[Kingwa]

Why the high had roll off?
The standard DAC design must had the analog filter.
For NOS DACs, they without digital filter, so they must design a much roll off analog filter, usually had -6 to -10DB at 20KHz, otherwise users maybe can hear the white noise " Sa..." at high .
In oversample DACs, nowdays the digital filter already had quite high performance, can reduced the noise to -110DB or more. But the D/A parts is working after the digital filter, the D/A parts bring the new noise ( I can't remember the noise name in English but who had interesting can find the article in web), in particular the ΣΔ  D/A chips , the noise is worst than the R2R D/A chips.
So for reduce the D/A noise, want to design a analog filter after the D/A.
The analog filter can't as the characteristic of digital filter, it usually had -6DB/oct or -12,-24DB/oct. Nowdays  usually applied -12DB/oct.
For the nice of frequency band, -12DB/oct can had less roll off at 20KHz but the phase characteristic is worst.
We like applied -6DB/oct for best phase characteristic but not best specs.

 

[Kingwa]

Why not compare the high end DACs instead the low end soundcard?
I find some low end digital/analog devices without analog filter. The Galaxy S definitely without analog filter from the diagram .
http://dl.project-voodoo.org/RMAA/reports/nfb-12-galaxys-voodoosound-load-hd650.htm
But I never experience a high end DAC without analog filter.
So a lot high end DACs are worst than the Galaxy S in frequency band.
 Members can find other high end DACs specs on web easier than me.
Although the NFB12 is a low end price gear, but its design is flow the high end DACs conformation. But I am not say its sound is high end.
There are some lot discusses at headfi before this discusses can read in the DAC19 and RE1 threads.
Some people experience the ΣΔ  D/A is noisy than the R2R D/A , I think because the D/A noise worst than R2R. So a analog filter is necessary for standard design and must careful to design.

 

[tim3320070]

Quote:

No
 
Quote:

Can everyone wait a couple of weeks before commenting? The gear needs run-in and initial impressions only muddy the water.
Stuck record here.

 

Yeah, apparently
 

 

[Kingwa]

What cause the roll off at NFB12.
The WM8741 setting is no fault at NFB12.
This  setting is  for accept 192KHz input.
The NFB12 can had better specs on page.The two caps in the red loops cause the roll off.
The NFB11 is same with the NFB12 except the digital parts and TWO caps.
In NFB11 we applied 100PF, but in NFB12 we applied 470PF.
An electronical university man can easy design a excellent specs gear. But the sound maybe not excellent.
We also can build a excellent specs gear, but we want more listen not only meter test.
In NFB11 we plan to design its sound very revealing, so we choice 100PF caps for it.
The NFB12 is finished design with NFB11 at same time, we want to design its sound a bit smooth , and forgive so we spend more days than NFB11 just for adjust parameter and listen, final choice the 470P.

For people who want better specs, you just simply replace these two caps by 100PF (or lower).
Sorry my poor English, I want to study English again, but I like listen musices and design PCB more than study English.

 

[tim3320070]

Isn't the HDP $450? Isn't the NFB12 $200? All/most comments are based on a handful of hours use? No wonder reviewers like Skylab are appreciated here, he lives with the gear for days/ weeks before rendering an opinion.

 

[tim3320070]

Quote:

What cause the roll off at NFB12.
The WM8741 setting is no fault at NFB12.
This  setting is  for accept 192KHz input.
The NFB12 can had better specs on page.The two caps in the red loops cause the roll off.
The NFB11 is same with the NFB12 except the digital parts and TWO caps.
In NFB11 we applied 100PF, but in NFB12 we applied 470PF.
An electronical university man can easy design a excellent specs gear. But the sound maybe not excellent.
We also can build a excellent specs gear, but we want more listen not only meter test.
In NFB11 we plan to design its sound very revealing, so we choice 100PF caps for it.
The NFB12 is finished design with NFB11 at same time, we want to design its sound a bit smooth , and forgive so we spend more days than NFB11 just for adjust parameter and listen, final choice the 470P.

For people who want better specs, you just simply replace these two caps by 100PF (or lower).
Sorry my poor English, I want to study English again, but I like listen musices and design PCB more than study English.

Kingwa- listen to english music, learn and enjoy at the same time.
 

 

[olor1n]

It would be helpful to get other impressions of how the NFB-12 couples with the HD650. I personally think there is great synergy between the two - the sound is full bodied, dynamic, and very musically engaging. Its done a nice job of brining out the fun personality out of the HD650s which apparently is a latent/hidden characteristic of these phones. FYI, I have the HD650s with new drivers which may explain why I'm not getting the veil with them. 
 
Quote:

I personally think the NFB-12 would be more suited for the K702, and NFB-11 more suited for the HD 650.

I prefer the Moon hdam installed in my Audio-GD Fun as it adds warmth and body to the sound signature. It's not as resolving as the more analytical Earth hdam, but I feel Moon has wonderful synergy with the HD650. It's energetic and engaging. Fwiw, I also have an HD650 with the "new" version drivers, with no "veil" in the first place, other than the less refined sound when not running off a dedicated amp and good source.

It's worth noting that people commenting on the NFB-12's unsuitability for the HD650 don't even have that headphone in their inventory.

 

[olor1n]

+ 1 to giving your Audio-GD gear time to burn in. All past/present owners of Audio-GD gear will testify to the effect long burn in has on their components.

 

[BoyNamedSue]

Good to see you on the forum Tim =).
 
 
Quote:

Originally Posted by tim3320070 /img/forum/go_quote.gif
 
Kingwa- listen to english music, learn and enjoy at the same time.
 

 

[haloxt]

I like reading people's early and burn-in impressions, so long as they don't do it crazy*carl style . If you don't know him Crazy*carl was a head-fier who (un)scientifically proved the sparrow and ipod sound identical .

 

[madwolf]

Quote:

What cause the roll off at NFB12.
The WM8741 setting is no fault at NFB12.
This  setting is  for accept 192KHz input.
The NFB12 can had better specs on page.The two caps in the red loops cause the roll off.
The NFB11 is same with the NFB12 except the digital parts and TWO caps.
In NFB11 we applied 100PF, but in NFB12 we applied 470PF.
An electronical university man can easy design a excellent specs gear. But the sound maybe not excellent.
We also can build a excellent specs gear, but we want more listen not only meter test.
In NFB11 we plan to design its sound very revealing, so we choice 100PF caps for it.
The NFB12 is finished design with NFB11 at same time, we want to design its sound a bit smooth , and forgive so we spend more days than NFB11 just for adjust parameter and listen, final choice the 470P.

For people who want better specs, you just simply replace these two caps by 100PF (or lower).
Sorry my poor English, I want to study English again, but I like listen musices and design PCB more than study English.

Thanks for the detail explaination. The DAC section is indeed design Correctly. With the oversampling filter set to 96 Khz I could hear background hiss at high volume.
That mean that everything is converted to 192 before going to the DAC.
 
Reverting the modification I have done.
 
+2 for KingWa  

 

[olor1n]

Quote:

I like reading people's early and burn-in impressions, so long as they don't do it crazy*carl style . If you don't know him Crazy*carl was a head-fier who (un)scientifically proved the sparrow and ipod sound identical .

Lol. I remember reading crazycarl's posts when I had zero experience with amps and dacs. He did raise some doubts but boy was he wrong. I guess I should be thankful to him though, as he did inadvertently teach me to never take anyone's words as gospel around these parts. Try things for yourself and go from there.

 

[madwolf]

Question still remain. 
 
1) If the roll off is indeed cause by the filter design after the DAC it should affect all the graph for 44khz, 96khz and 192khz 
 
From the graph by suprecurio it only affect the 44khz and 96khz and not the 192khz. 
 
So something is missing here. 

 

[Slaughter]

Chill out Tim. I posted initial impression which are done on this forum every day and then I updated after a good amount of burn in. And remember, these come from the factory with 100 hours on them already, so we are not talking about brand new gear. It's funny on this forum because burn in is always longer than what someone has on it. If I say I have 300 hours, someone always comes along and says it needs 400. If I have 400, it needs 500. People like to know what something is going to sound like when they get it. It helps with any initial disappointment and buyers remorse. 

 
Quote:

Isn't the HDP $450? Isn't the NFB12 $200? All/most comments are based on a handful of hours use? No wonder reviewers like Skylab are appreciated here, he lives with the gear for days/ weeks before rendering an opinion.

 

[olor1n]

Quote:

Chill out Tim. I posted initial impression which are done on this forum every day and then I updated after a good amount of burn in. And remember, these come from the factory with 100 hours on them already, so we are not talking about brand new gear. It's funny on this forum because burn in is always longer than what someone has on it. If I say I have 300 hours, someone always comes along and says it needs 400. If I have 400, it needs 500. People like to know what something is going to sound like when they get it. It helps with any initial disappointment and buyers remorse. 

 
Quote:

Isn't the HDP $450? Isn't the NFB12 $200? All/most comments are based on a handful of hours use? No wonder reviewers like Skylab are appreciated here, he lives with the gear for days/ weeks before rendering an opinion.

Views on burn in for Audio-GD gear are pretty consistent though. Have you owned any of their gear before or read any of the other threads for their other gear? Not being accusatory here, just curious.