[madwolf]

udial is a file that consists of 3 sine tone 
2 at the lower frequency much like a tone of a tone dial tone. Everyone would not have problem hearing this 
the other tone is a 19khz tone which is at least 4 times the amplitude. 
 
most people would hear the tone at the lower frequency but the 19Khz would be heard at a very soft note prompting user to up the volume.
This kind of high frequency is very rare in real life, but is very harmful to your speaker or headphone.
If the amplifier is clipping it could generate lots of harmful harmonics at high power which might burn your tweeter and yet people might think it is soft
because it is at the limit of human hearing ability.
 
So if you want to try this tone use a cheap headphone or speaker.  
 
Supercurio is refering to a reflection of the tone cause by a "musical" configuration of the NFB-12. 
Maybe the diagram from him is a bit hard to understand 
I did a waterfall using the NFB12 with it original configuration, which I feel is more conventional way of presentation.   
 

 
The portion that in red, is the "extra" tone that is generated by the NFB12
I do not think any human is able to hear the difference between the 19K tone and the 23 K tone especially when it is play together. 
If you did you must have lots of ear training listening to sine waves. 
And since the 'extra' is outside the normal 20khz most standard test does not show it. 
 
It is hard enough to hear a tone at 19Khz. But you should be pick it up with any decent system. 
Since the 19K tone is in Udial, it is not surprising you heard something on most system. 
 
If you are using 48Khz the reflection is further up at about 30K since Nyquist frequency is push to 24K. 
(this is a guess as I have yet to test this out)
 
Attach is the waterfall diagram of udial with Pin22 connected to ground (0 volts) which is the setting as written on the datasheet of the 8741 
 

 
 
Next up I might try different setting for the capacitor mod as recommended by KingWa. He said NFB12 comes with 470pf and NFB11 comes with 100pf. 
 
Over the past few days/week I did learn a great deal about Amplifier, DAC design, apodizing filter. Not forgetting RMAA test and waterfall, The lesson alone is worth the price of the NFB12. 
 

 

[Audiophil]

Great, madwolf, thanks!
yes, these diagrams I'm familiar with.
And I agree 100% regarding the learning effect you mentioned.
Personally I raised the question to kingwa to go alternativly for the NFB-11 plus the DI (in order to avoid jitter which can harm the NFB-11).
We'll see...

 

[holland]

Quote:

Next up I might try different setting for the capacitor mod as recommended by KingWa. He said NFB12 comes with 470pf and NFB11 comes with 100pf.   
Over the past few days/week I did learn a great deal about Amplifier, DAC design, apodizing filter. Not forgetting RMAA test and waterfall, The lesson alone is worth the price of the NFB12. 
 

I honestly would not worry about the 470pF too much.  It was being used to say that the analog filter roll-off causes the warm sound, but the fact is the digital filter dominates.  If you put pin 4 of the WM8741 into brickwall mode (response 3 if I recall correctly) you will see the effect of the analog filter.  Based on the 192kHz sampling rate graphs, the effect is minimal. 
 
It would be nice, however, to know what the corner frequency is with the 470pF capacitor.

 

[Passingthrough]

I've had the NFB-12 for a while now (mine was in the first batch produced) and thought I'd post an update that I continue to be very happy with it.
 
I specifically wanted a DAC/amp with a smoother, lush sound and I feel that the NFB-12 delivers for me in that regard.  This was desirable for me for non-fatiguing listening, especially since some of my music collection may be of lesser quality.  I should mention that I also enjoy the Valab NOS DAC in our living room system, so I may enjoy a smooth sound signature more than some inclined to participate on this sort of forum would.  Anyway, I think that for real world listening, especially to music of mixed quality, the NFB-12 is excellent.  It offers a bit more resolution than the Valab NOS while still being forgiving and smooth and has many more features (head amp, pre-amp) for the exact same low price as the Valab.
 
Regarding amp use, I brought my M50's home from my office to use after reading Slaughter's comments on the pairing.  I agree that the M50 is really excellent with the NFB-12.  I'll be keeping them plugged into the NFB-12 from now on.  My HD580's sound a bit thin in comparision.  Side note: My personal opinion is that a direct comparison between M50 and HD580 using a wide variety of music will nearly always favor the M50's due to their wider frequency range (they provide significantly more bass).  Or maybe I'm just a basshead and never realized it.
 
Thanks to Kingwa for a really nice piece of gear at a great price.
 

 

[JaMo]

Thank You "passingthrough" for sharing.
 
It's good to hear that Your NFB-12 works as intended.. and that You're pleased with it over time. I look forward to get mine.
 
/Jan
 
 

 

[bhaishaki]

Hi Kingwa
 
Do you mean to say that even NFB-2 has similar high freq roll-off as NFB-12? Does it also use default 2X oversampling rate?
 
You have said the sound quality level is same as Sparrow or Fun. Since NFB -12 is designed with a different sound flavour, how different is the sound flavour different from Fun/Sparrow?
 
I'm asking this question because Sparrow-B and Fun-B are at the same price point(nearly) as NFB-12, it would be worth knowing the difference in sound quality/flavour other than the feature difference between them.
 
 
 
Quote:

In our NFB11 page we always post the different sonice between NFB11 and NFB12.
http://www.audio-gd.com/Pro/Headphoneamp/NFB11/NFB11EN.htm
 
English is not our mother tongue maybe we can't exact explain the sonic flavors.
 I think this link even though reviews the NFB2, but  the NFB12 sound flavor is quite near the NFB2 although sound quality is different level. Maybe can easier understand than our describing . They both are put the targets at smooth sounding and had a different to our ES9018 and PCM1704 based products.
http://www.digitalaudioreview.net.au/index.php/audio-reviews/digital-source-reviews/item/177-audio-gd-nfb-2-dac-19-series

 

[Jupe]

I thought I would follow Passingthrough's example and update my experience with the NFB-12. With so much speculation about such an (IMO) insignificant amount of noise/artifacts, I hope most of the readers and potential buyers aren't scared off thinking that the NFB-12 might be defected. Even I, a relative newcomer to the audiophile world, can hear and say this DAC/amp isn't neutral, but it performance is excellent, especially for the current asking price.
 
Most of my music would be considered electronica, alternative rock, and/or some form of dub/trance. Bands like Deadmau5, Ratatat, Muse, Gorillaz, Shpongle, and Ott. I'm listening to the NFB-12 with my M50's, and just like everyone else has said, they make a great pairing. Very energetic and encompassing, which is what I love for creating art.
 
The biggest trait people mentioned with first impressions was the boomy bass. It was a bit much to begin with, but I've found that it has been significantly tamed, tightened, and pushed back with time--though I feel high gain presents more punch by comparison. The soundstage has opened up a bit, letting me hear some of the faintest reverbs and other audio effects that I never noticed before, even in music I listen to daily. While the NFB-12 is pretty forgiving, I feel like I'm not getting the most out of its immersion and detail unless I'm listening to a lossless file. I'm sure that's universal, but it's worth mentioning for any other newcomers.
 
If it matters to anyone, I haven't found the NFB-12 to get very hot, unless I've been using it for a full day. Even at its hottest, it hasn't been uncomfortably hot, and hasn't affected my improv-sticky tack feet. Volume (I would say power, but I don't have any high-impedance phone to test) is impressive. For a while I didn't realize that the ASIO driver I'm using resets the Windows-controlled volume on occasion, but now that everything is back to where it should be I feel no need to turn the knob past 9o'clock on low gain, and even that's pushing it for me. On high gain, I can't go past 8o'clock for more than a minute or two. I noticed that mine has some channel distortion at extremely low volumes--it's barely audible on low gain, and on high gain it sounds as if the right channel is louder than the left, but switches depending on the exact knob placement (between 6 and 7). I don't know if this is regular or not, but I never have the knob turned all the way down, so it's never been an issue while listening to music.

 

[mtntrance]

Just wanted to chime in that I switched from the NFB-11 to NFB-12 primarily due to price point but I am also replacing a DAC19-DSP1 and C-2 with a NFB-1 WM and Phoenix to ultimately drive LCD-2s balanced.  What helped me decide on the Wolfson chip versus the Sabre was Kingwa telling me that the sound signature of the Wolfson was closer to the Reference series DACs and the DAC 19 that uses the 1704 chip.  I llike that sound signature.

 

[vinay]

How does the NFB-12 compare to FUN?
 
All this talk about high roll off , has got me confused..
I would actually prefer neutral sound, but since not all my music files are FLAC i decided to go for the NFB-12..  But after all this i am wondering if i should go for the NFB-11..
 
A n00b question- If i have music files of 128kbps bitrate is it wise to chose NFB-11?

 

[Carlsan]

 
Quote:

A n00b question- If i have music files of 128kbps bitrate is it wise to chose NFB-11?

 
Anything under 192 (except perhaps 192 variable) will not play well with a decent pair of headphones or for that matter, even coming out of a good quality mp3 player.
 
With  really top end headphones/amp, any mp3 will not sound that good at all, especially compared to a lossless format, such as flac.
 
To answer your question, depends a lot on the headphones you will be planning on using but any good amp, nfb-11 included,  will show low bitrate mp3's in a negative way.

 

[vinay]

Quote:

 
Quote:

A n00b question- If i have music files of 128kbps bitrate is it wise to chose NFB-11?

 
Anything under 192 (except perhaps 192 variable) will not play well with a decent pair of headphones or for that matter, even coming out of a good quality mp3 player.
 
With  really top end headphones/amp, any mp3 will not sound that good at all, especially compared to a lossless format, such as flac.
 
To answer your question, depends a lot on the headphones you will be planning on using but any good amp, nfb-11 included,  will show low bitrate mp3's in a negative way.

Currently i am using ATh-A700..

 

[BrianMendoza]

Quote:

Originally Posted by madwolf /img/forum/go_quote.gif
 
The 3 sound signature could be set by using different input data rate. 
Maybe using 44 is the "smooth musical" sound flavor
using 96 is in between "musical and neutral "
and 192 is "neutral "
 
 

 
Again, I'm new to DAC's so I was hoping someone could help me understand this a little bit more. When it comes to the NFB-12, how do you choose which input data rate to use?
 
Is it as simple as USB=44, Coax=96 and Opt=192?
 
If this sounds condescending at all, I am really not trying to be. I just really have no clue. and I'm a complete newb in the DAC world...
 

 

[tarnishedhalo]

 
Quote:

/img/forum/go_quote.gif  
A n00b question- If i have music files of 128kbps bitrate is it wise to chose NFB-11?

 
You might want to start upgrading from those 128 files and going for flac. I had to do it with my setup, carlsan is right I could hear a HUGE difference in sound quality, especially clarity of voices, instruments, and bass impact in low bit rate files compared to flac.

 

[dw1narso]

 
Quote:

A n00b question- If i have music files of 128kbps bitrate is it wise to chose NFB-11?

with a fixed bit rate, you need at least 256Kbps bitrate. Going up from there would not easily discernible, unless on some recording that highlight the difference quite strongly. Of course having 320Kbps MP3 or even FLAC or APE would be better and make it ready for future. But on general recordings, 256KVBR would be difficult to differentiate to 320K fixed bit rate already.
 
Personally, I'll choose 192Kbps (or even 128Kbps) MP3/OGG of excellently mastered records anytime VS FLACs of badly mastered records...
 
For example you will not get better sound of Celine Dion records by going from 128Kbps to FLAC. In fact, 128Kbps may make them more listenable... Pity her, such a great artist but badly produced records...
 
And at the other opposite example is go to www.mapleshaderecords.com, they share lots of their recordings on 128Kbps rate that you can download freely http://www.mapleshaderecords.com/main/freemp3s.php. And, be surprised to hear how good 128Kbps file can be.
 
 

 

[BrianMendoza]

Can anyone help me with my situation? (post 672)