Oct 2, 2015 at 5:35 PM Post #361 of 27,084
   
 
Perhaps it's because USA dealers may not yet have concrete pricing on the DAC?
 
 
 
I'd relax about USA pricing, for a few weeks. All will be known quite soon, I'm sure. No point in getting wound-up, at this premature stage, until there is confirmation of pricing, either way. 
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Weak
 
Oct 2, 2015 at 6:10 PM Post #362 of 27,084
The US dealer I contacted confirmed that some dealers have already placed early orders (so there must be a price set) and that there's a likely a wait of a couple of months to get one, but he wasn't certain of the $13,000 price.
 
Oct 2, 2015 at 6:45 PM Post #363 of 27,084
  The US dealer I contacted confirmed that some dealers have already placed early orders (so there must be a price set) and that there's a likely a wait of a couple of months to get one, but he wasn't certain of the $13,000 price.


That price $13,000 sounds closer to the price of the British pound conversion then $16,300 I was quoted.
 
Oct 2, 2015 at 6:55 PM Post #364 of 27,084
  The US dealer I contacted confirmed that some dealers have already placed early orders (so there must be a price set) and that there's a likely a wait of a couple of months to get one, but he wasn't certain of the $13,000 price.

 
 
I don't doubt that there may be a trade listprice, but final retail price is often set nearer release date, partially taking into account the exchange rate at that point in time (and perhaps a bit of dealer 'politics' 
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)
 and not always in the customers' favour. We shall find out soon enough. For those who still wish to stress and gripe in the meantime, that's their prerogative.
 
 
Personally, I'm more interested in some in-depth reviews than I am in precise pricing, at this point in time.
 
Oct 2, 2015 at 9:38 PM Post #365 of 27,084
Very nice late-night-reading as always Rob
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Can you tell us a little of the clock in the DAVE would be very intresting, and how you feel it stands against the other ultra high end DAC's with space age Cesium clocks (Rubicon) / Crystal Femto galaxy clocks ?

/Fredrik

 
The issue of clocks is actually very complex, way more of a problem then in simply installing femto clocks. People always want a simple answer to problems even if the problem is multi-dimensional and complex. I will give you a some examples of the complexities of this issue.
 
Some years back a femto clock became available, and I was very excited about using it as it had a third of the cycle to cycle jitter of the crystal oscillators we were using. So I plugged it in, and listened to it. Unexpectedly, it sounded brighter and harder - completely the opposite of all the times I have listened to lower jitter. When you lower jitter levels in the master clock, it sounds smoother and warmer and more natural.
 
So I did some careful measurements, and I could see some problems.
 
The noise floor was OK, the same as before, and all the usual measurements were the same. But you could see more fringing on the fundamental, and this was quite apparent. Now when you do a FFT of say a 1 kHz sine wave, in an ideal world you would see the tone at 1 kHz and each frequency bucket away the output would be the systems noise floor. That is, you get a sharp single line representing the tone. But with a real FFT, you get smearing of the tone, and this is due to the windowing function employed by the FFT and jitter problems within the ADC, so instead of a single line you get a number of lines with the edges tailing of into the noise. This is known as side lobes or fringing. Now one normally calibrates the FFT and the instrument so you know what the ideal should be. Now with a DAC that has low frequency jitter, you get more fringing. Now I have spent many years on jitter and eliminating the effects of it on sound quality, and I know that fringing is highly audible, as I have done many listening tests on it. What is curious, is that it sounds exactly like noise floor modulation - so reduce fringing is the same as reducing noise floor modulation - they both subjectively sound smoother and darker with less edge and hardness.
 
So a clock that had lower cycle to cycle jitter actually had much worse low frequency jitter, and it was the low frequency jitter that was causing the problem and this had serious sound quality consequences. So a simple headline statement of low jitter is meaningless. But actually the problem is very much more complex than this.
 
What is poorly understood is that DAC architectures can tolerate vastly different levels of master clock jitter, and this is way more important than the headline oscillator jitter number. I will give you a few examples:
 
1. DAC structure makes a big difference. I had a silicon chip design I was working on some years back. When you determine the jitter sensitivity you can specify this - so I get a number of incoming jitter, and a number for the OP THD and noise that is needed. So initially we were working with 4pS jitter, and 120dB THD and noise. No problem, the architecture met this requirement as you can create models to run simulations to show what the jitter will do - and you can run the model so only jitter is changed, nothing else. But then the requirements got changed to 15 pS jitter. Again, no problem, I simply redesigned the DAC and then achieved these numbers. So its easy to change the sensitivity by a factor of 4 just by design of the DAC itself - something that audio designers using chips can't do.
 
2. DAC type has a profound effect on performance. The most sensitive is regular DSD or PDM, where jitter is modulation dependent, and you get pattern noise from the noise shaper degrading the output noise, plus distortion from jitter. R2R DAC's are very sensitive as they create noise floor modulation from jitter proportionate to the rate of change of signal (plus other problems due to the slow speed of switching elements). I was very concerned about these issues, and its one reason I invented pulse array, as the benefit of pulse array is that the error from jitter is only a fixed noise (using random jitter source with no low frequency problems). Now a fixed noise is subjectively unimportant - it does not interfere with the brains ability to decode music. Its when errors are signal dependent that the problems of perception start, and with pulse array I only get a fixed noise - and I know this for a fact due to simulation and measurements.
 
3. The DAC degrades clock jitter. What is not appreciated is that master clock jitter is only the start of the problem. When a clock goes through logic elements, (buffers level shifters, clock trees gates and flip-flops plus problem of induced noise)  every stage adds more jitter. As a rough rule of thumb a logic element adds 1 pS of more jitter. So a clock input of 1pS will degrade through the device to be effectively 4 pS once it has gone through these elements (this was the number from a device I worked on some years ago). So its the actual jitter on the DAC active elements that is important not the clock starting jitter. 
 
The benefit I have with Pulse Array is that the jitter has no sound quality degrading consequences - unlike all other architectures - as it creates no distortion or noise floor modulation. Because the clock is very close to the active elements (only one logic level away), the jitter degradation is minimal and there are no skirting issues at all. This has been confirmed with simulation and measurement - its a fixed noise, and by eliminating the clock jitter (I have a special way of doing this) noise only improves by a negligible 0.5 dB (127 dB to 127.5 dB). 
 
This is true of all pulse array DAC's even the simpler 4e ones. In short the jitter problem was solved many years ago, but I don't bleat on about it as its not an issue and because it's way too complex a subject to easily discuss.
 
I hope I have given a flavour here of some of the complexities.
 
Rob
 
Oct 2, 2015 at 10:28 PM Post #366 of 27,084
I had a hunch that you had addressed this problem in your own way Rob.

Thanks for you valuable contribution to this thread btw.
 
Oct 3, 2015 at 3:13 AM Post #367 of 27,084
after reading the japanse review , I want to see those 164000 taps !!
Thanks rob I can see you push the dac to it's limit with this awsome technology .
 
BTW what's the price in japan ?
 
Oct 3, 2015 at 3:16 AM Post #368 of 27,084
Well, I'm moving on, any company that doesn't want to tell it's potential customers it's price for it's product is pretty disrespectful. Even if they said, we don't know, that would be ok, but to totally ignore requests, forget it.
 
Oct 3, 2015 at 4:12 AM Post #369 of 27,084
  Well, I'm moving on, any company that doesn't want to tell it's potential customers it's price for it's product is pretty disrespectful. Even if they said, we don't know, that would be ok, but to totally ignore requests, forget it.

 
ever thought that the price hasn't been finalised yet hence why no-one has proffered a cost, if I knew I'd inform you but I can only quote the 'guestimate' from the beginning of the thread which is £8k... when DAVE 'testing' has been completed no doubt the final cost will be revealed, hth.
 
Oct 3, 2015 at 4:52 AM Post #370 of 27,084
OK GUY
Are you saying the price isn't even set in the UK yet? If so why did Chord inform the market it would be £7,995?
 
Oct 3, 2015 at 5:08 AM Post #371 of 27,084
OK GUY
Are you saying the price isn't even set in the UK yet? If so why did Chord inform the market it would be £7,995?

 
until I'm told the price of DAVE 'officially' I can only quote what has gone before, I can't even quote you a release date... yeah I know I'm unhelpful but it could be worse, whilst we wait things I'd recommend having a pie & a pint whilst watching the Rugby...
normal_smile .gif

 
Oct 3, 2015 at 5:09 AM Post #372 of 27,084
Raika
Is there any chance you would have the time to do a coherent translation of the Sound and Summary from that Japanese review of Dave?
 
Oct 3, 2015 at 5:43 AM Post #373 of 27,084
The issue of clocks is actually very complex, way more of a problem then in simply installing femto clocks. People always want a simple answer to problems even if the problem is multi-dimensional and complex. I will give you a some examples of the complexities of this issue.

Some years back a femto clock became available, and I was very excited about using it as it had a third of the cycle to cycle jitter of the crystal oscillators we were using. So I plugged it in, and listened to it. Unexpectedly, it sounded brighter and harder - completely the opposite of all the times I have listened to lower jitter. When you lower jitter levels in the master clock, it sounds smoother and warmer and more natural.

So I did some careful measurements, and I could see some problems.

The noise floor was OK, the same as before, and all the usual measurements were the same. But you could see more fringing on the fundamental, and this was quite apparent. Now when you do a FFT of say a 1 kHz sine wave, in an ideal world you would see the tone at 1 kHz and each frequency bucket away the output would be the systems noise floor. That is, you get a sharp single line representing the tone. But with a real FFT, you get smearing of the tone, and this is due to the windowing function employed by the FFT and jitter problems within the ADC, so instead of a single line you get a number of lines with the edges tailing of into the noise. This is known as side lobes or fringing. Now one normally calibrates the FFT and the instrument so you know what the ideal should be. Now with a DAC that has low frequency jitter, you get more fringing. Now I have spent many years on jitter and eliminating the effects of it on sound quality, and I know that fringing is highly audible, as I have done many listening tests on it. What is curious, is that it sounds exactly like noise floor modulation - so reduce fringing is the same as reducing noise floor modulation - they both subjectively sound smoother and darker with less edge and hardness.

So a clock that had lower cycle to cycle jitter actually had much worse low frequency jitter, and it was the low frequency jitter that was causing the problem and this had serious sound quality consequences. So a simple headline statement of low jitter is meaningless. But actually the problem is very much more complex than this.

What is poorly understood is that DAC architectures can tolerate vastly different levels of master clock jitter, and this is way more important than the headline oscillator jitter number. I will give you a few examples:

1. DAC structure makes a big difference. I had a silicon chip design I was working on some years back. When you determine the jitter sensitivity you can specify this - so I get a number of incoming jitter, and a number for the OP THD and noise that is needed. So initially we were working with 4pS jitter, and 120dB THD and noise. No problem, the architecture met this requirement as you can create models to run simulations to show what the jitter will do - and you can run the model so only jitter is changed, nothing else. But then the requirements got changed to 15 pS jitter. Again, no problem, I simply redesigned the DAC and then achieved these numbers. So its easy to change the sensitivity by a factor of 4 just by design of the DAC itself - something that audio designers using chips can't do.

2. DAC type has a profound effect on performance. The most sensitive is regular DSD or PDM, where jitter is modulation dependent, and you get pattern noise from the noise shaper degrading the output noise, plus distortion from jitter. R2R DAC's are very sensitive as they create noise floor modulation from jitter proportionate to the rate of change of signal (plus other problems due to the slow speed of switching elements). I was very concerned about these issues, and its one reason I invented pulse array, as the benefit of pulse array is that the error from jitter is only a fixed noise (using random jitter source with no low frequency problems). Now a fixed noise is subjectively unimportant - it does not interfere with the brains ability to decode music. Its when errors are signal dependent that the problems of perception start, and with pulse array I only get a fixed noise - and I know this for a fact due to simulation and measurements.

3. The DAC degrades clock jitter. What is not appreciated is that master clock jitter is only the start of the problem. When a clock goes through logic elements, (buffers level shifters, clock trees gates and flip-flops plus problem of induced noise)  every stage adds more jitter. As a rough rule of thumb a logic element adds 1 pS of more jitter. So a clock input of 1pS will degrade through the device to be effectively 4 pS once it has gone through these elements (this was the number from a device I worked on some years ago). So its the actual jitter on the DAC active elements that is important not the clock starting jitter. 

The benefit I have with Pulse Array is that the jitter has no sound quality degrading consequences - unlike all other architectures - as it creates no distortion or noise floor modulation. Because the clock is very close to the active elements (only one logic level away), the jitter degradation is minimal and there are no skirting issues at all. This has been confirmed with simulation and measurement - its a fixed noise, and by eliminating the clock jitter (I have a special way of doing this) noise only improves by a negligible 0.5 dB (127 dB to 127.5 dB). 

This is true of all pulse array DAC's even the simpler 4e ones. In short the jitter problem was solved many years ago, but I don't bleat on about it as its not an issue and because it's way too complex a subject to easily discuss.

I hope I have given a flavour here of some of the complexities.

Rob


Very interesting read Rob, even if im not an engineer i can understand the negs and the pros in each different DAC technology, with your fine explanation.

So to my noby questions:

So puls array are more resistant than a "Femto clock specced r2r clock is your conclution though you mesaurments, but how can i feel that the noise floor got lower when i conected the MSB Analog vs my Hugo, or is it just a illusion and i hear the more sharp sound signatur of the "femto" clock ?

So the puls array are very jitter resistant, but do you have the measured jitter specs of the QBD76 / Hugo / DAVE, that you can share with us, becaus its a jungle of diffrent USB / S/pdif recklocking devices that you can connect before the dac and have a claimed improvment to the sound.

But if you show us that it is no mening with does kind of products combined with Chord products we are glad to save the money for better purposes.

/ Fredrik
 
Oct 3, 2015 at 6:52 AM Post #374 of 27,084
  Audiophile reviews tend to be painfully pretentious and overly-verbose at the best of times, but when translated from Japanese to English, via google, the resulting mangled verbosity is enough to make me want to commit harakiri! 
confused_face.gif

 
 
Do we have any Japanese speakers in our midst, who could provide a more cogent English translation of the highlights of that review, please?
 
Thanks!

Hi, I'm a native Japanese living in Tokyo.
 
So I think I can give some of the key points from his review as follows.
Hope this helps you a bit!
 
====================
The sound
 - 1. The sound stage width and depth, clearness are significant.
 - 2. The musics from Dave are more dynamic compared with Hugo TT. The musics are very emotional.
 - 3. The sound resolution is much more improved. All of the sound details in the recording are presented at once.
 - 4. The sound is vivid, live and youthful. The sound is direct but very smooth at the same time.
 - 5. The sound is truly sharp like Katana blade.
 - Lastly, the dnyamic range is clealy more expanded.
For the headphone out, the sound from my HD650 Dmaa (recabled version with Oktavia) was exactly similar to the sound from TAD CE1 speakers using Chord poweramp.
If Dave is priced as over \3,000,000 ($25,000), I would say Nagra HD DAC + MPS is better, but the actual Dave price is just \1,500,000 ($12,500) and also we will need no pre-amplifier. So I would say that this DAC is overly low-priced. The satisfaction is too high for the price.
 

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