Review and Measurements of Audio-gd NFB28.28 DAC and Headphone Amp

[VintageFlanker]

Nope. I own an R2R-11 myself, the only thing the "warm" jumper do is to roll-off the high frequency. The DAC is still operating in NOS mode, regardless of the jumper settings (neutral/warm). Neutral jumper sounds great to my ears.

Ok, my bad. I just edited my post. So this was only an analog tuning at last.

 

[bunkbail]

That's one option. There's many others though, I have used SoX on foobar before which is also available on Pi-hats. SoX is great and free

I use SoX-vhq (PulseAudio) on my Linux box myself (system-wide setting). The perceived sound quality improvement is minimal but I use it anyway.

 

[Veri]

I use SoX-vhq (PulseAudio) on my Linux box myself (system-wide setting). The perceived sound quality improvement is minimal but I use it anyway.

Any good DAC will have proper filtering off its own after all. I don't believe filters can make much of an audible difference (if any), anyway.

 

[Jimster480]

Not surprising that once again this is a horribly measuing device....

Props to @amirm because hes delivering reviews so consistently that I am literally on this site every day reading and learning at this point in time.

These "hifi" brands better all run and hide! None of them are safe out here anymore!

Make good products or Amir will come for you! YOU HAVE BEEN WARNED!!!

 

[Jimster480]

I'm happy I sold my NFB28, v2015 version. It was not awful sounding, but when my D10 arrived, I realized that the D10 sounded just as good, if not better (the differences are hard to hear, if it's possible at all), and cost a small fraction of the NFB28. I should have sent it to Amir first, but this one is a newer version with similar design, and my bet is it would have tested just as badly.

Kingwa is a nice guy, always responsive, but he's making claims his gear does not seem to back up. He could do better if he chose to, I'm sure.

When I shopped AudioGD (after hearing immeasurable praise from head-fi) I contacted Kingwa and he told me BS that makes no sense (I can post the whole conversation here). When I asked him about the difference in the different models he tried to claim that he couldn't explain the differences because he doesn't speak english well. So I had my Chinese friend write the entire question to him in chinese and he basically said something that means nothing.

 

[mshenay]

I can't speak for any of the new gear, but I've got an NFB 10ES2 as my primary dac and I run it exclusively on Low Gain. Swapping into High Gain does make it sound, horrid.

All in all it's not terrible, measurements aside, I've found it subjectively better than quite a lot of other gear including stuff like the Hugo 2 from Chord. Though I run it Coax in via a Etir and with a power conditioner. The USB performance and Optical input are atrocious too

Either way, I hope to also have an RME ADI 2 for my self here soon!!!

 

[restorer-john]

Swapping into High Gain does make it sound, horrid.

The USB performance and Optical input are atrocious too

If this is indeed the case, the product is poorly designed or faulty.

 

[Jimster480]

I can't speak for any of the new gear, but I've got an NFB 10ES2 as my primary dac and I run it exclusively on Low Gain. Swapping into High Gain does make it sound, horrid.

All in all it's not terrible, measurements aside, I've found it subjectively better than quite a lot of other gear including stuff like the Hugo 2 from Chord. Though I run it Coax in via a Etir and with a power conditioner. The USB performance and Optical input are atrocious too

Either way, I hope to also have an RME ADI 2 for my self here soon!!!

Ouch man, I can only imagine the RME ADI 2 is going to blow your socks off just out of the box compared to performance like this xD

 

[andreasmaaan]

I can't speak for any of the new gear, but I've got an NFB 10ES2 as my primary dac and I run it exclusively on Low Gain. Swapping into High Gain does make it sound, horrid.

All in all it's not terrible, measurements aside, I've found it subjectively better than quite a lot of other gear including stuff like the Hugo 2 from Chord. Though I run it Coax in via a Etir and with a power conditioner. The USB performance and Optical input are atrocious too

Either way, I hope to also have an RME ADI 2 for my self here soon!!!

The ADI-2 should sound no different from the Hugo 2. They both have a SINAD of well over 100dB, so any distortion/noise they produce could not possibly be audible. The only possible difference will be the RME's higher output power, although it sounds unlikely you'll need it given you're coping ok with the NFB 10ES set to low gain.

 

[Addicted to music]

@andreasmaaan

there’s a particular individual who is technically very competent on another forum swears by the Audio gd 7 series with the 1704 chips.

 

[andreasmaaan]

@andreasmaaan

there’s a particular individual who is technically very competent on another forum swears by the Audio gd 7 series with the 1704 chips.

I had one of those at one point actually. I think it was Ref 7, maybe Ref 7.1. Anyway, the original one that had 8 x PCM1704.

I quite liked it. Very weighty, solid kind of sound was my impression, although not the cleanest/clearest (that's obviously to be taken with a grain of salt so many years later). It seemed to suit my system well at the time, which was a bit lean due to the room/speaker combination I had, but I wouldn't particularly recommend it in general.

 

[VintageFlanker]

The ADI-2 should sound no different from the Hugo 2. They both have a SINAD of well over 100dB, so any distortion/noise they produce could not possibly be audible. The only possible difference will be the RME's higher output power, although it sounds unlikely you'll need it given you're coping ok with the NFB 10ES set to low gain.

Hum. I beg to differ. Both the Qutest (not the Hugo 2) and RME were at home last week. Using RCA Line Out (2V Incisive Neutral HF Roll Off for Qutest vs +7db SD Sharp for RME) They do sound nothing similar to my subjective hear. The Qutest is way brighter and I simply can't listen to it at high level, while it has significantly wider soundstage, in the other hand. The RME sounds more balanced and smoother.

Needless to say, for 500€ less (and far more settings), I sent back the Qutest and kept the ADI-2 DAC.

 

[andreasmaaan]

Hum. I beg to differ. Both the Qutest (not the Hugo 2) and RME were at home last week. Using RCA Line Out (2V Incisive Neutral HF Roll Off for Qutest vs +7db RME SD Sharp for RME) They do sound nothing similar to my subjective hear. The Qutest is way brighter and I simply can't listen to it at high level, while it has significantly wider soundstage, in the other hand. The RME sounds more balanced and smoother.

Needless to say, for 500€ less (and far more settings), I sent back the Qutest and kept the ADI-2 DAC.

Ok, but was your listening blind and level-matched?

 

[Addicted to music]

I had one of those at one point actually. I think it was Ref 7, maybe Ref 7.1. Anyway, the original one that had 8 x PCM1704.

I quite liked it. Very weighty, solid kind of sound was my impression, although not the cleanest/clearest (that's obviously to be taken with a grain of salt so many years later). It seemed to suit my system well at the time, which was a bit lean due to the room/speaker combination I had, but I wouldn't particularly recommend it in general.

Do you remember I brought a M51 and set of Beringher 3031A and forgot the remote for the M51.
Yes you’re right very different. I do remember it was a very impressive sound, but I did say to myself that in actually life the instruments were exaggerated and unrealistic.

 

[andreasmaaan]

Do you remember I brought a M51 and set of Beringher 3031A and forgot the remote for the M51.
Yes you’re right very different. I do remember it was a very impressive sound, but I did say to myself that in actually life the instruments were exaggerated and unrealistic.

Funny that At the same time I had the Ref 7, I also had an M51. Those two DACs definitely seemed to sound quite different from each other. The Ref 7 sounded bigger and weightier, the M51 sounded lighter and cleaner IIRC (again to be taken with a huge grain of salt as I was listening sighted and not level-matched).

 

[VintageFlanker]

Ok, but was your listening blind and level-matched?

No blind test but A/B comparaison. Almost level matched. Qutest set to 2V and RME set to Ref Level +7db at 0db which, according to RME correspond to 1,8V. To my hear, I could not say one unit was louder than the other. They do sound different, however. RME has flat frequency response and I'm sure Qutest has little tweaks in high mids and treble which make it sound more detailed and extended but also brighter and harsher.

 

[andreasmaaan]

No blind test but A/B comparaison. Almost level matched. Qutest set to 2V and RME set to Ref Level +7db at 0db which, according to RME correspond to 1,8V. To my hear, I could not say one unit was louder than the other. They do sound different, however. RME has flat frequency response and I'm sure Qutest has little tweaks in high mids and treble which make it sound more detailed and extended but also brighter and harsher.

It's very hard to know I guess. I'd be extremely surprised if there's any actual peaks in the Qutest's frequency response, that is very unusual in a DAC and is certainly not Chord's style.

In most of these cases psychology or level imbalances between the two units (not necessarily loud enough to be consciously perceived as a difference) tend to be the decisive factors IMHO (I apply this thinking to myself too btw).

1.8V vs 2V is a difference of almost a decibel which is definitely enough to make one sound better than the other.

 

[Addicted to music]

Funny that At the same time I had the Ref 7, I also had an M51. Those two DACs definitely seemed to sound quite different from each other. The Ref 7 sounded bigger and weightier, the M51 sounded lighter and cleaner IIRC (again to be taken with a huge grain of salt as I was listening sighted and not level-matched).

I still have the NAD M51 I’ve done a few shootouts with it and I have to say it’s showing it’s age.. Not measured here but Stereophile and another EU magazine showed similar test results. I have to say that using the M51 with its digital volume control was the cleanest way direct into a power amp. The Topping D50 also show some very promising outcomes, thanks to this forum.

 

[andreasmaaan]

I still have the NAD M51 I’ve done a few shootouts with it and I have to say it’s showing it’s age.. Not measured here but Stereophile and another EU magazine showed similar test results. I have to say that using the M51 with its digital volume control was the cleanest way direct into a power amp. The Topping D50 also show some very promising outcomes, thanks to this forum.

Have you been able to hear any difference between the M51 and the D50?

 

[Addicted to music]

Have you been able to hear any difference between the M51 and the D50?

I didn’t have to hear the difference between them, when the D50 was in the rig it’s a typical ESS presentation. It’s very similar or too close to the OPPO 105, except that the 105 is “airy” audiphile speak! The M51 is much nicer and easier to the ear. And that’s level match! When the D50 is hooked up to the power amp, it’s the same presentation all the way cranked up! The OPPO 105 just gets “airy” and not in a good way.