peace of technology
I'm always entertained seeing a new, possibly usable, and interesting phrase accidentally coined.
peace of technology
I'm always entertained seeing a new, possibly usable, and interesting phrase accidentally coined.
Problem with such designs is they usually cost more and there is little they can offer to justify that, unless you can find pleasure in owning such "exotic" peace of technology.
I own both the H2O and the A20H, reading what you wrote made me laugh a lot.This is a review and detailed measurements of Gustard A20H DAC and headphone amplifier. It is on kind loan from a forum member. It retails for USD $850 on Amazon with free shipping (from China?). I am accelerating this review because it is on sale on massdrop for USD $700. Still not cheap but more reasonable.
For your extra money you get a much larger and beefier enclosure with a large LCD display:
I usually clean the units and touch them up in photoshop but in this case I choose to leave it alone so that you can see how well it shows smudges and scratches. Overall the enclosure is bland but OK.
Claim to fame of this unit is stepped attenuator implemented using a bunch of relays. The volume knob therefor is a rotary encoder telling the unit where to set the volume. And therein lies the main usability issue I found: if you rotate the knob quickly, it will change very slowly! This is of course the opposite of what you want. If I play a loud track, or after I have changed to a more sensitive headphone, I want to be able to rapidly turn the volume down. If you do that, the counter on the display changes very slowly (once a second?) as will the volume. You have to rotate the knob at a slow to medium rate to get it to change quickly.
Other than this, the menus are easy to navigate with up/down and knob to change setting.
For this testing, I am only using USB input. I tested both balanced XLR and unbalanced RCA for most of the tests. Let's see how she did.
Measurements
As usual we start with our dashboard view:
View attachment 18728
Our distortion measurement falls a bit short of published measurements. But if you look at the fine detail, you see that Gustard measurements are at -6 dBFS, not 0 dBFS as I test. Due to loudness compression, we tend to get a lot of music that reaches 0 dBFS so I like to see good performance at the limit. This puts the unit at the bottom of tier 2 of performance as far as distortion:
View attachment 18729
As you see on that graph, unbalanced produces about 3 dB lower performance.
Dialing down the level to -6 dBFS as Gustard has done, improves performance pushing SINAD to 108 dB using balanced connection.
We can see this issue immediately when we run our intermodulation distortion test versus level:
View attachment 18730
We see how both outputs start to rise in distortion levels as we approach 0 dBFS. This is likely due to the output buffer stage saturating.
As the A20H uses the AKM Dac chip, its performance almost mirrors that of Topping DX3Pro.
Jitter distortion and noise is a bit disappointing although not of audible consequence:
View attachment 18731
An ideal DAC would just show the main tone at 12 kHz and nothing else. Here, we see tons of jitter and distortion spikes in both balanced and unbalanced outputs.
Gustard A20H nails the linearity though showing that it produces correct voltages all the way down to -120 dB (20 bits):
View attachment 18732
That's the DAC performance. Let's switch to its headphone output and see what power we get with a 300 ohm dummy load using 1/4 inch unbalanced output:
View attachment 18734
This is a disappointing showing. The unit falls short of the performance of Topping DX3 Pro which retails for nearly 1/4 of it. It has both higher noise and distortion and less power.
Switching to 33 ohm load, we get this:
View attachment 18735
We see slightly better showing here but still nothing to justify paying more.
These values are far below the power specs from Gustard:
View attachment 18736
Of course they have no details as to how these power numbers were computed. Perhaps they are for "balanced" XLR headphone out? Let's test that at 50 ohm:
View attachment 18737
OK, we finally get decent amount of power. At 50 ohm, I am seeing nearly 1.7 watts which if one interpolates from the specs, seems correct.
Channel balance is excellent due to digital control of volume/stepped attenuator:
View attachment 18738
Likewise output impedance is a low 0.7 ohm which means it can drive just about any headphone without changing its frequency response:
View attachment 18739
Listening Tests:
As usual, I started testing using my Sennheiser HD-650 whose 300 ohm impedance let's us compare the objective results with subjective listening. Here, there simply was not enough power. I could dial the volume to max of "60" and while it was loud, it just wasn't enough. Base impact simply was not there. Switching to Topping DX3 Pro, there was an authority and headroom that was quite satisfying and lacking in Gustard A20H.
Next I switched to HifiMan HE-400i which with its 40 something impedance, attempting to match the objective to subjective again. Due to more available power at this low impedance, the situation was improved but I still preferred the Topping DX3 Pro. There was a bit more power in Topping and I got the impression of better resolution (could be placebo).
Conclusions
If you plan to use the normal 1/4 "single-ended" output of Gustard A20H, my advice is to save your money and get much cheaper products such as Topping DX3 Pro. You actually lose both performance and out of pocket money by using Gustard A20H.
Balanced mode has a lot more power but I can add a superb headphone amp such as JDS Labs Atom or Massdrop THX AAA 789 and be way, way ahead. It will be a two-box solution so if you want a tidy desk, and money is not a concern, then I guess the Gustard A20H fills that gap.
Overall, the A20H is not a bad unit and seems to have decent engineering. I just can't figure out what it does all that better to justify its premium.
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As always, questions, comments, recommendations, etc. are welcome.
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Meaning what?I own both the H2O and the A20H, reading what you wrote made me laugh a lot.
It doesn't matter what it looks like. It matters how it treats the audio signals you hear which is what the measurements are about. Once you know that, then you can pick on basis of looks, features, price. Audio marketing people love for you to just go by those non-audio factors. Don't fall prey to them....Every opinion must be respected, but when some devices are told as top class and opening the box we found something similar much more to a toy than a hi fi equipment...
1, Have you heard dx3pro? No?Beg Your pardon,this is only an audiophile's opinion:
I'd like to stay quite and keeping on enjoying music, but, cannot agree with the method of the analysis at all ,infact, in spite of the abudance of measuraments,which frankly don't impress me much,..there is no enough space for serious listening tests.The better path is the "Santo Graal"of every constructor...but have never seen even middle class products ,built in a poor way, so a good hardware cannot be avoided.
What counts is music , the richness,the dynamics,the way make you thrill, getting close to hurt your ears, but finally,caressing, the emotions that can rise.. .Well...it has been at least 35 years I have been spending time and money in every kind of equipments,whith a lot of Joy and torment. but it is difficult to accept, that you don't listen to and neglect the balanced output...I REMENBER YOU THAT THIS DEVICE IS MEANT TO BE PLAYED IN BALANCED CONFIGURATION ,a territory unknown for your cheaper and miracoulous objects. THESE ARE NOT DETAILS!!Just like,discrete components,class A,high current.
If You only trust in meausuraments , can analyze a pair of tubes monoblocks and discover that a whatsoever masssdrop is better...take it in count,if You want give a good service.please.
Moreover,the A 20HGustard can act as a good simple transparent and neutral preamp ... balanced naturally.
Finally indeed,for this last and more other reasons ,the products are not comparable at all.
Best Regards
Dan
1, Have you heard dx3pro? No?
2, Are you just trying to justifying all your purchases in the past?
3, Time is different now, there weren't products with this level of performance. Not available. But it's going far far away from what it was. It's getting really really good.
4, If you want to spend more money for same performance. Sure, go ahead, whatever makes you happy.
I agree on half. But subjective evaluation is the key of learning and progress. Objective measurements alone won't lead you to anywhere. Also more and more "snake oil" are objectively evaluated as beneficial. There are always reasons for those things. And audibility is not as easy as described before. Anything measurable should be considered audible. We should constantly measure and listen and progress.I would agree with the idea that what really matters is the music and the emotions created by the experience of listening to music (or spoken word etc). That is art. However, designing and manufacturing audio equipment is not art, it is science and engineering and measurement and analytical tools really can evaluate performance far more effectively and reliably than golden ears. The objection to measurement and objective evaluation from many audiophiles is I think a reaction to such techniques highlighting a lot of audio myths and snake oil for what they are.
I have a cold right now and my ears are plugged. My instruments never catch a cold. If a device can't do justice to a simple sine wave, it can't do justice to complex music. My analyzer works a million times better in analyzing that sine wave than my ears can. It would be like asking your doctor to not use an X-ray machine and just look at you to tell you what is wrong with you. You don't tell him that, so don't tell me the same.I'd like to stay quite and keeping on enjoying music, but, cannot agree with the method of the analysis at all ,infact, in spite of the abudance of measuraments,which frankly don't impress me much,..there is no enough space for serious listening tests.
My analyzer works a million times better in analyzing that sine wave than my ears can.
thank you for this review, amirm.
this review & conclusion is exactly same what I feel when I change to topping dx7 from gustard a20h
meh power(60 step volume is quite narrow and starting volume was too loud for me...), meh quality of sound, good manufactured hardware...
item don't have that much points to buy. I had felt wasting my money about price & performance.
in addition, while I was using a20h, it was really hot. not warm, really hot... that's another bad point.
Yeah the Gustard A20H's headphone section is not good at all, I had to buy a separate headphone amp. I tried the Topping D70 as a standalone dac (same chips as the A20H, dual mono as well) since everyone was praising Topping, but was very disappointed. The lack of punch was obvious compared to the A20H, which I kept in the end. The Topping was a little bit better at instrument separation though.