They say it does cross-correlation, but to what minimum offset frequency I don't see. Is it down to 0.1Hz offset like some of the other cross-correlation analyzers?
My clocks are already measured by such equipment, but it doesn't work for dac audio outputs. Not according to what Enrico Rubiola claims anyway.
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I have to disagree. Standard oscillators spec jitter out at 12kHz offset and above. Easy to get impressive numbers if you don't count more close-in offset frequencies where most of the jitter is. Those clocks are recommended for certain types of communication systems, not for audio dacs. For around $8 (less in quantities) one can buy NDK SDA series clocks which are far better than standard clocks, yet IMHO and IME still nothing to write home about.
Mark,
Look again at the stability of a crystal oscillator. I measured these with an HP 5072A, and still have it. High stability time base option included. Communications systems have far tighter requirements than audio anything. I worked in that industry with T1/PRI circuits, and SIP connections.
I'm going to recommend you read the data sheets for these things, and understand them.
Look again at the stability of a crystal oscillator. I measured these with an HP 5072A, and still have it. High stability time base option included. Communications systems have far tighter requirements than audio anything. I worked in that industry with T1/PRI circuits, and SIP connections.
I'm going to recommend you read the data sheets for these things, and understand them.
No. What has tight specs are GPS clocks in satellites. The best audio clocks are very similar to that.
Once again, communication systems are concerned with bit errors. Bits are pretty resilient, either high or low. Eye patterns can be used with scopes.
OTOH, phase noise is analog not digital. Dacs care about the analog part. According to Marcel as little as a few ps jitter at standard dac clock frequencies. And that's in the 1Hz to 10Hz offset band. Not at 12kHz and above.
Here is a phase noise plot of an SOA audio dac clock (notice the audio dac frequency):
-140dBc/Hz at 10Hz offset. Now that's a good clock. Hitting -150 or -160dBc at 12kHz is meaningless for a dac clock, but that's something you might get from a standard clock. Unfortunately the phase noise climbs up fast into 1/f region in those clocks. At those very close-in offset frequencies below 10Hz offset standard clocks are worse than the opamps or anything else in the dac.
The problem is that the difference doesn't show up well on an FFT. But you sure can hear it, and that includes for hardcore skeptics.
Once again, communication systems are concerned with bit errors. Bits are pretty resilient, either high or low. Eye patterns can be used with scopes.
OTOH, phase noise is analog not digital. Dacs care about the analog part. According to Marcel as little as a few ps jitter at standard dac clock frequencies. And that's in the 1Hz to 10Hz offset band. Not at 12kHz and above.
Here is a phase noise plot of an SOA audio dac clock (notice the audio dac frequency):
-140dBc/Hz at 10Hz offset. Now that's a good clock. Hitting -150 or -160dBc at 12kHz is meaningless for a dac clock, but that's something you might get from a standard clock. Unfortunately the phase noise climbs up fast into 1/f region in those clocks. At those very close-in offset frequencies below 10Hz offset standard clocks are worse than the opamps or anything else in the dac.
The problem is that the difference doesn't show up well on an FFT. But you sure can hear it, and that includes for hardcore skeptics.
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Ugh! Another REALLY loud piece of test equipment. I'm surprised that after seven years of that you can hear anything. You are a tough man!
My GPS disciplined frequency reference is put in holdover mode when I measure crystal oscillator stability. They sometimes have frequency jumps as they correct. I use three GPS reference clocks and an HP 5087A distribution amplifier (rebuilt).
Audio clocks are nowhere near the stability of the clocks used in the GPS constellation. What are you smoking here! Besides, what counts in audio is short term stability. Long term stability matters not, especially with the drift rates a garden variety crystal oscillator has. I've studied clocks for digital audio. Then you have the encoded frequency errors when the signal was digitized to begin with. If they are enough to worry about, you're sunk, permanently encoded. Given I worked in recording studios .. Protools ran on a computer. Digital recorders used crystal oscillators, not in an oven. They were more than stable enough. Basic quality test equipment uses temperature controlled crystal oscillators, really good ones are ST cut in a double oven. This is far better than any audio digitizer (or was, I'm sure someone might be as good these days).
Audio electronics is simply not as good as what you see in test equipment depending on the use and circuit. For frequency, test equipment is far more stable.
Audio clocks are nowhere near the stability of the clocks used in the GPS constellation. What are you smoking here! Besides, what counts in audio is short term stability. Long term stability matters not, especially with the drift rates a garden variety crystal oscillator has. I've studied clocks for digital audio. Then you have the encoded frequency errors when the signal was digitized to begin with. If they are enough to worry about, you're sunk, permanently encoded. Given I worked in recording studios .. Protools ran on a computer. Digital recorders used crystal oscillators, not in an oven. They were more than stable enough. Basic quality test equipment uses temperature controlled crystal oscillators, really good ones are ST cut in a double oven. This is far better than any audio digitizer (or was, I'm sure someone might be as good these days).
Audio electronics is simply not as good as what you see in test equipment depending on the use and circuit. For frequency, test equipment is far more stable.
It's been a decade since I last sat in front of the E5052, so I don't remember. You can disable the crosscorrelation if you don't like it.
Sure. That's because that's relevant for the RF applications those oscillators go into.
I characterized the oscillators I designed down to 10 Hz offset. I'd usually report 10 Hz - 12 kHz integrated jitter and 100 Hz - 12 kHz integrated jitter. If I recall correctly, the 10 Hz - 12 kHz was around a picosecond give/take. The 100 Hz to 12 kHz number was around 200 fs. The oscillator core had four transistors and a resistor in it. Not complicated.
And I'm not suggesting that the oscillator I designed would be the world's best today, but it was darned good then. Certainly better than what you'd need for audio. Also, just because you can get lower noise doesn't mean that lower noise is needed. If you're using an ESS DAC the first thing the clock sees is a clock-jitter cleaner. Anyone who understands how those work will understand how ridiculous the femto-second clocks are for audio.
Anyway. I think we're starting to beat the stain where the dead horse used to be. Can we get back to FFTs and multi-tone analyses?
Tom
I'm not using that. But, yeah there is an ASRC in there which can be turned off. When turned on the ASRC uses the crystal MCLK as a reference.
Maybe more to the point (or my point anyway), of the people who have so far built Marcel's discrete RTZ dac, and who use it with Cestrian's clock and reclocker board, users usually start out with NDK SDA and or Crystek 957 clocks. First thing they find is that NDK SDA in Cestrian's board sound better than the same clock built into the I2SoverUSB USB to I2S bus board. No surprise since the USB board buffers the clocks in a CPLD.
Next step up are Iancanada SC Pure clocks, which are SC cut crystal-based but not in an oven. They take almost a week to fully settle in. Then when people try going back to Crystek, they can hear the loss of SQ and they don't like going back. However, they also don't like cost difference going to Crystek to SC Pure. Next step after SC Pure are Andrea Mori oscillators with my own design squaring board. Top step are Acko SOA SC cut, temperature controlled, SOA measured phase noise oscillators. Again, I use my own squaring circuit. There are audible differences at each step, but SC Pure are livable enough for most folks after hearing all the different options. Going back to Crystek is hard though. Now its clear there were always distorted sounding and ugly artifacts.
The interesting thing about this is that almost nobody expects the SC Pure clocks will be worth trying, and they cost too much anyway. When people do try them and after the clocks settle in, they always say they hadn't expected much difference in sound. They didn't know better sound was possible. Only after you hear it do you know. And the skeptics here haven't heard it, so I don't take them too seriously when they argue from theory that better clocks can't matter for audio.
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Yup, you got me, SC cut. Damned keyboard. I'm not kidding, drives me nuts, smaller size and sensitive keys. It's new and I'm, too cheap to throw it out.
Anyway, the entire point is, you're talking about stuff audio doesn't need and wouldn't make any difference. I made that point abundantly clear. You can make the clock as clean as you want, it won't matter past a certain point, period. That and you only care about short term stability here, why is that so hard to understand???? In addition, the data has permanently encoded into it the jitter of the digitizing system.
The only thing that matters is excessive noise and short term stability problems. We'll assume they got the frequency right. A normal crystal is more than stable enough, better than ceramic resonators but some of those might be more than good enough. The worst would be a GPS disciplined system as it corrects occasionally in a step function. That would be for long term stability anyway, and your absolute frequency accuracy just ain't that important considering normal crystal drift with time. You simply will not hear it. Not ever.
The settling time for a stone cold double oven oscillator is a week at most. A crystal outside an oven will never settle. Not ever. Also, if you look at the short term stability of these oscillators as they settle, it isn't that different from settled in an oven. What you have here are reports that depend on what those folks are thinking. Never mind you couldn't tell the difference anyway.
Mark, learn, understand, speak factually. It'll help. What you just presented is garbage. All you proved was those observers are highly susceptible to suggestion. That's all, easily disproved in real testing.
Anyway, the entire point is, you're talking about stuff audio doesn't need and wouldn't make any difference. I made that point abundantly clear. You can make the clock as clean as you want, it won't matter past a certain point, period. That and you only care about short term stability here, why is that so hard to understand???? In addition, the data has permanently encoded into it the jitter of the digitizing system.
The only thing that matters is excessive noise and short term stability problems. We'll assume they got the frequency right. A normal crystal is more than stable enough, better than ceramic resonators but some of those might be more than good enough. The worst would be a GPS disciplined system as it corrects occasionally in a step function. That would be for long term stability anyway, and your absolute frequency accuracy just ain't that important considering normal crystal drift with time. You simply will not hear it. Not ever.
The settling time for a stone cold double oven oscillator is a week at most. A crystal outside an oven will never settle. Not ever. Also, if you look at the short term stability of these oscillators as they settle, it isn't that different from settled in an oven. What you have here are reports that depend on what those folks are thinking. Never mind you couldn't tell the difference anyway.
Mark, learn, understand, speak factually. It'll help. What you just presented is garbage. All you proved was those observers are highly susceptible to suggestion. That's all, easily disproved in real testing.
TCXOs have largely replaced OCXOs now. They offer similar performance to yesteryear's OCXOs without the need to wait forever for them to warm up.
Not thereby said that you can't wreck their performance with crappy design. Incompetence knows no borders.
And the fancy oscillators aren't needed in audio. It's not a bad place to geek out. That can be fun. But it won't make a lick of difference in the analog waveform. They make for good marketing bullet points, though.
Tom
Not thereby said that you can't wreck their performance with crappy design. Incompetence knows no borders.
And the fancy oscillators aren't needed in audio. It's not a bad place to geek out. That can be fun. But it won't make a lick of difference in the analog waveform. They make for good marketing bullet points, though.
Tom
Sure, everyone knows that. Until the hear the difference, then they all say they didn't expect it to make a difference. I'll leave off here unless someone wants to visit Auburn and see for themselves.
Hi Mark,
Okay enough. Anecdotal hear-say that is very easily disproved in theory and by even half competent testing.
Yup, my ring of friends disproves everything that has been proved in industry and everything else. Just perfect. You can be dead wrong and still hold onto garbage "science". Now we have ears with better resolution than high end test equipment. I have an idea, how about having NASA and the military hire that group to increase the accuracy of radar and GPS location services? Do you have any iodea what that group of gifted individuals are worth? My god, they must be protected at all costs!
Honestly Mark, use your head.
Hi Tom,
Yes. TCXO units are very good. I haven't compared them yet as for noise. But as long as the temperature curve is properly measured and characterized there is no reason why they shouldn't be stable. I just didn't want to open that can of worms with Mark here.
Okay enough. Anecdotal hear-say that is very easily disproved in theory and by even half competent testing.
Yup, my ring of friends disproves everything that has been proved in industry and everything else. Just perfect. You can be dead wrong and still hold onto garbage "science". Now we have ears with better resolution than high end test equipment. I have an idea, how about having NASA and the military hire that group to increase the accuracy of radar and GPS location services? Do you have any iodea what that group of gifted individuals are worth? My god, they must be protected at all costs!
Honestly Mark, use your head.
Hi Tom,
Yes. TCXO units are very good. I haven't compared them yet as for noise. But as long as the temperature curve is properly measured and characterized there is no reason why they shouldn't be stable. I just didn't want to open that can of worms with Mark here.
Well... It seems to me that if the (effective) conversion clock has modulation on it, that modulation will be imposed on all the tones the DAC generates. The entire waveform is modulated. That correct?
That modulation could be amplitude modulation or phase modulation. Or, both.
Now what effect would phase modulation of the entire waveform as applied to a loudspeaker have on the sonic characteristics of the acoustic output of the loudspeaker? (I'm asking - not leading the witnesses or baiting, so to speak.)
Would this waveform modulation be shown in a typical FFT based display? Not, is it possible to show, but is it actually shown? Or, would demodulation of the phase modulation waveform be needed first? (Again - asking, not baiting.)
That modulation could be amplitude modulation or phase modulation. Or, both.
Now what effect would phase modulation of the entire waveform as applied to a loudspeaker have on the sonic characteristics of the acoustic output of the loudspeaker? (I'm asking - not leading the witnesses or baiting, so to speak.)
Would this waveform modulation be shown in a typical FFT based display? Not, is it possible to show, but is it actually shown? Or, would demodulation of the phase modulation waveform be needed first? (Again - asking, not baiting.)
If the DAC clock wanders you'd get spectral leakage in the FFT. I'd expect that you'd get spurious tones if you modulated the clock with a fixed frequency. But I can't think of any reason you'd do that.
I can see a scenario where the clock would be amplitude modulated. That can happen if the oscillator runs from a noisy power supply. The fix is easy: Use a quiet supply. It's easy to test for. It's usually immediately obvious in the phase noise plot and would like result in higher spectral leakage (taller grass) in the FFT as it increases the jitter of the clock.
Both of these fall under "design the circuit competently" in my view.
It's exceptionally difficult to get a crystal to oscillate at a frequency that's slightly off its resonance frequency, so if you want to frequency or phase modulate such an oscillator you really have to try at it. The high Q of the crystal ensures this. This does require that the designer of the oscillator has added the appropriate load capacitance on the crystal, however. That falls under competent design. It's easy to get the XO to run at a frequency that's slightly off if you don't have the correct load capacitance. 🙂
There are some crystal cuts that are used for overtone crystals. These crystals are intended to run at some multiple of their harmonic, and it is possible for such crystals to oscillate at the wrong frequency. It's up to the designer of the oscillator to ensure that the oscillator starts up at the correct frequency in that case (see my note about competent design).
The AT cut crystals common for the 12.288 MHz, 24.576 MHz, and 33.8688 MHz that are commonly used in audio DACs and ADCs are pretty difficult to get to act up.
The various crystal parameters (Q, ESR, resonance frequency (or frequencies for an overtone crystal) are easy to measure. Some network analyzers will do this. There's also a crystal analyzer. Last I checked, Sounders had that corner of the market. Some 12ish years ago their analyzers sold for about $5600, which is practically free in the test & measurement world. 🙂
Tom
I can see a scenario where the clock would be amplitude modulated. That can happen if the oscillator runs from a noisy power supply. The fix is easy: Use a quiet supply. It's easy to test for. It's usually immediately obvious in the phase noise plot and would like result in higher spectral leakage (taller grass) in the FFT as it increases the jitter of the clock.
Both of these fall under "design the circuit competently" in my view.
It's exceptionally difficult to get a crystal to oscillate at a frequency that's slightly off its resonance frequency, so if you want to frequency or phase modulate such an oscillator you really have to try at it. The high Q of the crystal ensures this. This does require that the designer of the oscillator has added the appropriate load capacitance on the crystal, however. That falls under competent design. It's easy to get the XO to run at a frequency that's slightly off if you don't have the correct load capacitance. 🙂
There are some crystal cuts that are used for overtone crystals. These crystals are intended to run at some multiple of their harmonic, and it is possible for such crystals to oscillate at the wrong frequency. It's up to the designer of the oscillator to ensure that the oscillator starts up at the correct frequency in that case (see my note about competent design).
The AT cut crystals common for the 12.288 MHz, 24.576 MHz, and 33.8688 MHz that are commonly used in audio DACs and ADCs are pretty difficult to get to act up.
The various crystal parameters (Q, ESR, resonance frequency (or frequencies for an overtone crystal) are easy to measure. Some network analyzers will do this. There's also a crystal analyzer. Last I checked, Sounders had that corner of the market. Some 12ish years ago their analyzers sold for about $5600, which is practically free in the test & measurement world. 🙂
Tom
Yes, "pulling" a crystal to lock to another source isn't easy. They want to resonate at their natural frequency and basically were known for the lowest phase noise source. As long as you don't overdrive the thing, you should be good.
Modulating clocks is a way to reduce noise for EMI, "spread spectrum". You wouldn't use a crystal for that clock.
CG, yes. If your clock source is noisy it will modulate anything locked to it. But it has to be incredibly bad, and for a crystal that means broken (defective, needs fixing). Standard mixer principles. This is the argument being grossly exaggerated by some who ignore reality.
Modulating clocks is a way to reduce noise for EMI, "spread spectrum". You wouldn't use a crystal for that clock.
CG, yes. If your clock source is noisy it will modulate anything locked to it. But it has to be incredibly bad, and for a crystal that means broken (defective, needs fixing). Standard mixer principles. This is the argument being grossly exaggerated by some who ignore reality.
Some comments from people who have tried better clocks with a Marcel RTZ dac:
-------------------------
Cestrian very kindly sent me one of his SC-Pures to try out in the reclocker board , I’ve had it warming up for 12+ hours . I found the sound to be quite smooth and wide at first, it then seemed to get noticeably deeper with increased reverberation with things like piano.
I think with the Crysteks the sound is a little more stale with more artefacts , certainly not as expansive soundstage as the SC-Pure and bass doesn’t seem to reach as low .
I need to spend more time with it and then go back to the Crysteks and NDK’s , so far though it’s looking like I may have to purchase one of these at some point . Unfortunately I have no way to test this so can only post what I’m hearing so take it or leave it.
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-7999504
----------------------------
I’ve just taken delivery of some SC Pure crystals. The RTZ DAC with the reclocker board sounded great already with the Crysteks, but I’m going to have to wait for the SC’s to run in for a bit…..
This is the best DAC by far that I have ever had in my system.
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-8002796
------------------
I've put the Crystek back in and gave it time to warm up,I've got to be honest it's now hard going back to it . The Crystek now reminds me of those early Bitstream CDP's , a sort of artificial flavour added . The SC Pure is better balanced with less digital glare , soundstage and depth better with the SC Pure. It makes it hard doing a blind test because the time required for the XO's to warm up which the SC Pure definitely needs . I have just fitted the NDK's so will see how they are after a warm up.
I've not ordered the SC Pure yet , I want to be sure first although must admit I'm not enjoying the Crysteks as much now . Dare I ask what else to try ?
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-8008987
--------------------------
I was going to post this earlier, but I waited until Leon responded first.
Thought I would share some feedback from first listen to the SC Pure crystals on the reclocker board. Usual “to my ears” disclaimers apply : - I had the SC Pure XOs on for about 8 hours continuously before I gave in and had to have a listen. Source was 44.1kHz WAV files, HQ Player on the fly DSD256 conversion.
There was a definite and obvious improvement over the Crystek XOs. The first thing I noticed was that the weight and solidity of everything was much better. Bass was certainly weightier, but also tighter. All instruments and voices now have even more space around them. The word “grip” also kept coming to mind. I listen to quite a bit of symphonic power metal (Nightwish) which can get demanding and easily descends into a mush when it gets intense. Not so here. Control over everything was maintained, whatever I threw at it. The extra grip and control also allows everything else to come through with greater clarity. Percussion instruments were also given a wider space to play in, giving more insight into the sound of each instrument and it’s timbre, decay etc.
Everything seems to be more coherent and “hangs” together better and more evenly if that makes sense.
I’m looking forward to seeing how running in of the SC Pures develops over time, but looks like the admittedly pricey gamble has paid off.
I’m chuffed to bits!
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-8009041
------------------
The other thing I wanted to talk about is effects of using various S-cut crystal oscillators/clocks. Three types have been tried by me. They are Acko, Andrea Mori DRIXO (without doublers), and SC Pure. .
What I will say next is going to be purely subjective, so be forewarned: The three types of clocks all sound a little bit different from other, at least to me and the other listeners here using the reproduction system with Sound Lab electrostatic speakers. The most detailed and probably the most accurate sounding clock oscillators are Acko but there are some possible downsides. First, they are the most expensive by far; second, they are very revealing of recording's SQ. Great recordings sound excellent, but flaws in many recording are easily audible. Next are the DRIXO clocks with 22/24MHz crystals (as the RTZ dac would be sensitive to the use of doublers). The DRIXO oscillators are to my ears, at least if using my squaring board, somewhere between Acko and SC Pure. SC Pure are next in line. I would say they sound excellent/superior compared the best consumer market clocks I have listened to with this dac (Crystek 957, and NDK SDA). To me SC Pure are great for casual listening and much more forgiving of less than nearly perfect recordings (as compared to Acko). They are also the most affordable of SC-cut crystal clocks. The downside is that they lack some of the soundstage depth and openness of the Acko clocks (where open sound is kind of like having some "empty or black space" separating instrument sounds from each other at low levels, and also having some more ability to provide clear low level reverberation tail fadeouts and little reflection details). At least some of what I subjectively report hearing in this paragraph are things which I don't believe there is any good, meaningful, practical way to measure at this point in time. Again, please take note this clock paragraph is entirely subjective and in my own opinion.
https://www.diyaudio.com/community/threads/general-purpose-dac-clock-board.413001/post-7979963
--------------------
My comments for this thread:
There has been other feedback from people trying better clocks with Marcel's RTZ dac, some of it is by PM or email, mostly because people don't want to told they are crazy and hallucinating by theoretician types such as those in this thread who can't be bothered to listen. To me at least, what those latter people say is in some ways like what the flat earthers say, which is: I know I'm right so I don't have to listen to arguments or information to the effect that the earth is round because I already know its flat. This is what I have to say to them: Marcel's dac is not an ESS dac nor an AKM dac. Its outside the experience of the guys who are sure clocks can have no effect. I know they will not be persuaded by any of the above, but other readers of this thread might want to consider there are people who are not crazy nor hallucinating who have actually taken time to listen despite being skeptical at first that clocks could make any difference. In this case the experimentalists are right and the overconfident theoreticians are wrong. That's the way I see it. And now, we can probably expect to hear more of the same "clocks can't make any difference" arguments.
-------------------------
Cestrian very kindly sent me one of his SC-Pures to try out in the reclocker board , I’ve had it warming up for 12+ hours . I found the sound to be quite smooth and wide at first, it then seemed to get noticeably deeper with increased reverberation with things like piano.
I think with the Crysteks the sound is a little more stale with more artefacts , certainly not as expansive soundstage as the SC-Pure and bass doesn’t seem to reach as low .
I need to spend more time with it and then go back to the Crysteks and NDK’s , so far though it’s looking like I may have to purchase one of these at some point . Unfortunately I have no way to test this so can only post what I’m hearing so take it or leave it.
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-7999504
----------------------------
I’ve just taken delivery of some SC Pure crystals. The RTZ DAC with the reclocker board sounded great already with the Crysteks, but I’m going to have to wait for the SC’s to run in for a bit…..
This is the best DAC by far that I have ever had in my system.
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-8002796
------------------
I've put the Crystek back in and gave it time to warm up,I've got to be honest it's now hard going back to it . The Crystek now reminds me of those early Bitstream CDP's , a sort of artificial flavour added . The SC Pure is better balanced with less digital glare , soundstage and depth better with the SC Pure. It makes it hard doing a blind test because the time required for the XO's to warm up which the SC Pure definitely needs . I have just fitted the NDK's so will see how they are after a warm up.
I've not ordered the SC Pure yet , I want to be sure first although must admit I'm not enjoying the Crysteks as much now . Dare I ask what else to try ?
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-8008987
--------------------------
I was going to post this earlier, but I waited until Leon responded first.
Thought I would share some feedback from first listen to the SC Pure crystals on the reclocker board. Usual “to my ears” disclaimers apply : - I had the SC Pure XOs on for about 8 hours continuously before I gave in and had to have a listen. Source was 44.1kHz WAV files, HQ Player on the fly DSD256 conversion.
There was a definite and obvious improvement over the Crystek XOs. The first thing I noticed was that the weight and solidity of everything was much better. Bass was certainly weightier, but also tighter. All instruments and voices now have even more space around them. The word “grip” also kept coming to mind. I listen to quite a bit of symphonic power metal (Nightwish) which can get demanding and easily descends into a mush when it gets intense. Not so here. Control over everything was maintained, whatever I threw at it. The extra grip and control also allows everything else to come through with greater clarity. Percussion instruments were also given a wider space to play in, giving more insight into the sound of each instrument and it’s timbre, decay etc.
Everything seems to be more coherent and “hangs” together better and more evenly if that makes sense.
I’m looking forward to seeing how running in of the SC Pures develops over time, but looks like the admittedly pricey gamble has paid off.
I’m chuffed to bits!
https://www.diyaudio.com/community/...2soverusb-pcm2dsd-rtz-dac.423401/post-8009041
------------------
The other thing I wanted to talk about is effects of using various S-cut crystal oscillators/clocks. Three types have been tried by me. They are Acko, Andrea Mori DRIXO (without doublers), and SC Pure. .
What I will say next is going to be purely subjective, so be forewarned: The three types of clocks all sound a little bit different from other, at least to me and the other listeners here using the reproduction system with Sound Lab electrostatic speakers. The most detailed and probably the most accurate sounding clock oscillators are Acko but there are some possible downsides. First, they are the most expensive by far; second, they are very revealing of recording's SQ. Great recordings sound excellent, but flaws in many recording are easily audible. Next are the DRIXO clocks with 22/24MHz crystals (as the RTZ dac would be sensitive to the use of doublers). The DRIXO oscillators are to my ears, at least if using my squaring board, somewhere between Acko and SC Pure. SC Pure are next in line. I would say they sound excellent/superior compared the best consumer market clocks I have listened to with this dac (Crystek 957, and NDK SDA). To me SC Pure are great for casual listening and much more forgiving of less than nearly perfect recordings (as compared to Acko). They are also the most affordable of SC-cut crystal clocks. The downside is that they lack some of the soundstage depth and openness of the Acko clocks (where open sound is kind of like having some "empty or black space" separating instrument sounds from each other at low levels, and also having some more ability to provide clear low level reverberation tail fadeouts and little reflection details). At least some of what I subjectively report hearing in this paragraph are things which I don't believe there is any good, meaningful, practical way to measure at this point in time. Again, please take note this clock paragraph is entirely subjective and in my own opinion.
https://www.diyaudio.com/community/threads/general-purpose-dac-clock-board.413001/post-7979963
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My comments for this thread:
There has been other feedback from people trying better clocks with Marcel's RTZ dac, some of it is by PM or email, mostly because people don't want to told they are crazy and hallucinating by theoretician types such as those in this thread who can't be bothered to listen. To me at least, what those latter people say is in some ways like what the flat earthers say, which is: I know I'm right so I don't have to listen to arguments or information to the effect that the earth is round because I already know its flat. This is what I have to say to them: Marcel's dac is not an ESS dac nor an AKM dac. Its outside the experience of the guys who are sure clocks can have no effect. I know they will not be persuaded by any of the above, but other readers of this thread might want to consider there are people who are not crazy nor hallucinating who have actually taken time to listen despite being skeptical at first that clocks could make any difference. In this case the experimentalists are right and the overconfident theoreticians are wrong. That's the way I see it. And now, we can probably expect to hear more of the same "clocks can't make any difference" arguments.
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