SMSL DO400 DAC & HP Amp Review

[Herbert Shooler]

How long untill we get a dac where you can dial up the 2h,to say-40db etc..will such technology kill off the use of tube? get the 2h but keep very low noise...etc

 

[aagstn]

Seems pretty solid but I have just had too many bugs with previous SMSL products that they would never acknowledge or fix. Company is a pass for me.

 

[welwynnick]

Not sure who at SMSL approved spending R&D $$$ on fake tube modes over a standard feature like peq.

They didn't.
The functionality is already there in the ESS ES9039 and other DACs.
They just change the THD_C2_0 through THD_C3_7 distortion correction values in registers 98 through 115.
It's in the ESS Product Datasheet.

 

[Nango]

Four (!!) different colours on that little display, serifs mingled with non-serifs, different sources on top of this, omg why is this not diminishing or does ruin the verdict no matter which sq it delivers?

 

[Tatteredmidnight]

Four (!!) different colours on that little display, serifs mingled with non-serifs, different sources on top of this, omg why is this not diminishing or does not ruin the verdict no matter which sq it delivers?

I actually think it may be 5 colors, seems like the “H” next to USB is purple, but it’s a little difficult to tell with the quality of the image.

 

[PristineSound]

sheet metal

It's finally happening. They are starting to cut cost. Topping will follow suit soon.

I know some will be extremely thrilled. But man, this is the day I dread, a race to the bottom of the barrel.

 

[Nango]

I actually think it may be 5 colors, seems like the “H” next to USB is purple, but it’s a little difficult to tell with the quality of the image.

Indeed, you are right, it's purple colour, they put 5 (!!!) different colours on it!!!

 

[PlasticDoc]

The specs of this new SMSL DO400 are too close to the otherwise very good SMSL D-6s, but at double the price.

From the SMSL D-6s review: "Distortion products are at -140 dB! Incredible. SINAD as a result is dominated by noise, and landing the D-6s in our top 20 chart of all DACs tested:"

From the SMSL DO400 review: "Distortion is incredibly low at -140 dB! Noise dominates SINAD as usual, and places DO400 easily in our top 20 DACs:

According to the strict definition of innovation as "something new that brings satisfaction and value," the new SMSL DO400 is not an innovative product. It is not clear what is the "job to done" of this DAC.

 

[Power Pop 23]

And let's not forget Sabaj.

That is correct; however, SMSL also manufactures devices for other entities—such as Aoshida and Shenzhenaudio—in addition to their own line.

I look forward to the day when select audio companies manufacture devices exclusive for an entity called Tested Audio dot com.

 

[Billy Budapest]

I think it's to counter objectivist comments about products having distortion that is TOO LOW and sounds cold and analytical, and steer slightly towards the warm and cosy sound of tubes with much more 2nd harmonic in particular.

I challenge anyone’s hearing to be able discern harmonics -140dB under the fundamental or under 1% THD. It’s a horse $#!+ argument.

 

[1066]

Is there PEQ?

 

[shuppatsu]

Fine. Looks pretty nice, apart from the usual SMSL fontapalooza on the display. Measurements--meh. Bouncing off the AP's rev limiter like all the new measurements-oriented stuff these days. I like that they didn't skimp on power for the HPA, not that I'd need it. No PEQ, but aren't most of these HPAs connected to a desktop computer?

I'd prefer the DX5 II if I wasn't worried that it would blow up on me. But for me the DSP killer app is how RME can automatically detect which headphone you plug in and apply the correct profile, and apply loudness contours to boot!

 

[shuppatsu]

How long untill we get a dac where you can dial up the 2h,to say-40db etc..will such technology kill off the use of tube? get the 2h but keep very low noise...etc

There've been many products that simulate tube distortion over the years, and they don't stick around. The sound comes from the romance and the glowy things. I had a Carver amp 25 years ago; honestly by the time I switched the cables to the simulated tube outputs I forgot what the regular outputs sounded like. They both sounded fine.

 

[Cbdb2]

The two companies have been the earliest in the race so no wonder they are still on top. SMSL though, had been going sideways on a few products though. So good to see them back to their roots.

I would have found it interesting if you had listened to the distortion settings? You mentioned the Tube mode distortion is low and is probably inaudible but dosnt one of those distortion modes add another 25db of distortion above the tube mode? Rich 3 at 2 volts has sinad of 80, is that even audible?
If your going to offer variable distortion, make it obvious at the max setting.

 

[Gorgonzola]

View attachment 531081

SMSL are probably doing what Topping and Okto do with some their products, and use the ESS THD Compensation function. This is intended to minimise the distortion of the completed product, but these manufacturers appear to be offering the user the ability to increase 2H & 3H distortion. I think it's to counter objectivist comments about products having distortion that is TOO LOW and sounds cold and analytical, and steer slightly towards the warm and cosy sound of tubes with much more 2nd harmonic in particular.

View attachment 531084
Topping offer a fairly extreme Valve Mode in their Sound Simulation Function:

View attachment 531085

What Topping and SMSL are understanding is that what people actually like about tubes is low-order harmonic distortion, especially 2nd order -- and IMO, I don't think there is really a lot more to tube sound than that. How much more ideal it is that the this effect can be introduce more perfectly with solid-state design than actual tubes.

There is very little doubt that 2nd order harmonics are at worst benign and, for many people, warmer and more "musical" experience than a distortionless design. IMO, 2nd/3rd also mask other distortions i.e. higher-order harmonics.

BTW, I still enjoy my tube preamp from time to time.

 

[Eulipian]

This is a review and detailed measurements of the SMSL DO400 DAC and balanced headphone amplifier. It was sent to me by Aoshida Audio and costs US$499.
View attachment 531050
It is not quite visible but there are contours on top of the front panel sheet metal, giving the DO400 a higher end look. I expected the user interface to be revamped as well but it is standard SMSL UI. It is easy to use though so not a practical issue.

Back panel shows the usual connections:
View attachment 531051
I wish there was trigger out support though. And some would like HDMI ARC instead of I^2S.

Instead of running my usual measurements, I omitted a few and added a bit of others.

For these measurements I decided to upgrade to the latest version of Audio Precision software which finally supports WASAPI audio instead of having to use ASIO emulation. Was so happy to see this. I connect to the SMSL and I am shocked to see lots of distortion. SINAD was a poor 95 dB! I hunt around, change things, read the manual over and over again and still can't figure out why there is so much distortion. Frustrated, I switched back to ASIO and same problem persisted!!! I then remembered the so called sound color setting. Look in there and it is set to "Rich1" instead of "standard!" Switched it to standard and everything was well. I hope SMSL changes the default to standard. As otherwise, you have paid a lot of money for a product that underperforms a dongle when it comes to distortion....

SMSL DO400 Measurements
I started with volume set to 0 dB and XLR output:
View attachment 531052
Distortion is incredibly low at -140 dB! Noise dominates SINAD as usual, and places DO400 easily in our top 20 DACs:
View attachment 531053

RCA output costs you a bit but not much:
View attachment 531054

Since I was on topic of sound color, I decided to measure the impact of various settings:
View attachment 531056

As you see, it costs fair bit in performance. Strangely, "tube" mode is the same as Rich 1, at least in total THD.

I dug in more into tube mode:
View attachment 531057
It does push second harmonic but nowhere near what a real tube product would do. I doubt very much typical person can hear its impact.

Back to noise, performance is superb:
View attachment 531055

Jitter is absolutely clean with USB:
View attachment 531058

As is Multitone:
View attachment 531059

I didn't check which filter was active for our wideband test:
View attachment 531060

Next, I measured balanced headphone out. I found it super clean in low gain mode with plenty of power:
View attachment 531061
View attachment 531062
As you can see, in high gain with 32 ohm, it really smokes! That should be plenty to drive any headphone to any loudness level.

There is no negative, low gain mode so in this department, the DO400 turns in middling score:
View attachment 531063
So very sensitive IEMs may not be a good fit.

Conclusions
SMSL turns in some of their best engineering in the DO400. DAC performance is state of the art. And headphone output is very clean in low gain mode and very powerful in high gain mode. We could use a couple of other features and a very low gain mode for IEMs. But that is it.

Price is reasonable for this class of product and I like the new front panel.

I am going to recommend the SMSL DO400.
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As always, questions, comments, recommendations, etc. are welcome.

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Wonder if SMSL will go upscale at some point and produce something to compete with Eversolo or MiniDSP, or if they're happy being among the top cats of the desktop market?

 

[sailor2005]

A "coloured" factory default setting is a no-go for me. Probably many won't know.
Hope such "brilliant ideas" will not spread.
And no PEQ...

When I got mine back in 2023, it was set to standard by default and not one of the colored options. I don't remember many DACs with PEQ being available at that time, except the RME ADI-2 ( I have one too) and it was 2x the price of the SMSL. So you have to consider that this DAC came out in 2023.

 

[respice finem]

When I got mine back in 2023, it was set to standard by default and not one of the colored options. I don't remember many DACs with PEQ being available at that time, except the RME ADI-2 ( I have one too) and it was 2x the price of the SMSL. So you have to consider that this DAC came out in 2023.

Oh, thanks, I thought it was new, must have misread it.

 

[Billy Budapest]

What Topping and SMSL are understanding is that what people actually like about tubes is low-order harmonic distortion, especially 2nd order -- and IMO, I don't think there is really a lot more to tube sound than that. How much more ideal it is that the this effect can be introduce more perfectly with solid-state design than actual tubes.

There is very little doubt that 2nd order harmonics are at worst benign and, for many people, warmer and more "musical" experience than a distortionless design. IMO, 2nd/3rd also mask other distortions i.e. higher-order harmonics.

BTW, I still enjoy my tube preamp from time to time.

I contend that “low order” harmonic distortion created by many tube amp circuits is not audible. What people are hearing instead is the roll-off at both high and low frequency extremes (i.e., “warmth”) and the low damping factor (i.e., “tubby bass”). Distortion has almost next to nothing to do with “tube sound” unless the distortion is so extreme that the harmonics are something like 50dB below the fundamental or the THD is exceeding 20%.

 

[Rick63]

Well look at that, 16 of the top 20 highest measured SINAD DACs are either Topping or SMSL.

Quoting myself here.

While it's nice that it measures well and all, it's easy to see why Topping and SMSL have almost all of the top 20 measuring DACs. It's because they both seem to release a new model every other month. Most of the time all they appear to be doing for the most part is chasing a little more SINAD and changing the casework.

Here's what I'd rather see them do:

1. Stop racing to compete with each other in the SINAD race, as anything above their current numbers would be completely inaudible to the human ear.
2. Add more features that folks have been asking for such as EQ, HDMI eARC, and perhaps an AES input.
3. Focus a more on RELIABILITY!!

Number 3 should actually be number one. I mean, what good is it to have SOTA measuring DACS when so many folks continue to have reliability issues with these products? And IMO it is ridiculous to have to continuously update the software to fix bugs that shouldn't have been there in the first place. I get it that those companies are in business to make money but come on man!!

This is coming from someone who owns a Topping D70 Pro Sabre & SMSL PL200T transport that I love. The thing is that long term reliability concerns are always on my mind. I can see why there are folks here are willing to pay more for reliability and peace of mind while sacrificing a little bit in measurements. Not to mention adequate customer support!

Color me frustrated...


Edit: Based on some of the posts in this thread I assumed this was a new release. I now see it is a nearly 3 year old unit. Some of my earlier comments were based on the fact that I thought it was recently released so I somewhat take some of the criticism back. However I stand by what I said earlier about giving their customers what they want in terms of new features (though they mostly do pretty good at this already), and mostly reliability and customer support.