[sajunky]

It looks like Ares II do not have a proper 2nd order (at least) analog filter on the output, so NOS modes will carry a lot of ultrasonic noise. Amir in his tests didn't do proper wideband FFT plot, but he attached the following unconventional THD plot in response to the requests for testing NOS mode, it was in order to scare people.

The output filter looks very similar to the Audio GD R2R11, but here the output stage is made of non-feedback discrete amplifier. Denafrips don't give any details. If they use opamps, NOS mode will be affected negatively.

Other than that, I have no other option on R2R11 and it sounds fantastic. I tried upsampling 44.1kHz x4 in Foobar+SoX. The original 96/192kHz material sounds better, but for the upsampling I haven't made my mind yet.
Others with R1/R28 prefer 8xNOS for a modern top100 hitlist. For classic/jazz and all type of classical instruments NOS is prefered by many.

 

[Nickol]

It looks like Ares II do not have a proper 2nd order (at least) analog filter on the output, so NOS modes will carry a lot of ultrasonic noise.

Poorly .... Then a sad picture ...
NOS mode needs a good quality analog filter. It is a pity that Denafrips did not do this...(((

 

[Sapientiam]

What commercial NOS DAC has a sufficiently steep analog filter? I don't know of one that could keep the THD+N reading below 0.1% at all frequencies to 20kHz.

 

[sajunky]

True. And Denafrips should stop paying ASR for testing. He wrote on the beginning that the unit was supplied by the manufacturer, then he called it off saying it was a mistake and unit was supplied by the un-named member of ASR. I don't believe it was a mistake. Measurements look good unlike the other Amir tests of R2R DACs which came a surprise, but a critical wideband FFT plot is missing, perhaps in purpose, a typical manipulations found in other tests. He always tries to bend results to match his agenda. Then something turned away 180 degrees and this mischievous things came up.

I think we should stop talk about ASR (my bad, sorry) and focus on what people have to say.

[EDIT] I'd like to hear from Denafrips about design of the output stage.

 

[Nickol]

Who knows, the Audio GD R28 has a good analog output filter in the NOS mode ?
Or is it not implemented there either?

 

[Nickol]

I found information in the description Audio GD R28 , which seems to have

 

[sajunky]

Who knows, the Audio GD R28 has a good analog output filter in the NOS mode ?
Or is it not implemented there either?

The analog filter stays the same in all modes (OS and NOS). It doesn't makes sense to make it switchable. It would be very difficult anyway, by example in cases when a filter is placed before I/V conversion.

I can answer your question regarding A-GD R2R11. It will be probably the same with R1 and R28. From the wide-band noise FFT plot on the ASR can quess that it is the same first-order (6dB/Oct) filter as on the Ares II. The same first-order filter is also present in a new Holo May. I am attaching a May graph, as it shows all OS, NOS ad DSD modes on the same plot.

A scale is different as a sampling rate, but you should be able to pickup that it is the same filter. A wide-band THD plot for Ares II is made by Amir for a malicious reason. Any electronic engineer knows that even the best testing equipment will display wrong results when testing THD in a presence of so much wide-band noise. This is what I wanted to say in my first post.

My main question is not about the filter (as I knew it was very common), but how the Ares II output stage is designed. Hope we get some answers from Denafrips soon. And of course I am very interested in a listening comparison of Ares II and A-GD R1 in NOS mode as requested by other members.

 

[VintageAudio]

I'll provide more thoughts when I've properly A/B'd. I definitely like its sound more than the RME, but the RME has other major advantages with all its configurability, meters etc. For now its going to be a compliment for me as I like to tinker around with the sound and with both, I have 2 options.

I just watched Josh Valour's latest video on the Monoprice THX Dac - you should give it a watch. In it, he does a sound demo for Dirac Sensaround option on and off. If I were to describe the difference between the Ares II and the RME, it'd be like switching on/off Dirac Sensaround. It alters the soundstage and imaging so that sounds from primarly on the sides get stretched out. Vocals more in front and instruments a little more segregated and back slightly.

I wonder if that's what the ARES II is doing inside. It sounds very much like that. The ARES II also has a smoothness to it that I like which doesn't sacrifice detail.

Still waiting for my XLR switchbox to arrive so I can do comparisons easier.

Ok, switch box finally arrived to allow me to more fairly compare the ARES II and ADI-2. In summary, the differences are extremely subtle. Outside of a shift in the soundstage between the 2, there is no difference. Sound quality is the same.

Between DACs I used to hear more significant differences between them, when listening to them with their native amps. Some were warmer, others sharper, others more sibilant, more detailed etc.

Ever since I got my THX AAA 789, I have a much harder time telling DACs apart. This leads me to 2 ideas. The THX homogenizes sound, makes everything sound similar...or the coloration/differences in the DACS I used to notice was mainly due to the coloration in the built in pre-amps/amps in the DAC.

From my own experiences, its seems like the biggest impact you can make on your sound (assuming the same digital file), is the quality of your headphones, next your amp and 3rd the DAC.

Unless you are A/Bing, I don't think the differences between the ADI-2 and ARES II matter so much. There's a change in sound stage for sure, but this comes down to taste and also for some songs, you won't even notice the sound stage shift. For some songs, they sound better with the tighter sound stage that the ADI-2 has.

So from a sound quality perspective, I'd say both DACS are equal. With the ADI-2 you gains some benefits from the other features - mainly the configurability and cool display.

My Susvaras are end game cans, time to shop for an end game AMP and I'll live with both of these DACS.

 

[Relaxasaurus]

Ok, switch box finally arrived to allow me to more fairly compare the ARES II and ADI-2. In summary, the differences are extremely subtle. Outside of a shift in the soundstage between the 2, there is no difference. Sound quality is the same.

Between DACs I used to hear more significant differences between them, when listening to them with their native amps. Some were warmer, others sharper, others more sibilant, more detailed etc.

Ever since I got my THX AAA 789, I have a much harder time telling DACs apart. This leads me to 2 ideas. The THX homogenizes sound, makes everything sound similar...or the coloration/differences in the DACS I used to notice was mainly due to the coloration in the built in pre-amps/amps in the DAC.

From my own experiences, its seems like the biggest impact you can make on your sound (assuming the same digital file), is the quality of your headphones, next your amp and 3rd the DAC.

Unless you are A/Bing, I don't think the differences between the ADI-2 and ARES II matter so much. There's a change in sound stage for sure, but this comes down to taste and also for some songs, you won't even notice the sound stage shift. For some songs, they sound better with the tighter sound stage that the ADI-2 has.

So from a sound quality perspective, I'd say both DACS are equal. With the ADI-2 you gains some benefits from the other features - mainly the configurability and cool display.

My Susvaras are end game cans, time to shop for an end game AMP and I'll live with both of these DACS.

Great summation, thanks for posting this. Honest question though- since they sound so similar what's the point of having both DACs, or more than one DAC in general? Seems like it would be a wiring nightmare, especially with multiple amps.

 

[ActuallySparky]

...
Ever since I got my THX AAA 789, I have a much harder time telling DACs apart. This leads me to 2 ideas. The THX homogenizes sound, makes everything sound similar...or the coloration/differences in the DACS I used to notice was mainly due to the coloration in the built in pre-amps/amps in the DAC.
...

I suspect it isn't THX homogenizing sound given that Currawong called out the 789 as a reasonable amp for comparing DACs. That being said, in general I agree with you that headphones and the amp seem to be more impactful to the sound than a DAC when everything is changed in isolation.

Thanks for the detailed writeup BTW. It's making me question if I should try to budget for an Ares, or just be happy with my Bifrost 2.

 

[VintageAudio]

Great summation, thanks for posting this. Honest question though- since they sound so similar what's the point of having both DACs, or more than one DAC in general? Seems like it would be a wiring nightmare, especially with multiple amps.

Relaxasaurus, you're right. Originally, I thought the Ares II and ADI-2 would give 2 flavours of sound - a more clean, neutral, accurate sound from the ADI-2 and a more analog, warm, smooth, holographic sound from the Ares II. This was not the case from my experience.

I'm actually going to ditch the switch box. Despite it claiming to not impact the sound, it added distortion. The quality is better directly plugged in.

I have more than 1 setup so I plan to use the Denafrips / 789 for one of my workspaces and the ADI-2 on the other.

To get my warm, analog-ish fix, I add a tube pre-amp into the signal path so I can swap between solid-state and tube. My DIY version of the IFI iCan Pro. I really liked easy of which I could do solid state, tube and tube + with that amp.

 

[VintageAudio]

I suspect it isn't THX homogenizing sound given that Currawong called out the 789 as a reasonable amp for comparing DACs. That being said, in general I agree with you that headphones and the amp seem to be more impactful to the sound than a DAC when everything is changed in isolation.

Thanks for the detailed writeup BTW. It's making me question if I should try to budget for an Ares, or just be happy with my Bifrost 2.

Well, I'm also not saying that all DACS are created equal. The ADI-2 and Ares II are both DACs that are in a similar price bracket and measure well. They are both really clean. When I compare those two to lower tier dacs, tonally they may be similar, but the cheaper dacs are much more coarse in sound.

I would check out some reviews. From the ones I have seen the reviewers are able to tell that the Ares II sounds better than many other R2R dacs. I think we're all benefitting from the advances in technology and the law of diminishing returns. You'll have to spend way more now just to get a noticeable difference in sound quality.

I'm guessing to punch above this ~$1000 USD DAC tier, you'd have to spend $3K-$4K to get something better like the Terminator, which is still considered a bargain relative other brand top end DACS. I'm using my DACS for desktop setup, so I don't want a huge space eating chassis in my workspace to listen to headphones. Seems counterintuitive.

 

[robo24]

In summary, the differences are extremely subtle. Outside of a shift in the soundstage between the 2, there is no difference.

Sorry if I missed it elsewhere, but could you say what that difference in soundstage is?

 

[Sapientiam]

A wide-band THD plot for Ares II is made by Amir for a malicious reason. Any electronic engineer knows that even the best testing equipment will display wrong results when testing THD in a presence of so much wide-band noise.

It isn't wide-band noise though, its specific image tones. For example in measuring THD at 15kHz you're normally assuming that once you notch out the fundamental what's left is only 30k/45k/60k etc. But in the case of a NOS DAC with only minimal (6dB/8ve) filtering there's a massive component at (44.1k-15k) = 29.1kHz only ~10dB down on the fundamental. So a naive 'THD' reading would show around 30% distortion but it sure as hell isn't harmonic distortion.

 

[sajunky]

It isn't wide-band noise though, its specific image tones. For example in measuring THD at 15kHz you're normally assuming that once you notch out the fundamental what's left is only 30k/45k/60k etc. But in the case of a NOS DAC with only minimal (6dB/8ve) filtering there's a massive component at (44.1k-15k) = 29.1kHz only ~10dB down on the fundamental. So a naive 'THD' reading would show around 30% distortion but it sure as hell isn't harmonic distortion.

You are right, thanks for correcting. I looked at a review of a Khadas Tone Board where a test was taken. People asked questions, I turns up to be a log sweep. At a different 44.1kHz sampling, but it is not a big issue. https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-wesiontek-khadas-tone-board-dac.4823/page-7

However I wouldn't speculate which part of THD constitute a DAC real distortions and which part gives the analyzer. It is impossible to estimate and it doesn't make any sense. Our ears would detect anything above 2%. A test like that is completely pointless, it is a malicious amateur work. DSD decoder wouldn't show any better. .LOL.