[FredA]

I performed two sets of tests: most of the tests were with the unbalanced RCA output out the back of the unit, not headphone output. In addition to those "DAC tests," I also tested the headphone out with respect to power output and impedance. Now that you know this, please explain again what is incompetent about the data.


Once again, most of the tests are with the DAC portion alone. There, the comparison is the same as the unbalanced RCA outputs are used. Here is an example output from RCA outs, NOT headphones:

I replicated that very test to the bit and got completely (worse) results than they show on their spec page. See: https://www.audiosciencereview.com/...-dac-and-headphone-amplifier.2486/#post-71124


And my reporting/measurements show that degradation clearly. Their own specs are not at all compliant with the performance I see and paint a picture of an amplifier stage that is using feedback. That is not correct.


Please. I have been an audiophile for nearly 50 years. I am a trained listener professionally and can pass double blind tests of tiny differences that scare most people from just running the tests. Yes, my hearing is not as good as younger folks but in this case, what I hear correlates with the measurements.

Please forgive me for being blunt but being an EE is insufficient for you to know psychoacoustics. Much of the distortion we measure is masked by the music itself. I am pretty sure the differences I noted would be inaudible to many others. Please read my tutorial on audio measurements to understand what these measurements, and how audible they can be.

But you can ignore all of my listening tests and just go by the measurements. On that front, the company is well aware of my work and they have NOT produced any measurements of their own to counter them. I am happy to be corrected but not by wrong assumptions of what is measured and not having your own data to counter mine.

The manufacturers should be producing the measurements I am producing. Since almost none do, I am performing that task with no compensation whatsoever. It is just a service to the community. As such, it seems odd that you would spit on my work while defending the company. Whose side are we on anyway?

Has the unit been properly burned? What load do you put on the rca out? Not 30 ohms I hope.

This test does not correspond to any of my listening experience with audio-gd. And I trust Kingwa's measurements. The fact that you use Topping as a benchmark is not good for your credibitlity. The fact that your listening experience does not match your measurements does not help you case either. The level of distorsion you measure is a clear indication that you made a mistake. This level of distorsion would make any gear sound like garbage.

It's either trusting a complete outsider like you ou Kingwa and my own ears. So, that's a simple choice really. Measure the r2r 11 for fun i.e. arguably the best-sounding combo under 1K and show us the graphs so we can have a good laugh.

What you are doing, be it an honest mistake or not, is diffamation, plain and simple.

 

[amirm]

Has the unit been properly burned? What load do you put on the rca out? Not 30 ohms I hope.

The unit has been in use by the owner who loaned it to me so I assume it means it has been "burned." The load on RCA output is 100 K ohm.

 

[amirm]

This test does not correspond to any of my listening experience with audio-gd. And I trust Kingwa's measurements. The fact that you use Topping as a benchmark is not good for your credibitlity.

What? Feel free to ignore the Topping results and tell me what is good about what the Audio-gd achieved.

As to trusting the manufacturer's measurements, there is only one which I addressed in my post. As to your listening experience, I don't know anyone's ear that measures what an instrument does. But maybe you can tell me the THD+N percentage from what you heard.

 

[amirm]

It's either trusting a complete outsider like you ou Kingwa and my own ears.

Whatever your ears tell you is your business. They don't perform measurements and so have no bearing on objective data that I have presented which can be verified.

As to trusting the manufacturer more than me, that is your call but it is not a "fact" or anything that has merit. Ask your trusted manufacturer to repeat my test and post their results. If you or they are unwilling to do so, then we are left with my data as the only thing standing. We are talking about hard data and your feelings, etc. have no place in the discussion.

 

[Chopin75]

THD is not everything, though didn’t Audio GD admit that R2R has higher level of distortion ? What about tubes ? Of course tubes has much higher THD vs Semiconductor, but it still sound good. Let alone when comparing ESS a company that is very well known to produce world class chips on specifications. The general is that R2R has the Tubes like characteristic vs Solid state ?

This is the reason why I mentioned that the Dynamic range of ESS9038Pro configured as 2X at 140Db is not easily achieved by any other things on the market. Once adhered to the requirements, these DAC are more than likely to be lasting for a long while, probably until ESS9048Pro release in 15 years or so ?

Audio GD has good dual ESS9038Pro DAC. I opted for LKS, simply because they were the first on the market to have done it, and I am not disappointed, not at all

Of course, there are things that can surpass human hearings, and if they fail to tell, everyone lay back on psychoacoustics like you mentioned, and or they would fall back on “it can’t be bad, because it is expensive”. We already hear manufacturers who took advantage of this anology “it is expensive, because it sound good”

I am always a bit skeptical about these measurements but again I never had chance to listen and measure at same time for comparison. I just don't think measurements will ever correlate 100% with what we hear. I am no EE engineer (though my father was) but a neurologist. The sensitivity of the brain/ear is very different from the measuring instruments so it makes sense that what we hear may not be what is exactly shown on/correlated with the measuring devices (unless you are cybot/human-computer hybrid) So the device can detect more than humans can and vice versa. I believe human ears can really detect very subtle changes of tones etc,,that cannot be measured but cannot be really detecting purity of tone (free of noise distortion) unless it affects the final tonal soundscape when it comes out of the speakers/headphones. True, human perception can be affected by emotions/preconceived memory that affects his listening experience (hence psychoacoustics) but overtime with repeated listening it remains very reliable. (until you become deaf)
Also I am not sure how well machine can measure non-pure tones, meaning noise that comes with a tone production. Every instrument produce pure tones/its harmonics and also some noise, e.g noise from the plugging of guitar strings, horse hair rubbing the strings on the violin, the drum hitting is basically some organized noise (Not really pure tone) all these can be heard and felt by the ears, but can they be measured ? It also explains why digital music is so hard to sound great because digital music often eliminates these noise that is part of the music that makes the sound so much more organic....

 

[FredA]

Whatever your ears tell you is your business. They don't perform measurements and so have no bearing on objective data that I have presented which can be verified.

As to trusting the manufacturer more than me, that is your call but it is not a "fact" or anything that has merit. Ask your trusted manufacturer to repeat my test and post their results. If you or they are unwilling to do so, then we are left with my data as the only thing standing. We are talking about hard data and your feelings, etc. have no place in the discussion.

I don't trust you for many reasons including the fact you did not know that a balanced amp used in single-ended mode only outputs 1/4 of its stated max power (the rated power is clearly specified by audio-gd with this regard). That's pure ignorance for someone who pretends to be a long-time audiophile. And that part of your review was misleading and should be corrected. Another reason, call it intuition, you don't pass my smell test. You review occuring at a time when audio-gd sells nfb-11s and r2r 11s by the dozen seems strangely coincidental. Then certain acquaintance you have. Plus I have never heard of you before, You recent adhesion to headfi is the final nail as a far as i am concerned.

If you are honest and serious, as opposed to what i perceive, you should contact Kingwa about this.

 

[gk2013]

I remember very well the (one of the first) Class D amplifiers. The advertisement was all about how good they measure at that time. Spectacular specifications! The sound was not.
I also remember my first vacuum valve amplifier. Sounded beautiful. I loved it. If I would have measured it it probably would be pretty bad.
amirm likes measuring and takes his conclusions from it. Good for him, enjoy it or not.
The hole freaking problem is how you measure a e.g. analogue interlink? Why do they sound different when you compare? Why do we hear differences?
Oh, no, amirm measured them and they are all the same! You can't hear any difference of course!
Sleep well amirm

 

[amirm]

I don't trust you for many reasons including the fact you did not know that a balanced amp used in single-ended mode only outputs 1/4 of its stated max power (the rated power is clearly specified by audio-gd with this regard).

Clearly specified? You mean this?

What is the distortion level used for determining the power level? Not specified.

Are both channels driven or one? Not specified.

It is true that they say balanced. Just as well I was clear that I measured it unbalanced mode which they need to specify but have not.

The key thing here is that single number power specs are useless. I provide a full measurement graph of power versus THD which is the correct way to do it. Anything else is marketing fluff.

 

[amirm]

I remember very well the (one of the first) Class D amplifiers. The advertisement was all about how good they measure at that time.

Class D amps did NOT measure well when they came out. Most of them still don't compared to classic AB or A amps. Yes, Bruno's amps have good measurements but that is not true of most class D amps.

 

[amirm]

Oh, no, amirm measured them and they are all the same! You can't hear any difference of course!
Sleep well amirm

Well, I heard the difference and reported it. Alas, that difference was not in favor of Audio-gd.

For my listening tests I match levels. Without it, there is huge amount of difference in what is perceived. Match levels and a lot of the difference unfortunately goes into toilet.

 

[gk2013]

Class D amps did NOT measure well when they came out. Most of them still don't compared to classic AB or A amps. Yes, Bruno's amps have good measurements but that is not true of most class D amps.

I said this is how it was advertised. I am not sure what you are after, you probably enjoy this a lot.
I fully agree with FredA: If you are honest and serious, as opposed to what i perceive, you should contact Kingwa about this.

 

[amirm]

I fully agree with FredA: If you are honest and serious, as opposed to what i perceive, you should contact Kingwa about this.

My honesty and seriousness is a promise to consumers, not manufacturers. I either buy gear that members want to have measured, or am given loaned gear by the same. I measure them and post the results. I am not beholding to any manufacturer to go and chase them for answers. You all can do that if you like, but it is not a service I provide. Or consider it my charter to do so. I think you are confusing me with magazine reviewers who do this work as a commercial venture and have such relationship with manufacturers to get loaned equipment and such. That is not what I do.

That said, both their German distributor and Kingwa affirmatively know about my work. Here is the response from the former: https://www.reddit.com/r/headphones/comments/86vbk7/audiogd_response_to_yesterdays_measurements/

The one from Kingwa is similar in vein and as you see, neither includes any measurements to dispute my findings.

As you see in the reddit thread, I have offered my help to improve their performance and answer any questions they may have. There has not been any outreach yet. Other manufacturers have taken me up on such help in the past, leading to better products in the future. I like nothing better than to see them act in a constructive manner this way.

 

[amirm]

I said this is how it was advertised.

You said they advertised how well they measured: "I remember very well the (one of the first) Class D amplifiers. The advertisement was all about how good they measure at that time."

I am saying they couldn't have bragged this way because they did not measure so well. Instead they hung their hat on efficiency, and high amount of power.

I am not sure what you are after, you probably enjoy this a lot.

No, I rather go and measure more gear than deal with these kinds of non-constructive discussions.

 

[FredA]

Clearly specified? You mean this?



What is the distortion level used for determining the power level? Not specified.

Are both channels driven or one? Not specified.

It is true that they say balanced. Just as well I was clear that I measured it unbalanced mode which they need to specify but have not.

The key thing here is that single number power specs are useless. I provide a full measurement graph of power versus THD which is the correct way to do it. Anything else is marketing fluff.

Maybe i am wrong this one, and you did not pretend the nfb27.38 was short on annonced power. Not sure. Does not matter so much, cause the rest is all plain wrong and botched. Let me explain.

Driving the rca output at 6v is beyond what audio-gd used for their meaurements, and beyond what anyone would use in a typical setup as normal listening level. So it's pointless. Redo your measurements using 2.5V as i assume audio-gd did and correct your review. If you are honest.
As you must know, any decent power amp will be insanely loud playing a 2.5 volts signal, most will even saturate.

So, you dac measurements are pointless, as are those of the hp output. You are not trying to use a valid use case but you are rather trying to make audio-gd look bad. So again, redo all these measurement with human compatible levels or go annoy people somewhere else cause time is precious and this forum has normally a useful purpose. Go have a drink with Jimster if nothing better comes up.

 

[Chopin75]

Interesting why Class D amps don't measure well. My class D amps sound pretty smooth and clean, maybe too clean??