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Audio-gd NFB-9 DAC with volume control

post #1 of 23
Thread Starter 

Another new goodie, looks like a NFB8 with volume control and digital filters.

http://audio-gd.com/Pro/dac/NFB9/NFB9EN.htm


Edited by tim3320070 - 8/27/11 at 3:23pm
post #2 of 23

Cool!

post #3 of 23

Guys,

 

other comments than just "cool"?

I´ve been looking for exactly a machine like that since I´m really impressed with the FUN from Kingwa.

The NFB 9 really looks quite sophisticated

Will I be the first one to buy it?

 

Cheers

Kai

post #4 of 23
Thread Starter 

Read up on the NFB-8, it's the same essentially.

post #5 of 23

Bumping this thread since the NFB-8 seems to be discontinued (at least from looking at audio-gd's English website).

 

Does anyone have any impressions of the NFB-9?  Better yet, any comparisons to the AURALiC ARK MX+?  I've been getting more interested in the gear coming out of China, after recently acquiring a great piece Chinese preamp, and hearing that the quality of some premium Chinese gear has now reached a remarkable price-performance mark.

post #6 of 23

Which digital filter has the most natural sound ?  

post #7 of 23

NFB-8.1 is similar to NFB-9, it also has 9 digital filters.  

post #8 of 23

Does anybody else own the NFB9?  I just received mine today, and am not happy.

 

The problems are numerous.

 

(1) No documentation with the unit.  Once I realized that the web site description provides details on the INPUT1-5 assignments at least I now knew which input  was "optical".  And the eight graphs of the eight filters... well, how do I know which one is "flat"?  I decided to just go with filter 1 since that seems the least "crazy", so maybe it's what I want.

 

(2) The remote does not seem to have a battery compartment, although it works right out of the box.  So there must be a battery in there from China.  I removed the four screws holding the back plate secure but the plate would not come out (or maybe I need to work on it more).  So if/when the battery every needs replacing I'm stumped!

 

(3) I connected both XLR and RCA output cables to my Stax SRM-007tII headphone amp, because whereas the XLR cables go directly from DAC to amp my RCA path goes through a DBX EQ (as I have gotten used to 14/10 tone control when listening to movies and HDTV).  So I wanted to be able to compare the tone-controlled RCA output path vs. the flat XLR output path, just to see the difference.

 

Well it's very difficult to do a fair comparison, because the RCA output level is so low that it almost seems like something's wrong.  I tried turning up the volume... and it maxed out at 48 but the level is still unacceptably low.  Definitely not right, and I could not possibly keep this $1400 units with this output volume level problem on RCA.

 

(4) The unit has four "legs" which are what look like chromed screw-in things that look like they have a threaded hole in the middle, perhaps to screw in cones or rubber feet or something.  Don't know.  Except that there were no rubber feet included, so this unit simply sits on these four metal feet.

 

Well, it's crooked!!!  On my shelf it's actually sitting on three of the four metal legs, with the fourth one "up in the air" a little.  So when I grab onto the case to hold it when inserting cables on the back connectors, the silly unit rocks back and forth on the two legs which are making contact with my shelf!!!   It does not sit flat on all four feet!  RIDICULOUS!!!

 

 

All in all I'm extremely disappointed.  I do not want to keep the unit, and hope they will accept it back.  I'll have to pay shipping I guess, but it is simply unacceptable.

 

I had bought this unit having never heard it, based strictly on people's comments, reviews, etc., which rate it very highly.  I'm afraid I will not be one of the people giving it a positive review.

 

 

Does anybody else actually own one?  Do you have an RCA level problem?

post #9 of 23

As I replied in the email, the RCA outputs are connect from the XLR hot signal.

So  the RCA output level should be exact same as the level of the XLR hot signal .

post #10 of 23
I have both the Ref 7.1 dac and the Master-6 pre/hp amp from Audio-gd.
The RCA signal should be 6dB's higher than the XLR output. If it's not through your headphones, then there might be something else making that difference - for instance the extra headroom your equalizer has to keep from clipping when you boost parts of the audio band.

The case of my Master-6 arrived in absolutely perfect state twelve days ago. My Ref 7.1 dac arrived in May or June, and the top had obviously gotten a pressureduring transportation, since it was curving slightly down, however not visible from the front. In addition one of the RCA plugs also got hit - bending slightly sidewards. If your entire case is skewed then that is a major issue, but did you check if it's the shelf that's uneven also?

I didn't get any documentation for my units either except for what's on the web site. I agree, that it would be usefully to have more useful info about how these filters work and most importantly do to the sound, and also a description with pictures of how to do the changes in the unit.

The legs are made of solid aluminum as I understand it, and are supposed to be as they are. I think it's like a broad cone that let's the unit sit directly on a table without protection.

I look at Audio-gd as a budget high end / hifi brand (depending on the unit) in the good sense: they are not charging you a considerable amount of money for the casing and finsh, but in terms of sound quality, audio components etc. you get a better product for the money.
Edited by LarsHP - 12/31/11 at 1:58am
post #11 of 23
Quote:
Originally Posted by Kingwa View Post

As I replied in the email, the RCA outputs are connect from the XLR hot signal.

So  the RCA output level should be exact same as the level of the XLR hot signal .


I'm not sure I understand.

 

In your email you said that RCA is 1/2 the output level of XLR.  Although I do want to use XLR as well, mainly I need to use the RCA path and 1/2 the XLR level is unacceptable.

 

Is there anything that can be done to change this?

 

 

Also, what are all those little black jumpers in the plastic bag with the optical cable?  Are they to be used for something?  Are they for me?

post #12 of 23
Quote:
Originally Posted by LarsHP View Post

I have both the Ref 7.1 dac and the Master-6 pre/hp amp from Audio-gd.
The RCA signal should be 6dB's higher than the XLR output. If it's not through your headphones, then there might be something else making that difference - for instance the extra headroom your equalizer has to keep from clipping when you boost parts of the audio band.

 

I will re-wire things, to bypass the EQ and go straight from RCA output of NFB9 to the RCA input of the Stax amp.  But I was using the EQ in "flat" mode, with no gain anywhere.  I run other devices RCA through the EQ and have never had this problem until now, with the NFB9's RCA outputs.

 

If the RCA signal from the NFB9 were 6db higher than the XLR output I wouldn't be posting here.  I'd love to have that situation instead of what appears to be the reverse.  I even disconnected the XLR cables, thinking maybe having both RCA and XLR connected at the same time might have been causing an issue... either for the NFB9 or for the Stax amp (seemed unlikely since the Stax amp supports two RCA inputs and one XLR input).  No difference.  It's obviously an issue in the RCA path itself.

 

As far as the fourth aluminum leg being "higher" than the other three (so that the unit "rocks" on a flat surface if you touch it on that fourth corner), I'll examine the underside of the unit to see if there's any physical damage.  But I don't think that could have happened.  It arrived securely packed in styrofoam blocks.  It's like the fourth aluminum leg got screwed in "too far", so that it's just higher up than the other three.

post #13 of 23
Quote:
Originally Posted by dsperber View Post



I'm not sure I understand.

In your email you said that RCA is 1/2 the output level of XLR.  Although I do want to use XLR as well, mainly I need to use the RCA path and 1/2 the XLR level is unacceptable.

Is there anything that can be done to change this?


Also, what are all those little black jumpers in the plastic bag with the optical cable?  Are they to be used for something?  Are they for me?

I can see you don't understand. The point is, that there is no RCA path, if I understand this correctly.
The RCA output is in fact the XLR output, but without the inverted path. That's how most if not all balanced design audio circuits are made. In other words: if the XLR signal sounds fine, then the RCA / single ended output should be is also. As you can see from this, there is nothing you can do to change this since this is how balanced audio circuits are made. You can see it in the specifications: XLR out is double as much as RCA out.
Edited by LarsHP - 12/31/11 at 3:12am
post #14 of 23

RCA being 1/2 of the XLR volume is completely normal, that´s the way it always is (and should be). The usual RCA out standard is 2.5V and XLR being a balanced connection (+, - and ground) has that on both pins, in other words 5V. What you can, however, do is ask Kingwa which volume setting in XLR preamp mode is the same as RCA in full output mode. That way you can compare the two.

post #15 of 23

Ok.  I'm settling down and getting used to LOTS of new equipment, and new sound.  My SRM-007tII is new, my Audioquest King Cobra XLR cables are new, my NFB9 is new, and using the optical output from my Smyth Realiser (instead of the analog headphone output) is new.  I think that all of this was probably 1/2 of the issue, that I was obviously very used to how my system sounded before and there's lots changed here (for the better) so I just have to give my brain a little time to adjust to the considerable difference in loudness and tone.

 

Also, given that it apparently true that RCA levels are 1/2 XLR levels and that's normal, I've figured out a way to compensate for this using my DBX EQ.

 

So with six remotes spread out in front of me, all three inputs to the Stax SRM-007tII in use, bouncing back and forth between the three inputs and adjusting things accordingly, and a few hours of fine-tuning effort expended, I've managed to come up with what seems like a perfectly acceptable solution involving all of my components:

 

(a) Smyth Realiser A8 fed from discrete multi-channel analog preamp-out of Yamaha AVR (switcher for all A/V source components)

 

(b) optical output of Smyth Realiser A8 feeds optical input of NFB9

 

(c) XLR output of NFB9 goes to XLR input of SRM-007tII (INPUT3)

 

(d) RCA output of NFB9 goes to RCA input of DBX 14/10 EQ; RCA output of DBX EQ goes to RCA input of SRM-007tII (INPUT2)

 

(e) RCA "headphone output" of Smyth Realiser A8 goes to RCA input of SRM-007tII (INPUT1)

 

The key new ingredient in the story is that I've now used my DBX 14/10 EQ to create a new preset (for the RCA path from the NFB9), to increase the level on the RCA-output path from the NFB9 to equal that of the XLR path.  I also "shaped" the EQ so that it sounds tonally just like XLR path.  In fact, they now sound essentially identical.  Of course having done this, I now can't seem to explain to myself or justify why I would then even want to use the RCA outputs if I'm just trying to duplicate the level and tone of the XLR output anyway!  Why not just use the XLR path in the first place??

 

I've also adjusted the volume on the NFB9 (to 44), and the volume on the Realiser (to -9), so that switching the SRM-007tII between INPUT1, INPUT2 and INPUT3 all three sound equally loud.  Of the three inputs, only INPUT2 (going through the DBX EQ) has been tonally adjusted, but because of how I adjusted the EQ preset INPUT2 also sounds tonally like INPUT3.  And, remarkably, even though INPUT1 is the "raw" headphone output from the Realiser (i.e. via the built-in internal DAC in the Realiser) and no longer goes through the DBX EQ as it used to, it now sounds tonally and loudness identical to INPUT2 and INPUT3.

 

Obviously the explanation for this last observation is that I adjusted the DBX EQ preset for INPUT2 (RCA out of NFB9) to match the loudness and tone of INPUT3 (XLR out of NFB9), which is thus really an unaltered "flat" XLR/RCA duplication via the NFB9 external DAC for what the Realiser itself is putting out "flat" on its headphone outputs through its own internal DAC which goes directly to INPUT1 (no longer tone adjusted by the EQ).  The use of the DBX EQ for INPUT2 simply compensates for the low-level RCA path out of the NFB9, and also adjusts the tone on that path to match the excellent tonal quality of the XLR path (INPUT3).

 

Bottom line: I now have INPUT1, INPUT2 an INPUT3 all sounding identical (loudness and tone).

 

And... it sounds astonishingly good.  I've decided that I certainly seem to enjoy the tonal characteristics of the XLR sound on INPUT3, which is "flat" and not tonally adjusted at all, and effectively a duplicate of the Realiser's headphone output (on INPUT1).  Of course since I've adjusted things so that INPUT2 sounds the same as INPUT3, again I am now arguing with myself as to why I would ever use that RCA path on INPUT2, except maybe if for some reason I actually do desire some other somewhat adjusted EQ settings for different tone control.

 

I've now listened to DD5.1 HDTV programs as well as to 2-channel stereo CD audio, and I have fast become very much impressed with the XLR sound... and also its duplicate RCA sound (adjusted via DBX EQ).  And it turns out the built-in DAC in the Realiser does not seem to produce any noticeable degradation in sound quality from that of the NFB9.  I'm sure that will not always be how it sounds, but for the things I've listened to tonight there doesn't seem to be a "night and day" difference.

 

I still have yet to sample 5.1 and 7.1 BluRay movies, but I suspect I will again marvel at how the XLR "flat" sound is very appealing, and sounds considerably better than what I've been listening to for years now, i.e. that old DBX EQ preset which is now no longer in use.  Of course it could be the NFB9 itself which is responsible for that very appealing XLR "flat" sound I'm quickly growing very fond of.

 

Nevertheless, the whole new sound (i.e. XLR) from the new setup is actually quite stunning.  And when I go back to the old DBX EQ preset I used to listen through I'm amazed at how much I was missing.

 

So all in all, a very exciting first day with the new NFB9.  Learned a lot, and made some radical changes in my setup.

 

 

P.S. - I'm still bothered by the "rocking" of the unit caused by that fourth leg mismatch.  And I still don't know what all those black jumpers are provided for.  Oh well.  It now sounds GREAT!  And that's what I really paid for.


Edited by dsperber - 12/31/11 at 5:11am
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