SMSL SU-10 DAC Review

[staticV3]

They’re publishing SINAD of 127, which based on Amir’s earlier posts seems to exceed the limits of current measuring gear if I’m understanding him correctly.

It exceeds the APx555's capabilities standalone, but WolfX-700 already measured the D90SE at 127.35dB SINAD using the Cosmos APU + APx555.

 

[PeteL]

I’m in agreement with your posts as a rule, but I’m not sure I think everything beyond 44.1/16 is snake oil—that seems a bit extreme in the dogmatic sense, dontcha think?

No doubt it’s arguable whether the vast majority of folks can hear the difference between Red Book and hi res audio, but that doesn’t mean that no one can, or that DAC manufacturers and streaming services are ripping us off by offering higher sampling rates. If that were true then the whole principle of reviewing DACs on here would be fraudulent above 96db!

I don't have a definitive view on this, but I'd put an hypothesis out here. Many times here we read variations of "If there are audible differences, it's because of the mastering" This makes sense but here's the thing. "Mastering" is not solely a creative and artistic process. There are tons of technicalities involved, and the process of working with high res /24 bit release in Red Book has been the norm for decades, it evolves, the same ways DACs to deliver them also evolves. It's not so long ago that the reconstruction filters where analog.
The ADCs are not equal, we care about the reconstruction filters, but what about the ADCs filters, what if in many cases the process of down conversions creates artefacts due to rounding errors, unequal dithering process, etc, etc.

Bottom line, Original working masters are in most case 88k or more and are 24 bits for many reasons that do make a lot of sense when working production. Analog masters are transfered in High Res or DSD first. To deliver RedBook, you have to down convert. People worry about lossy? Well we are listening since the CD came up to a very lossy format. The released format is less than half what the original studio master was. Down converting is at the very end of the process, for good reasons. So yes it is "mastering" but it seems very plausible to me that in many case, not all, that down conversion would create artefacts especially if the CD master is a decade old or more. In theory, the Redbook standard may be all we need, but theory and practice is different. You are doing mathematical operations to reduce the size of what was the "original" master. It may have been done with no artefacts, but it really likely have been done with a process that does especially if it have been done more than a few years ago. The High Res tech may not be superior today, but if you are listening CD quality, you are listening to a processed version, not the original, and you don't know exactly how good this process was.

 

[mdsimon2]

I am not an expert in the realm of electrical engineering, I am an acoustics guy, So very much open to correction here.

I would assume that a digital attenuation (i.e. before the D>A conversion takes place) would allow the inherent idle noise floor of the converter to remain at a constant level regardless of volume position. Thus, as you decrease the output volume digitally, the noise floor remains constant; therefore, the ratio between noise and the signal shrinks, and you lose "performance"

In analog volume control (referring to attenuation post D>A conversion, (obviously many use a "digital" encoder to control a resistor matrix), would not only attenuate the signal but would also (in a "technically ideal" sense) attenuate the noise floor of the device.

Overall your understanding is good but you need to run the numbers to see the practical implications. You also need to consider that in the analog case you will still have some noise floor from the DAC/volume control even if it is very low and this will be multiplied by the amplifier. The amplifier itself will also contribute some noise.

Let's say we had a theoretical digital domain volume-controlled DAC with a -120db noise floor at full output. Let's say you turn it down to -40db. Now your noise floor would sit around -80db below the 40db attenuated signal. So you've theoretically lost 40db of SNR due to the fact the main signal has been attenuated but the noise floor has remained constant.

If we had an otherwise identical analog volume DAC that also managed -120db SNR at full output, lowering the output by 40db would not only (theoretically) lower the main signal to -40db but it would also lower the noise floor down to -160db (compared to full output). So in a theoretically perfect world, your SNR would be retained.

This example is a bit different than the one originally proposed as you are now talking about a noiseless analog volume control on a 120 dB SNR DAC whereas your original claim is that your XDA-2 would beat a high SINAD DAC at attenuated volume levels.

It is still a good one to talk through as it will show all the calculations that go in to system SNR and show how good digital volume control is. Let's use the same Purifi amp (107 dB SNR at 4.47 V output, 20 dB gain) in this system as it will help exaggerate the differences. Let's look at three cases, 1) digital volume control, 2) analog volume control with 0.5 uV residual noise (equivalent to 132 dB SNR at 2 V) and 3) 4.5 uV residual noise (equivalent to 113 dB SNR at 2 V or roughly your XDA-2).

Digital Volume Control
DAC residual noise = 2 x 10^(-120/20) = 2 uV
amplified DAC residual noise = 2 x 10^(20/20) = 20 uV
amplifier residual noise = 4.47 x 10^(-107/20) = 20 uV
total residual noise = sqrt(20^2 + 20^2) = 28.3 uV
amplifier output at -40 dB = 2 x 10^(-40/20) x 10^(20/20) = 200000 uV
system SNR at -40 dB = 20 x log (200000 / 28.3) = 77.0 dB

0.5 uV Analog Volume Control
attenuated DAC noise at -40 dB = 2 x 10^(-40/20) = 0.02 uV
combined DAC/volume control noise at -40 dB = sqrt(0.02^2 + 0.5^2) = 0.50 uV
amplified DAC/volume control noise = 0.50 x 10^(20/20) = 5.00 uV
total residual noise at -40 dB= sqrt(5^2 + 20^2) = 20.6 uV
system SNR at -40 dB = 20 x log (200000 / 20.6) = 79.7 dB

4.5 uV Analog Volume Control
combined DAC and volume control noise at -40 dB = sqrt(0.02^2 + 4.5^2) = 4.5 uV
amplified DAC/volume control noise = 4.5 x 10^(20/20) = 45 uV
total residual noise at -40 dB = sqrt(20^2 + 45^2) = 49.2 uV
system SNR at -40 dB = 20 x log(200000 / 49.2) = 72.2 dB

In the digital case system noise floor is constant and does not change with volume level. Residual noise from the amplifier itself and amplified residual noise from the DAC have equal contributions to total residual noise. You can see that this example exactly matches the -40 dB SNR in my previous plot for digital volume control.

In the 0.5 uV analog volume control case attenuating -40 dB greatly reduces the noise contribution from the DAC as expected. Amplifier performance dominates total residual noise and as the digital volume control case was so low noise to start with the difference to the digital volume control is only 3 dB.

In the 4.5 uV analog volume control case the additional noise from the volume control now dominates over the amplifier noise. As a result the performance is worse than the digital volume control. You can see that this example exactly matches the -40 dB SNR in my previous plot for analog volume control.

The issue I don't quite understand with the graph is how the "analog" volume control is tracked at a parallel slope to digital. You'd think that any introduced noise of including an analog attenuation circuit vs Digital would be at a fixed/constant level.. Assuming the noise introduced by the resistor ladder is above that of the actual DAC, you'd theoretically expect a perfectly straight line for analog, showing that the analog attenuation noise is the "bottleneck" per se.

This is not true, in all cases you have some constant analog noise floor and as you reduce level you reduce the output side of the SNR calculation so the SNR will go down, even in the analog case.

I would have thought the graph would look something like this. the digital DAC outperforms the analog DAC (at close to max output, since the analog resistor stage might introduce low-level noise over a direct digital DAC) and then once the SNR of the digital volume DAC degrades, the analog volume DAC quickly outtakes it, being limited by the bottleneck of its analog resistor stage.

You get something closer to what you describe with lower performance DACs. Here is a plot for a 100 dB SNR at 2 V DAC with that 4.5 uV analog volume control compared against digital volume control. Clearly analog wins at all volumes other than at very low attenuations.

Or to view it another way here is residual noise for the same case.

In conclusion I think these examples show that analog volume control is more important if you are starting with a low SNR DAC as it greatly increases performance at attenuated levels BUT if you are starting with a very high SNR DAC then it really does not matter as the noise level from the DAC is so low to begin with.

Michael

 

[mctron]

The released format is less than half what the original studio master was. Down converting is at the very end of the process, for good reasons. So yes it is "mastering" but it seems very plausible to me that in many case, not all, that down conversion would create artefacts especially if the CD master is a decade old or more. In theory, the Redbook standard may be all we need, but theory and practice is different. You are doing mathematical operations to reduce the size of what was the "original" master. It may have been done with no artefacts, but it really likely have been done with a process that does especially if it have been done more than a few years ago. The High Res tech may not be superior today, but if you are listening CD quality, you are listening to a processed version, not the original, and you don't know exactly how good this process was.

Well,

If you want to make a point about 24/44.1 not being good enough and distinguishable from say 24/192 you must use a 24/192 recording, down-sample it to 24/44.1 (with a known good re-sampler) and post an ABX showing you can pass this test.

 

[PeteL]

Well,

If you want to make a point about 24/44.1 not being good enough and distinguishable from say 24/192 you must use a 24/192 recording, down-sample it to 24/44.1 (with a known good re-sampler) and post an ABX showing you can pass this test.

That's exactly my point.

 

[Trell]

If you want to make a point about 24/44.1 not being good enough and distinguishable from say 24/192 you must use a 24/192 recording, down-sample it to 24/44.1 (with a known good re-sampler) and post an ABX showing you can pass this test.

That's exactly my point.

No one argued that a bad re-sampler could not introduce audible artifacts, which is why one should use one of very good quality. The assumption is that those doing the re-sampling knows what they are doing, and this is what you should use in your own ABX.

 

[PeteL]

No one argued that a bad re-sampler could not introduce audible artifacts, which is why one should use one of very good quality. The assumption is that those doing the re-sampling knows what they are doing, and this is what you should use in your own ABX.

My point that resampler may not have been as good as they are now 20 years ago. and that may be a reason that in some case the "CD" masters of these era may not sound as good as the High Res masters. I am in agreement that We don't need more than 44/16, what I am putting forward is the argument than "if it sounds different it's about the mastering, not the technology" But mastering IS about technology. Don't you think that it's possible the down converting process may have improved in the last 30 years?

 

[morillon]

Oui j'en ai parlé dans un post précédent. Le 9039pro est sorti en mai, mais le SU-9 pro est le premier DAC que j'ai vu le proposer. Ils publient SINAD de 127, qui, sur la base des messages précédents d'Amir, semble dépasser les limites de l'équipement de mesure actuel si je le comprends correctement.

Heureusement, SMSL semble désireux de soumettre son équipement ici pour examen, alors j'espère que nous le verrons bientôt mis à l'épreuve, car l'appareil surpasse celui-ci, ainsi que le d90SE et le X18, en termes de prix. Moins de 500 $ !

Measurements of SMSL SU9 Pro ESS9039Pro DAC - L7Audiolab

台式设备 今年五月份（2022年5月）的时候ESS发布了9038Pro芯片的下一代（？）产品，ESS9039Pro。当时有过一阵子讨论，从编号来看9039Pro更像是9038Pro的"小改"，双目三林这次给我们抢先带来了 SMSL SU9 Pro 这款基于9039Pro芯片的产品

www.l7audiolab.com

 

[Trell]

My point that resampler may not have been as good as they are now 20 years ago. and that may be a reason that in some case the "CD" masters of these era may not sound as good as the High Res masters. I am in agreement that We don't need more than 44/16, what I am putting forward is the argument than "if it sounds different it's about the mastering, not the technology" But mastering IS about technology. Don't you think that it's possible the down converting process may have improved in the last 30 years?

Perhaps those in the industry can tell how much technology such as re-sampling has improved over the last 20-30 years, and how audible it is.

It would be interesting to see a comparison of a CD release of that era with the same master in original resolution and sample rate. Assuming that the master is high resolution to begin with, and I don’t believe that 24 bits/192kHz was commonly used that time or even available in general.

 

[PeteL]

Perhaps those in the industry can tell how much technology such as re-sampling has improved over the last 20-30 years, and how audible it is.

It would be interesting to see a comparison of a CD release of that era with the same master in original resolution and sample rate. Assuming that the master is high resolution to begin with, and I don’t believe that 192kHz was commonly used that time, if it even was available.

24 bits was the standard from the Get go and it didn't take long for higher sample rate to become standard too. It's just a guess, but I think that those who claim to hear a difference (which I don't until I test blind) are talking about older recordings. I don't buy into the whole industry conspiration scheme which some contributors try to push that labels would release compromised masters in standard resolution just to sell more high res. High Res is extremely niche. Labels want to sell music that sounds good. That's all I am saying.

 

[HDavidson]

Tous les sites semblent dire 9038 Pro pour le SU-10... semble que ce soit le SU-9 Pro qui a le 9039;

Toutes les annonces indiquent 2x ES9039MPro. Sur la photo, nous voyons un ES9039MPro.

SMSL SU-9 PRO DAC ES9039MPro XMOS XU316 Bluetooth 5.0 aptX-HD LDAC 32bit 768kHz DSD512 MQA MQA-CD - Audiophonics

Updated version of the SU-9, the SMSL SU-9 Pro takes the technical base of its predecessor while proceeding to an improvement of the integrated components in order to increase the performances with in particular the new DAC ESS ES9039MPro.

www.audiophonics.fr

 

[Trell]

recordings. I don't buy into the whole industry conspiration scheme which some contributors try to push that labels would release disputable master in standard resolution just to sell more high res. High Res is extremely niche. Labels want to sell music that sounds good. That's all I am saying

I’ve over 140 SACD myself, and almost all of them are multichannel. It’s the multichannel part that so very much improves the sound quality and I take that at 16/44.1 any day over a stereo 24/192.

 

[MCH]

View attachment 239156

Great explanation Michael, I remember learning all this from you some time ago in a different thread.
I wonder if in your last graph (pasted here above) wouldn't be 20 and 5 microvolts instead of 200 and 50.
Sorry for the confusion if my mental calculator is wrong
Edit: Sorry, I guess the graph shows the amplified noise. All good. How can I dare to correct the Master

 

[JSmith]

Toutes les annonces indiquent 2x ES9039MPro. Sur la photo, nous voyons un ES9039MPro. Translated: All listings state 2x ES9039MPro. In the photo we see an ES9039MPro.

Yes... for the SU-9 Pro, not the SU-10 which this review thread is about. There isn't an SU-9 Pro test/review thread here... yet. I hope that's as clear as mud now.


JSmith

 

[srkbear]

Measurements of SMSL SU9 Pro ESS9039Pro DAC - L7Audiolab

台式设备 今年五月份（2022年5月）的时候ESS发布了9038Pro芯片的下一代（？）产品，ESS9039Pro。当时有过一阵子讨论，从编号来看9039Pro更像是9038Pro的"小改"，双目三林这次给我们抢先带来了 SMSL SU9 Pro 这款基于9039Pro芯片的产品

www.l7audiolab.com

Interesting, thanks! SINAD of 123 here diverges from the manufacturer’s claim. Let’s see what Amir comes up with.

This one is the first that has tempted me in awhile, given that price and the jettison of another superfluous IIS and AES connector that I’ll never use. My primary interest is this new SU-9 Pro’s output voltage, as I’m quite happy with the output on my d90SE and wouldn’t want to go less. Looks like on your link the voltage is user adjustable from 4 to 5, with the 5 volt setting showing 5.246 volts, and I believe Amir measured the Topping at 5.1. We’ll see!

 

[Robbo99999]

I’m in agreement with your posts as a rule, but I’m not sure I think everything beyond 44.1/16 is snake oil—that seems a bit extreme in the dogmatic sense, dontcha think?

No doubt it’s arguable whether the vast majority of folks can hear the difference between Red Book and hi res audio, but that doesn’t mean that no one can, or that DAC manufacturers and streaming services are ripping us off by offering higher sampling rates. If that were true then the whole principle of reviewing DACs on here would be fraudulent above 96db!

I was slightly wrong in what I wrote, as I use 48kHz for gaming & internet and 44kHz for music, and all at 32bit just so that I don't lose any theoretical dynamic range when digitally lowering volume as part of a negative preamp to cover EQ boosts......so I should have said anything above 48kHz/32bit & 44kHz/32bit is "snake oil" in terms of DAC settings (unless you're producing music then I understand that higher sample rates during the music creation process can be beneficial as it goes through various stages of processing on it's way to the final product).....albeit I could probably shorten that to the 24bit version, but since my DACS can do 32bit I just set them to that. Maybe it was extreme to say "snake oil", but I don't think there is any audible benefit to high res music - Amir did a review on it one time, and there was just a bunch of noise above 22kHz.....I mean I don't know if all High Res music just has a bunch of noise up there, but you can't hear up there anyway, so hence me saying "snake oil" when it comes to High Res music, maybe that's unnecessarily extreme in wording, but it doesn't really matter, High Res music is an empty gimmick.

EDIT: the theoretical benefit of high SINAD DACS is that when you use digital volume control for whatever reasons, then you're able to retain a higher SINAD for X amount of digital volume attenuation vs DACS with lower SINAD, so you could still make some kind of a theoretical argument for DACS above 96dB SINAD even when listening to 44kHz/16bit audio files.

 

[staticV3]

SINAD of 123 here diverges from the manufacturer’s claim.

??


Wolf's measurements match SMSL's specs exactly

 

[pseudoid]

I hate to make a comparison because cars are NOT audio hardware, but... I must << RE: 16bit/96dB is satisfactory enough:
If you are a law-abiding citizen and never drive above the posted speed limits, do you really even need a speedo that goes above 75MPH ... let alone an engine/motor that delivers anything more than 60 horsepower???

 

[Jimster480]

I hate to make a comparison because cars are NOT audio hardware, but... I must << RE: 16bit/96dB is satisfactory enough:
If you are a law-abiding citizen and never drive above the posted speed limits, do you really even need a speedo that goes above 75MPH ... let alone an engine/motor that delivers anything more than 60 horsepower???

No sir you don't but as a "car enthusiast" I definitely need quite a bit more

 

[pseudoid]

No sir you don't but as a "car enthusiast" I definitely need quite a bit more

Sir Jimsky480, but you forgot to state what you'd do if you are an "audio enthusiast"!
No need to reply, if you agree my comparison (of cars v. audio) is relevant...
Personally, I sometimes believe my 400+HP sled needs more oomph... although I never exceed the speed limit, when I sense trouble ahead!