the chinese brands produce R2R DACs. That is the buzzword amongst grey audio men that simply buy on "R2R" and "class A" and believe the holy and absolute truth that sigma-delta and class D are not OK. Probably the brands engineers read this forum and ASR too.
So they produce both 😀
There are even audiophiles that believe discrete opamps in tower like construction are better than what the large IC manufacturers produce. About none of them measures equal or better than the current high performance opamps by the known brands. Still they are bought so they are produced.
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When you look at the spectrum of a clock signal with phase noise, you usually see noise skirts around the signal and a noise floor, and sometimes you see other aberrations such as noise bumps.
Those skirts are due to random fluctuations of the clock frequency. Those essentially cause wow and flutter, just like random variations in the speed of a turntable do.
The phase noise floor is related to random variations in length between a clock cycle and the rest. For example, when a sine wave is converted to a square wave by a slicer of which the threshold has some white noise on it, that will add to the phase noise floor.
The effect of the phase noise floor and any other phase noise at a distance greater than 100 kHz or so from the signal is usually worse in a sigma-delta DAC than in a multibit DAC with many bits, although it depends a lot on the DAC design.
I never tried to find out what exact research wow and flutter measurements are based on, but presumably vinyl records and analogue tape recorders, possibly also shellac records.
Important that we listen to the recording of that instrument.
How good do the DAC need to be to reproduce that recording.
I would say the standard measurements below -90dB and we are far below the distortions of the recording and the added distortion from DAC cant be heard.
But if the system with DAC has random artifacts, they are often heard and are irritating.
I have a TV that correct unsyncronasities with speeding up or down for a few seconds. So the sound is out of tune. The whole family laughs when that happens
But its not the DAC, its the system
30 years back I worked at a brodcaster. Then the analog circuits had to be -80 db so that the serial chain of circuits in the recording chain got below the spec limit of -60db
Btw alot of dollars in lundahl transformers in that chain. And some 2000 dollar microphones
Btw alot of dollars in lundahl transformers in that chain. And some 2000 dollar microphones
Random clock jitter impacts both noise skirts and noise floor. Nothing wrong in using J-Test signal provided the FFT size is large enough.
The problem with ASR J-Test graphs is the scale as close-in noise skirts are not properly visible in a graph of 20Hz to 20kHz. Altough most likely also the FFT size used in AP J-Test is not large enough for viewing close-in noise skirts.
Wow there's evem a Yun R2R at $26+. Like like or hate it there's no cheaper audio stuff than to buy China.
Good or bad is another matter in anycase its already a commercial product so how bad can it be. Lol
More like champagne and caviar. At that time the technical budget was huge and technology driven.
So a lot of tescam and sony brodcasting DATs.
And every high end microphone in the mic palet. Sony, neuman + lots of bruel and kjær
Thanks - so by "frequency offset", a change in frequency is ment - I never heard that denomination before. I'm used to the concept of jitter and wander and pn wrt non ideal clock freq/stability. Where jitter is deviations < 0,1UI and wander is >. I would interpret "frequency offset" as a wander. Offset in general meaning a "distance from nominal/reference" I suppose - but maybe you expressed this just in natural language and the term is not really a tech concept which I interpret it as!?
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If someone wants to know how to measure that the audio signal is being affected, they should probably study the whole thread at: https://www.diyaudio.com/community/threads/phase-noise-in-ds-dacs.387862/post-7063038 Probably the best discussion on it we have on around here.
Once it is understood how the signal is affected, then then it might make more sense to talk about what it does to the sound.
A couple of graphics to refer to at some point:
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I care less about buzzwords in audio.
There was a DAC technology that I hadn't tried yet because it has been to expensive in the past so I tried it when the price was right for me. Glad I did.
Same goes for discreete opamps. After hearing the difference between Opa1656 or 1612 and the Sparkos pro 2590 I care less about measurements because it's strikingly obvious that those measurements don't translate into sound quality. There is no contest and that's why Geshelli Labs partnered with Sparkos. These discreete stages transport their DACs into a league they can not reach with any ordinary opamp. At least not yet, but technology never stops evolving so who knows.
I don't know what makes a discreete stage sound more dynamic, real or why they deliver more depth information but I would be a fool to reject discreete opamps because measurements can't explain their superior music reproduction.
Many people have enjoyed the benefit of a good clock while the experts are still batteling over the nature of jitter.
Unless we try in real life what we deem to know in theory we will never find out 😉
It may become as obvious as the difference between €30 and €70 😎