SMSL DO100 Review (Stereo DAC)

[Steveysteve]

So it can be used as a pre amp, which is a standard feature for most new DACs these days. If you don't want to use that feature just set the volume to '100' and it'll be as pure as pure can be.

Are there any disadvantages to using a DAC as a preamp, as opposed to having a dedicated preamp?

 

[PyramidElectric]

Are there any disadvantages to using a DAC as a preamp, as opposed to having a dedicated preamp?

From what I understand this is a fairly complex debate, but basically comes down to how good the dedicated preamp is, and according to ESS their digital volume is better than all but the most 'exceptional' analogue controls: LINK

 

[PyramidElectric]

Did you buy direct from the company? It is not on Amazon US as of yet

I got it from Aoshida, I've only ever used them to buy this, but great service.

 

[amirm]

Why, on the earth, this pure DAC has the volume knob? Could you exclude it?

Because all of them should! Seriously, most people these days have one source of audio: digital. It makes no sense to have to buy a pre-amp just to change volumes. This is especially so since you get a digital volume control in the DAC chip itself which assures accurate channel balance. Combined with a remote control, this is a must have feature in my book for any DAC.

 

[Robbo99999]

I've been using the equivalent of Filter 6 (Fast Linear) on my SU-9n, where it similarly cuts at 24kHz instead of 22.05kHz. At 44.1kHz sampling, like most of my music, shouldn't that dramatically worsen performance by letting a lot of out of band noise through the filter?

The Topping E30's best sharp filter performs exactly the same as Filter #6 in this review, and the Topping E30 got a tremendous review here on ASR, so you should be good with that filter. I have the Topping E30, it's good!

 

[MaxBuck]

This looks like a good bet to replace (or maybe just back up, if it gets fixed) my D30Pro. (Still waiting on final feedback from Apos Audio on that one.)

 

[Spocko]

I should've waited to get this instead of the Topping D30 Pro for $400 - I was looking for a budget balanced DAC with coax digital input.

 

[BeerBear]

Suspect? The default ESS ones have always been override able or customizable AFAIK. Also both M2 and M5 show it. It's not a mistake..

The M4 does not, though.
Sure, they could be configured differently... but all those MOTUs are designed to be low latency devices and sacrificing that to get a sharper DA filter doesn't make much sense (although I don't have any exact values to work with, the latency penalty could be small enough).

 

[Chr1]

Are there any advantages to the D30Pro over this? Looking for a budget DAC with both RCA and balanced outs...

Don't like the fact that the display doesn't show volume tho
..

 

[Spocko]

Are there any advantages to the D30Pro over this? Looking for a budget DAC with both RCA and balanced outs...

Don't like the fact that the display doesn't show volume tho
..

It really comes down to usability - what's the durability of D30 Pro vs the DO100, or the feel of the volume knob, etc.

 

[Spocko]

This is a review and detailed measurements of the SMSL DO100 stereo balanced DAC with Bluetooth. It was sent to me by Aoshida Audio and costs US 239.
View attachment 208131

Sorry about the fuzzy front panel picture. It looks better in person. The rotary control makes it nice to adjust volume. Back panel is the usual affair but with USB-C connector instead of the usual Type B:

View attachment 208132

Nice that AC adapter is built into the unit so you don't have to worry about a dongle. The usual SMSL remote control is provided.

SMSL DO100 Measurements
Let's start with our usual dashboard using XLR balanced out:
View attachment 208133
This is superb performance especially at this price, landing the DO100 nicely in our top 20 list of best DACs ever measured:

View attachment 208134

RCA output is just slightly worse:
View attachment 208135

Same shows up in dynamic range:

View attachment 208136

Multitone test shows the extremely low distortion:
View attachment 208137

We are talking 15 dB lower than threshold of hearing folks!

IMD distortion is excellent with ever so slight hint of "ESS IMD Hump:"
View attachment 208138

Jitter performance is superb across all three inputs -- something we don't always see:
View attachment 208139

Linearity is textbook perfect of course:
View attachment 208140

Seven different filters are provided:

View attachment 208141


Using the default filter 1, we get incredibly good performance in our wideband distortion measurement:
View attachment 208142

Conclusions
This is a flawless performance from SMSL. Every test is aced, leaving no room for any complaint whatsoever. When you consider that this state of the art performance is offered at relatively low cost, it is quite an achievement. There is no excuse left to not opt for full transparency folks.

It is my pleasure to recommend the SMSL DO100.

---------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

@amirm is there a "direct DAC" mode for use with a pre/pro?

 

[MRC01]

Shouldn't Filter #6 be the best filter to use: described as "Linear Fast Roll-off" on their website: ...

Sorry, it was @MRC01 I was thinking of.

With the SMSL SU-6:

Filter 6 has the flattest passband response, but it doesn't fully attenuate by Nyquist, so it leaks some HF noise. However, having full attenuation by 24.1 kHz means any HF noise it leaks is > 20 kHz. It's possible that HF noise may cause passband distortion indirectly , if it causes IM distortion in a downstream component (like an amp). Yet unlikely.

The flattest filter that fully attenuates by Nyquist is filter #3. The trade-off is that it has some ripple (about 0.1 dB) and is down -1.5 dB @ 20 kHz.

That's the problem with 44.1 kHz sampling: the transition band is so narrow you won't find a "perfect" filter. Each has its tradeoffs, choose your poison. These are the 2 best filters to choose from. I use filter #6.

 

[manisandher]

That measurement looks suspect to me, I posted about it before.

So, you think Amir measured the UltraLite and M2 incorrectly, but the M4 correctly?

I strongly suspect that Amir's measurements for the UltraLite, M2 and M4 are all correct. For whatever reason, MOTU seem have gone with a 'slower' filter for the M4.

 

[threni]

That's the worse thing about my Topping DAC as well, I have the E30, the remote is good to have but you have to do gymnastics to point it at the right angle!

I've taken to putting a CD case at the side of the E30 so it reflects light onto the sensor. It's only a problem at like 75 degree angles though.

 

[formula 977]

Of course the numbers are 'incredibly good' because the entire top of the audible spectrum is chopped off, along with its harmonics.

Default filter 1 is circa -12dB down @ 20kHz according to your AP plots... Not sure when that became remotely HiFi. Like, not ever. Certainly not in the digital era, or the open reel era, or even the cassette era.

Filter 3 is clearly the one you should be using for tests.

The last D/A converter you reviewed had the best filter response you've ever measured (the Chord) and yet this thing is getting top marks with arguably one of the worst default filters I've ever seen. Go figure. Where is the consistency?


Hardly. The default filter response (you used for testing) is poor and you know it.

Right behind you John. Very seldom an explanation or reasoning why this happens.

 

[juliangst]

Because all of them should! Seriously, most people these days have one source of audio: digital. It makes no sense to have to buy a pre-amp just to change volumes. This is especially so since you get a digital volume control in the DAC chip itself which assures accurate channel balance. Combined with a remote control, this is a must have feature in my book for any DAC.

I've seen reviewers complaining about the sound quality when using the preamp fuctionality of SMSL and Topping DACs.
Those people claim that a good analog preamp leads to much better results.
Can you confirm this or is this just audio reviewer nonsense?

 

[Steveysteve]

I've seen reviewers complaining about the sound quality when using the preamp fuctionality of SMSL and Topping DACs.
Those people claim that a good analog preamp leads to much better results.
Can you confirm this or is this just audio reviewer nonsense?

Might a possible problem be the strength of the signal?

 

[MRC01]

I've seen reviewers complaining about the sound quality when using the preamp fuctionality of SMSL and Topping DACs.
Those people claim that a good analog preamp leads to much better results.
Can you confirm this or is this just audio reviewer nonsense?

SINAD and SNR are usually measured at full output. But nobody actually listens at that level, MUCH too loud. So the question is, how much does the SINAD and SNR drop as you turn down the volume? This varies depending on the design of the device. So it's possible that some device D1 having excellent measurements is not so excellent after you turn down the volume to usable levels. And some other device D2 having less excellent measurements may actually be better than D1 after turning it down to usable levels. Or some other device D3 is always excellent at all volume settings.

So there is some thread of truth or possibility to that claim. However, usually it is only a thread and mostly B.S. With the digital volume controls that these DACs have, the output noise level is constant so SNR should drop roughly 1:1 as you turn down the volume. So if it measures 120 dB at full output and you turn it down by 30 dB to reach a usable or normal volume level, you have 120 - 30 = 90 dB which is still great for a normal listening level.

With headphone amps, @amirm measures the SNR at 50 mV to show how much it drops from full output, and what you can expect for a "real world" SNR at normal listening levels. It would be nice to see this measurement with DACs having a volume control.

 

[JSmith]

Those people claim that a good analog preamp leads to much better results.

Well it depends on how the digital volume control is implemented... assuming SMSL use this function of the ESS DAC chip;

The Sabre DAC Digital Volume Control: Better than Analog?

The ESS Sabre DAC built-in volume control The volume control is done just before the oversampling filter on the digital data. It can be set to 0.5dB increments and in order to avoid clicking upon v…

hifiduino.wordpress.com

JSmith

 

[PeteL]

I can't tell if you're joking, but any complex waveform with a fundamental at 20 kHz will have it's first overtone way up at 40 kHz. Any tone above 10 kHz will only ever be captured as a fundamental (sine wave) with 44.1 kHz recording.

Not sure what you mean, your signal can be as complex has you want but if it has harmonics above 20 kHz nobody will ever hear them. A square wave at 16kHz will sound to you has a tone.