• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Review and Measurements of Audio-gd NFB2 192 DAC

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,579
Likes
38,274
Location
Gold Coast, Queensland, Australia
ASR is about transparency.

Clearly (haha).

You get the official 'ASR piece of glass' award for the most transparent/cy mentions in one reply post. 8. Congratulations!

glass.jpg


No inscriptions, no badges or it wouldn't be 'transparent'...
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,368
Likes
234,381
Location
Seattle Area
@amirm you re not tolerant because you try to discredit all manufacturers that don't believe much in measurements.
Any engineer who doesn't measure to verify what he has built, doesn't deserve any business. Engineering is about precision. It is not about wishing some outcome and praying that it has occured by osmosis.

I am perfectly fine if they measure and publish the poor measurements and then say it sounds good. We exist here because they won't measure properly, or publish, sending out random gear into the marketplace, taking advantage of folks who don't know engineering (such as yourself).
 

The Mule

Member
Joined
Jan 23, 2019
Messages
29
Likes
20
what I don't get is why people get upset at the people who measured equipment that was subpar instead of at the manufacturers.

I own a Schiit Modi 2 U. I read the review of that unit here and now it's on sale**. I;m grateful at Amir for testing it and a bit upset at the whole audio community (read Head Fi) for recommending it under dubious circumstances, as well as at Schiit for producing subpar stuff and in certain cases not putting attention to safety.

** I now have a D10 BTW and I believe there's a large difference. The thing is, I wasn't using Modi 2 U through SPDIF where the differences might not be perceptible against a D10, but I was using it through USB, the worst possible input to use the Modi with.

I have been trying to figure out where to put the following, it could go in its review thread, but this post echoes my thoughts/experience too.

I have a Woo Audio WA7, Fireflies. I've like how it looks, and I've liked how it sounded, until Amir reviewed it. :oops: I have a few different sets of USB DACs and headphone amps that I cycle through at work, and now, I can't seem to want to listen to this one again.

No, I've never really pushed it, but now I know it doesn't measure that well, but it also doesn't have the even order harmonic tube magic really that I bought it for. (I do have a 1st gen model, but I actually never used its internal DAC.)

So sure, someone could say, well how can its sound change when all that changed is that I know how it measures? And you'd be right. It doesn't make a lot of sense. But I can also say, ignorance can be bliss too. So now I joke with myself that I just got a Valhalla 2, because I liked how the 1st one I have sounds, and how the newer rev at least theoretically improves on it. So while I hope that someday it gets reviewed here, maybe I'm also hoping it doesn't. ;)

If I may be so bold, I think that Amir wouldn't kind finding that "tube magic" too, but he doesn't seem to have yet. It is still possible that there's a poorly measuring tube amp out there somewhere, with predominantly even order harmonics as its main distortion component, that possibly does help to color the sound in an appealing way to some people. (Note how I carefully constructed that sentence! :D)

[ I also have a Soekris 1321 DAC, and there's no magic there either. Actually, I just got a Massdrop Grace SDAC, and I'm liking the SDAC a lot more simply because it loses signal lock a tenth as much as the Soekris does!]
 

Calexico

Senior Member
Joined
May 21, 2019
Messages
358
Likes
72
@amirm good evening sir.
Did you sell your mark levinson dac ? Was it a multibit one?
Are cheap good measuring dacs satisfaying you as much?
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,368
Likes
234,381
Location
Seattle Area

LTig

Master Contributor
Forum Donor
Joined
Feb 27, 2019
Messages
5,760
Likes
9,442
Location
Europe
[..]
I have a Woo Audio WA7, Fireflies. I've like how it looks, and I've liked how it sounded, until Amir reviewed it. :oops: I have a few different sets of USB DACs and headphone amps that I cycle through at work, and now, I can't seem to want to listen to this one again.

No, I've never really pushed it, but now I know it doesn't measure that well, but it also doesn't have the even order harmonic tube magic really that I bought it for. (I do have a 1st gen model, but I actually never used its internal DAC.)

So sure, someone could say, well how can its sound change when all that changed is that I know how it measures? And you'd be right. It doesn't make a lot of sense.
Oh, it makes sense knowing how fallable the human hearing sense works. The sound has not changed but your mind has. This is the same mechanism which let audiophiles buy expensive and beautiful looking equipment because "if it looks so good it must sound better". And then it does - in their mind.
 

UFO

New Member
Joined
Jun 22, 2019
Messages
1
Likes
1
Wait a Second... If this stands for No Feedback design, then this DAC is freaking good! How many of the ones that use feedback would actually measure completely worse than this if they were not using full levels of feedback on OP amps and so? Actually, this would mean it's incredibly well executed, and if it used minimal feedback would clean all the noise you can measure and voila. The point here is ... how good it does sound considering that the 96 dB of a Redbook is not affected while they are on circuitry with no feedback at all.

And that is a great thing. I mean, there are several Amplifiers that measure 0.0005% and sound like crap, whilst there are some that are 0.08 and sound divine. So...

These reviews are quite unclear. If Kingwa (he's the designer for what I understand?) is getting certain results and voicing their DACs in a way he's actually meant to make a statement as to designing a good circuit from the get-go, without using tools (such as Feedback) to make it work regardless how poor was at the beginning, then this is remarkable. Why wouldn't he add slight feedback after he has achieved such nice measurements without it to clear it even further? That I do not know.

I will need to hear now an Audio GD Dac, because I am intrigued.
 

SIY

Grand Contributor
Technical Expert
Joined
Apr 6, 2018
Messages
10,383
Likes
24,749
Location
Alfred, NY
Voicing a DAC? Whaaaaaat?

You might read up on how feedback works, since you are under some misunderstandings (the Bruno Putzys paper is linked extensively around the forum and can be quite enlightning). As well, I have yet to see a so-called "no feedback" circuit that doesn't have feedback.

I mean, there are several Amplifiers that measure 0.0005% and sound like crap...

Can you be specific here?
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,521
Likes
37,050
Wait a Second... If this stands for No Feedback design, then this DAC is freaking good! How many of the ones that use feedback would actually measure completely worse than this if they were not using full levels of feedback on OP amps and so? Actually, this would mean it's incredibly well executed, and if it used minimal feedback would clean all the noise you can measure and voila. The point here is ... how good it does sound considering that the 96 dB of a Redbook is not affected while they are on circuitry with no feedback at all.

And that is a great thing. I mean, there are several Amplifiers that measure 0.0005% and sound like crap, whilst there are some that are 0.08 and sound divine. So...

These reviews are quite unclear. If Kingwa (he's the designer for what I understand?) is getting certain results and voicing their DACs in a way he's actually meant to make a statement as to designing a good circuit from the get-go, without using tools (such as Feedback) to make it work regardless how poor was at the beginning, then this is remarkable. Why wouldn't he add slight feedback after he has achieved such nice measurements without it to clear it even further? That I do not know.

I will need to hear now an Audio GD Dac, because I am intrigued.
No loop global feedback is usually what is meant. It isn't the only kind of feedback, and as mentioned by SIY, you'll be hard pressed to find a good functioning circuit that has no feedback involved. The paper by Putzeys:

https://linearaudio.net/sites/linearaudio.net/files/volume1bp.pdf

The F-word or, why there is no such thing as too much feedback.

Or same article different place. EDN.
https://www.edn.com/design/consumer...fiers--Why-there-is-no-such-thing-as-too-much
 

Calexico

Senior Member
Joined
May 21, 2019
Messages
358
Likes
72
Hello
One has the right to believe that minimizing feedbacks has advantage that may be not shown.
I think the most obvious advantage of opamp is their cost and good measurements what's why lot of lasy manufacturers don't go further on the output stages.

When you see number of components in audio gd and the price and you compare with the price of toppings dx7s for exemple you see that topping should be much more cheaper.
Topping dx7s just four cheap op amp tpa1612 and 2 cheap headphone amps tpa6120
No research for design.
Audio gd nfb 11.38
Lot of components proprietary designs.

Then what does justify the high price of dx7s?

I think the question is more
Do you know a good design that has very few feedback?
Or will asr always won't recommend such designs?
Do you know good designs that are differents from the classic delta sigma +opa ?

Why always promoting lazy manufacturers that just do the easiest designs?
Don't forget they They do it for cost no for audio.
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,521
Likes
37,050
Hello
One has the right to believe that minimizing feedbacks has advantage that may be not shown.
I think the most obvious advantage of opamp is their cost and good measurements what's why lot of lasy manufacturers don't go further on the output stages.

When you see number of components in audio gd and the price and you compare with the price of toppings dx7s for exemple you see that topping should be much more cheaper.
Topping dx7s just four cheap op amp tpa1612 and 2 cheap headphone amps tpa6120
No research for design.
Audio gd nfb 11.38
Lot of components proprietary designs.

Then what does justify the high price of dx7s?

I think the question is more
Do you know a good design that has very few feedback?
Or will asr always won't recommend such designs?
Do you know good designs that are differents from the classic delta sigma +opa ?

Why always promoting lazy manufacturers that just do the easiest designs?
Don't forget they They do it for cost no for audio.
Do you know a good design with little feedback? If not, then why the faith in it. One has the right to believe anything I suppose. Doesn't mean it makes any sense. Belief no feedback has benefits that can't be shown seems odd.

ASR would recommend any design that produces excellent results. Excellence isn't found in faith of voodoo methods. Excellence is found in something that reproduces the input signal with high fidelity.
 

Calexico

Senior Member
Joined
May 21, 2019
Messages
358
Likes
72
believing that science can be improved is believing in voodoo???
Well how do you call believing that everything that is felt and not yet demonstrated is always wrong??
 

pozz

Слава Україні
Forum Donor
Editor
Joined
May 21, 2019
Messages
4,036
Likes
6,825
The cable guys should jump on that to justify their burn-in times.

After all, you have to get the old factory electrons out of the cable and get new, active electrons in, before cables reach their maximum potential in your system. :)
Not quite in this vein, Cardas' claim to fame with their cables is that they can control the speed of electricity such that propagation in the conductor and the dielectric match.

Weirdly, the Cardas Clear interconnects I've tried distinctly attenuate the signal starting at the upper end of the midrange. Would be nice to see them measured, eventually.
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Did we go through the evils of feedback, jump to the benefits of meditation for use as a tool for audio testing, and now we're back at the sins of feedback? I’m going to apply my nihilistic approach for this one...
Maybe we shoud start selling NNFB designs, which cancel out the non-feedback! I'm sure they'll sound better :D!!
:thinking: emoji
 
Top Bottom