• 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

DWPress

Addicted to Fun and Learning
Forum Donor
Joined
May 30, 2018
Messages
966
Likes
1,398
Location
MI
Hadn't checked in here for awhile but knew immediately that a broken pink panther meant for another poor AudioGD device. Glad to see I wasn't let down.;)
 

Tup3x

Active Member
Joined
Nov 17, 2018
Messages
162
Likes
130
Location
Finland
Colorless dacs are like sterilized milk cheese.
No bacteria and boring.
There's plenty of ways to ruin (or colour) the sound. The thing is, most don't want the device to do it because there's no way to fix it. Impossible to get clean sound.
 

THW

Senior Member
Forum Donor
Joined
Nov 21, 2018
Messages
412
Likes
630
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...

*eternal recurrence intensifies*
 

maxxevv

Major Contributor
Joined
Apr 12, 2018
Messages
1,872
Likes
1,964
Hadn't checked in here for awhile but knew immediately that a broken pink panther meant for another poor AudioGD device. Glad to see I wasn't let down.;)

The results blew Pinky's mind (head) ... and probably legions of Audio-GD fans' too.
 

THW

Senior Member
Forum Donor
Joined
Nov 21, 2018
Messages
412
Likes
630
The results blew Pinky's mind (head) ... and probably legions of Audio-GD fans' too.

Would they though?

Aren’t Audio-GD’s fans all proponents of just “using your ears and hearing”?
 

sweetsounds

Active Member
Joined
Apr 24, 2019
Messages
140
Likes
278
I doubt, that you can hear the "weaknesses" of this DAC when listening to music. Do you really believe, that you can dezecz a 2nd harmonic at -60dB? I probably can't. I believe, this is maybe not state of the art, but it's good enough. All the China DACs here measure well enough.
So I don't see a reason to blow the head off a poor Pink Panther.


However, there are things my scientific head won't understand:
I happily listened many years to my SqueezeBox touch's DAC into a nicely measuring Chinese integrated amp.
I got a good deal on a used Benchmark DAC (https://www.stereophile.com/content/benchmark-dac1-usb-da-processor-headphone-amplifier-measurements). Good measurements. It sounded more present, so I kept it for 3 years.

Things changed a lot when I upgraded my amp to a Classé CP-800 II pre-amp in 2014 after my Chinese amp blew. What a revelation in details when using its internal DAC, music and stage sound so great and detailed. Benchmark is sounding very direct forward, Classé paints an image. Yet, I can't correlate it to any measurements. (https://www.stereophile.com/content/class233-cp-800-da-preamplifier). Maybe Classé measures slightly better, so this is the reason.

This year I stumbled across Amir's great reviews and was amazed to see the progress in DAC design. Out of curiosity I ordered the SMSL SU-8 in March as it was only a small invest. There is little difference to the Classé, maybe even more details, a little cleaner sounding. So I kept it with a big smile. Can't believe that a 200$ unit beats a 4000$ unit. Amazing!

A dealer stops by to show me his Lampizator Big Seven ($12,000), a tube-based DAC. Well, it also sounds good, probably measures like a nightmare. Details are lost, stage is shallower. SMSL wins easily! Dealer rolls in $1000 tubes, $700 cable, no improvement.
Wow, SMSL beats $12,000. So: Measurements do work!

Since the Topping D70 even measures better, I now plan to order it. It should even be better!

Now this week, the guy doesn't want to give up and stops by with a used 2014ish Metronome C8 DAC (was $16,000) based on AKM with Philips tubes. I don't know how it measures (probably bad), but it sounds sooo full and warm with great stage and detail. I kept it for 5 days and haven't enjoyed my music like this for a long time (I was able to switch back and forth with Classe/SMSL).
I had to return it yesterday (anyway price is out of range) and sound went back to well performing SMSL, but also to less emotion.

Now please advise. All placebo? Believe measurements? Believe the impression?
 

Frank Dernie

Master Contributor
Forum Donor
Joined
Mar 24, 2016
Messages
6,445
Likes
15,781
Location
Oxfordshire
I doubt, that you can hear the "weaknesses" of this DAC when listening to music. Do you really believe, that you can dezecz a 2nd harmonic at -60dB? I probably can't. I believe, this is maybe not state of the art, but it's good enough. All the China DACs here measure well enough.
So I don't see a reason to blow the head off a poor Pink Panther.


However, there are things my scientific head won't understand:
I happily listened many years to my SqueezeBox touch's DAC into a nicely measuring Chinese integrated amp.
I got a good deal on a used Benchmark DAC (https://www.stereophile.com/content/benchmark-dac1-usb-da-processor-headphone-amplifier-measurements). Good measurements. It sounded more present, so I kept it for 3 years.

Things changed a lot when I upgraded my amp to a Classé CP-800 II pre-amp in 2014 after my Chinese amp blew. What a revelation in details when using its internal DAC, music and stage sound so great and detailed. Benchmark is sounding very direct forward, Classé paints an image. Yet, I can't correlate it to any measurements. (https://www.stereophile.com/content/class233-cp-800-da-preamplifier). Maybe Classé measures slightly better, so this is the reason.

This year I stumbled across Amir's great reviews and was amazed to see the progress in DAC design. Out of curiosity I ordered the SMSL SU-8 in March as it was only a small invest. There is little difference to the Classé, maybe even more details, a little cleaner sounding. So I kept it with a big smile. Can't believe that a 200$ unit beats a 4000$ unit. Amazing!

A dealer stops by to show me his Lampizator Big Seven ($12,000), a tube-based DAC. Well, it also sounds good, probably measures like a nightmare. Details are lost, stage is shallower. SMSL wins easily! Dealer rolls in $1000 tubes, $700 cable, no improvement.
Wow, SMSL beats $12,000. So: Measurements do work!

Since the Topping D70 even measures better, I now plan to order it. It should even be better!

Now this week, the guy doesn't want to give up and stops by with a used 2014ish Metronome C8 DAC (was $16,000) based on AKM with Philips tubes. I don't know how it measures (probably bad), but it sounds sooo full and warm with great stage and detail. I kept it for 5 days and haven't enjoyed my music like this for a long time (I was able to switch back and forth with Classe/SMSL).
I had to return it yesterday (anyway price is out of range) and sound went back to well performing SMSL, but also to less emotion.

Now please advise. All placebo? Believe measurements? Believe the impression?
On the reviews I have seen of Metronome DACs (on Hi-Fi news) the thing that stands out is they have very, very high jitter 1200 psec on one, which is a couple of orders of magnitude worse that SOTA.
 

Cbdb2

Major Contributor
Joined
Sep 8, 2019
Messages
1,530
Likes
1,486
Location
Vancouver
Negative feedback re-injects a sample of the amplifier’s output signal back into the input, 180 degrees out of phase, in an attempt to reduce amplifier non-linearity and distortion. In practice, negative feedback tends to slow the amplifier down and sucks the emotion and life out of the music. High feedback designs usually sound sterile, boring and lifeless, while low or zero feedback designs provide for a more immediate and natural sound.

You need to learn how feedback works. You spout audio myth with no back up ( the Essex echo paper is full of holes and rebuffed often). How does it " slow down" anything (measure it), it may reduce the bandwidth, but audio doesnt need a 200khz bandwidth. And you like others find a clean non distorting amp sterile. So get an effects box, thats what your looking for.
 

Sal1950

Grand Contributor
The Chicago Crusher
Forum Donor
Joined
Mar 1, 2016
Messages
14,074
Likes
16,609
Location
Central Fl
Now this week, the guy doesn't want to give up and stops by with a used 2014ish Metronome C8 DAC (was $16,000) based on AKM with Philips tubes. I don't know how it measures (probably bad), but it sounds sooo full and warm with great stage and detail. I kept it for 5 days and haven't enjoyed my music like this for a long time (I was able to switch back and forth with Classe/SMSL).
I had to return it yesterday (anyway price is out of range) and sound went back to well performing SMSL, but also to less emotion.

Now please advise. All placebo? Believe measurements? Believe the impression?
Tube or SS output stage?
Read the measured problems reported with the tube stage by HiFiNews
https://www.absolutesounds.com/pdf/main/press/Metronome C8+ HFN 09-15 4web.pdf
 

tktran303

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
683
Likes
1,181
Now this week, the guy doesn't want to give up ...

This is part of the problem. Human's need for change, for the sake of change. Or for new experiences. Upgrade-itis. Whatever one wants to call it.

Until one can learn to properly conduct controlled listening tests, one's perceptions or opinions will lead you one to constantly chase one's own tail, and form incorrect analysis/interpretation.
 

tktran303

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
683
Likes
1,181
I doubt, that you can hear the "weaknesses" of this DAC when listening to music. Do you really believe, that you can dezecz a 2nd harmonic at -60dB?

You you can. But you won't hear it a "grossly bad distortion"

In audio signals, Non-linear distortions are exactly what imparts the "characteristics" of a sound or a tone. This is what allows middle C of a piano to sound different to the same C of guitar or a violin. All three would have the same fundamental of 262Hz, different amounts of overtones (harmonics ), that allow it to give its character.

Class leading electrodynamic drive (loudspeaker or headphone) units will have a THD of around 0.1%, which is -60dB down.
Even when these drivers have been EQ'ed to have a perfectly flat frequency responses, each will have its own individual tonal characteristics. Subtle, but enough to distinguish.

I think we do a disservice when we way that this that product "measures badly", hence it "sounds bad", or make fun or mock people who have had it in their system and seem to enjoy the music despite of it. Asking ourselves "how can they possibly enjoy such distorted music?"
Well it’s not like a painting- that has been folded or trampled on or torn or ripped, or put through a photocopier or fax.
Making analogies like this will further alienate ourselves from other music lovers. We are all trying to learn and understand the science of signal creation & storage ( creation of music ) and retrieval ( playback of music).

Trained listeners will be able to tell that this DAC cannot reproduce even the simplest audio signals to the highest level of fidelity presently available. They will warn others to avoid making a purchase, and these warnings will become more intense if the product price is relatively high.

But the truth is probably a bit more boring or benign. But each side of the camp will make their most ardent arguments ("climate change is fake news and doesn’t exist" vs. the "by 2050 Earth is going to become a ball of fire " both are patently false but gets people's attention)

It's probably a bit closer to an studio effects unit- it creates artifacts that weren't in the original signal, but may end up being perceptually preferable (pleasing), as having details or depth.

Traditional equipment reviewers (who are seldom required to disclose affiliations or conflicts of interest) use sophistry to make excuses for the product. The type of products that audition with comments like "requires careful system matching"

What that really means is- hey look there are clearly some shortcomings with this device, But if you add this little bit of distortion type A into system we it it's a little bit of distortion type B there, mix it around with of your own room acoustic problems, ("experiment with toe-in, "adjust speaker to wall distance"), and transducer idiosyncrasies ("try different earpads", "adjust for fit and position on head") and unpredictable listening preferences... well... you may just like it!!!

And if you don't not, well you're going to have fun anyway (you're the cat), because it's all about the "journey to audio nirvana" - looking for that right mix of "audours" to tickle your cranial nerve VIII to eargasm.

Another approach, one assuredly more rational, may follow something along the lines of:
"All available evidence suggests that this DAC is audibly transparent (or not), hence i will keep it (or move on)"
 
Last edited:

milosz

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
584
Likes
1,643
Location
Chicago
There has been a movement in Hi-Fi to select certain components, or pairings of components, to yield a specific sound character that the listener finds enjoyable and may have the opinion that the resulting sound is "more musical."

There used to be features built in to preamps, integrated amplifiers and receivers that were intended to do this sort of thing- they were called "tone controls."

In the quest by engineers for low coloration they were largely abandoned, but audio hobbyists have brought them back in the form of speaker cables with L/C/R filters in them, high distortion S.E.T. amplifiers, zero-feedback circuits and other anachronisms and oddities. Marketing departments have tried to sell the badly flawed notion that somehow these things are "right" when all well engineered and tested designs are somehow "wrong."

Now, there is nothing wrong with enjoying the serendipitous euphony of a certain pair of speakers paired with a tube amp that has fairly high output source impedance and therefore imposes a frequency response characteristic on the the overall sound that just happens to sound pleasing to a given listener. But one needs to understand the science here- this is a COLORATION - and does not mean that somehow this system is "right" while the same speakers on a solid state amp with very low output source impedance is "wrong." Frequency response variations created by tube amplifiers driving real-world loads are not some kind of "proof" of the superiority of tubes over transistors, which some seem to claim.

If you like your gear to introduce certain kinds of distortion, by all means - distort away. Just be aware that you are adding things to the sound that are not in the recording.
 

LTig

Master Contributor
Forum Donor
Joined
Feb 27, 2019
Messages
5,760
Likes
9,442
Location
Europe
Now this week, the guy doesn't want to give up and stops by with a used 2014ish Metronome C8 DAC (was $16,000) based on AKM with Philips tubes. I don't know how it measures (probably bad), but it sounds sooo full and warm with great stage and detail. I kept it for 5 days and haven't enjoyed my music like this for a long time (I was able to switch back and forth with Classe/SMSL).
I had to return it yesterday (anyway price is out of range) and sound went back to well performing SMSL, but also to less emotion.

Now please advise. All placebo? Believe measurements? Believe the impression?
I believe the impression. Non flat frequency response may be the answer.
 

milosz

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
584
Likes
1,643
Location
Chicago
I believe the impression. Non flat frequency response may be the answer.

Nelson Pass has found that adding a little 2nd order harmonic distortion to the sound in negative phase relation to the fundamental results in giving listeners the impression that there is greater depth to the stereo image and a "richer" sound. Doing the same thing in positive phase gives many listeners the experience of a "close up, forward" sound with enhanced detail. I suspect that the tube analog stages of this fancy DAC were adding some low-order harmonic distortion. If you want the same effect from your SMSL, you can build Nelson Pass DIY H2 contraption for under $50 to add some low order distortion. See https://positive-feedback.com/audio-discourse/the-pass-h2-harmonic-generator/
 

LTig

Master Contributor
Forum Donor
Joined
Feb 27, 2019
Messages
5,760
Likes
9,442
Location
Europe
Nelson Pass has found that adding a little 2nd order harmonic distortion to the sound in negative phase relation to the fundamental results in giving listeners the impression that there is greater depth to the stereo image and a "richer" sound. Doing the same thing in positive phase gives many listeners the experience of a "close up, forward" sound with enhanced detail. I suspect that the tube analog stages of this fancy DAC were adding some low-order harmonic distortion. If you want the same effect from your SMSL, you can build Nelson Pass DIY H2 contraption for under $50 to add some low order distortion. See https://positive-feedback.com/audio-discourse/the-pass-h2-harmonic-generator/
I know this article. But at the very end he writes:
It tends to sound best when presented by fairly simple audio material at levels your neighbors don't complain about. Massive orchestras and large choral performances at high levels can get congested when the 2nd harmonic is
That's the point where I say no. I do not listen regularly to typical audiophile recordings like you hear at audio shows.
 

omad

Member
Joined
Dec 12, 2023
Messages
8
Likes
3
Location
Western Australia
This is probably too old and not going to get noticed, but I picked up one of these recently and the sound is pretty amazing. I'll likely be comparing with a friend's topping soon.

The main reason I came to comment, is that literally everywhere else that I looked at surrounding this DAC agreed that the USB input was more of an afterthought and average at best, to generally awful at worst, with the coax SPDIF being noticeably better, and the main use case of this DAC. This may be the case for more of the audio-gd gear.. ? Is there a reason that USB only is used?

Just a thought.

Apologies if this has already been raised, I did try to search the thread.
 

VintageFlanker

Major Contributor
Forum Donor
Joined
Sep 20, 2018
Messages
4,943
Likes
19,699
Location
Paris
Welcome,

Is there a reason that USB only is used?
The fact that the brand trumpets the presence of Amanero USB interface (which, by the way, absolutely sucks), maybe ?
Anyway, I measured the NFB-11.38 Performance Edition and it wasn't any better than this one (Toslink in fact was better, other inputs encountered serious ground loop issues).
I'll likely be comparing with a friend's topping soon
Proper blind test, or pointless comparison. ;) Also, beware that the AGD outputs 2.5+Vrms (as most AGDs do) where the Topping is perhaps only 2V unbalanced.
Edit: some Topping indeed are capable of 2.5Vrms with RCA.
 

omad

Member
Joined
Dec 12, 2023
Messages
8
Likes
3
Location
Western Australia
Thanks, much obliged.
The fact that the brand trumpets the presence of Amanero USB interface (which, by the way, absolutely sucks), maybe ?
Anyway, I measured the NFB-11.38 Performance Edition and it wasn't any better than this one (Toslink in fact was better, other inputs encountered serious ground loop issues).
Yeah, fair enough. I'm still relatively new to the hobby (couple years, maybe, of being more 'serious') and very new to DACs. I got the DAC, Audiophilleo and curious cable (no idea if they'd make the difference, still not sold on a USB cable making the sound better... ?) second hand fairly cheaply, just to dip my toes in, as I've primarily been using my a3080 as the DAC/media device. From there to a power amp and a set of Tannoy Precision 6.4 - all of which I was already mostly happy with.

Apart from not being able to run the sub, the NFB-2 completely blew the a3080 out of the water (with 2 channel music that has great imaging). Went from feeling like I'm in the room with the artist to felling like they are basically sitting on my face.
Proper blind test, or pointless comparison. ;) Also, beware that the AGD outputs 2.5+Vrms (as most AGDs do) where the Topping is perhaps only 2V unbalanced.
Edit: some Topping indeed are capable of 2.5Vrms with RCA.
Haha. Likelihood of proper blind test I think is probably low. I don't really have the facility to quickly and easily switch sources. Since hearing the difference of this DAC combo, now trying to work all that out without breaking the bank.... again. At the moment I'm literally swapping RCA's at the amp, it's the picture of modern convenience!

I tend to try not to be biased, I've discovered a lot of 'weaknesses' in my setup(s) over time and once I hear something 'better', it's really hard to go back.
 
Top Bottom