SMSL DO400 Review


In this review, we take a close look at the SMSL DO400, the fourth generation of the brand’s popular desktop DAC, selling for $499 USD.


Disclaimer: the SMSL DO400 was sent to us, free of charge, by Aoshida-audio in exchange for our honest opinion. You can check their website through this link directly.

About S.M.S.L

Since its inception in 2009, Foshan ShuangMuSanLin Technology Co., Ltd (also known as S.M.S.L) has become a powerhouse in the audiophile realm, offering an impressive line-up of affordable and high-quality products. In fact, nothing summarizes this better than the words of my colleague Yagiz: “If you don’t know SMSL, you need to get acquainted as soon as possible, because you’re missing out on a lot.” 

Covering every genre, from DAC, to power amplifiers and headphone amplifiers, the brand won countless awards, thanks to its excellent quality/price ratio. And if the SMSL AD18 is the perfect example – an all-time best-seller now available in its fourth generation – what really impressed me was the DO200 + HO200 combo.


A desktop DAC + headphone AMP, that became my benchmark for any <$1500 configuration (and above) thanks to their amazing performances, great versatility, and exceptional scalability. A combo that became my daily drive, paired with my KEF LS50 Wireless in RCA, and my Audeze LCD-X in Balanced XLR 4-Pin, which only worthy opponent – in my opinion – remains the Hifiman EF400.

And so, when Aoshida offered me to test their new SMSL DO400, advertised as the brand final offering, I jumped right in.

The DO/HO/AO Series

As usual, we’ll get a quick look at the SMSL/Aoshida product range. Not all of them, of course, but the most recent one.


The SMSL DO100 is a compact desktop DAC, packing a dual mono circuit driven by two ES9038Q2M chips and four OP1612 OpAmp for the pre-out. It’s a nimble device, that offers what SMSL do best: good performance at a low price, in a nice package.


I reviewed that one quite some time ago, and here’s a quote from this review:

“Sound quality is surprisingly good, build quality is exquisite, I/O is versatile, and the conception design makes it the perfect desk companion, whether if it’s for your computer, a DAP or any other digital source. Pair it with a good headphone amplifier, or a pair of solid powered-speaker, and you’ll get one of the best experiences you might ever get, in this price range.”

Full review available here: 


Designed to work in tandem with the DO100, the SMSL HO100 is a compact desktop headphone amplifier basically shoe-horning the HO200. WIth an ultra-low distortion precision feedback circuit, exquisite build and a low-noise power system, this amp delivers one of the cleanest render you could get in a sub-$300 bracket.


I reviewed it too, and here’s a quote:

“Tiny but mighty, the SMSL HO100 is a real killer for the price. For less than $150 US Dollars, it’s simply one of the best desktop AMP you could get at the moment, and one of the most powerful. Sound quality is outstanding, build quality is lofty, power is bottomless, and the conception design makes it the perfect desk companion, whether if paired with the SMSL DO100, another DAC, or even a DAP. Pair it with a clean DAC to enjoy the device at its fullest and get a Y-split power cable to make a desktop duo, powered by a sole cable: the perfect duo.”

Full review available here: 


The SMSL HO200 is a desktop headphone amplifier, packing a lot of power in an ultra-compact casing. If it looks a lot like the SH-9 and SU-9 above, the HO200 is allegedly supposed to replace the SH9, thanks to some improvements and a slightly sleeker design.

I tested this device a few months ago, so here is an excerpt of this review:

Let’s make it short: for the price, the SMSL HO200 is one, if not the best, solid-state headphone amplifiers you could get at the moment. Build quality is great, the sound is superb, I/O is complete and either as a headphone amplifier or a pre-amplifier, the device was just darn impressive.

Full review available here: 


The SMSL DO200 is a desktop DAC embedding a dual set of ESS Sabre ES9068AS, full MQA decoding, an extensive I/O, and a full set of features, it’s a K-I-L-L-E-R. As expected, it shares the same design as the SO200 (headphone amplifier) and the AO200 (integrated amplifier) allowing the final user to create a full setup, able to power both your headphones and your speakers.

I tested this device a few months ago, so here is an excerpt of this review:

Once again, SMSL delivers an excellent piece of gear and the DO200 is, first, a great DAC, second, the perfect addition to the HO200, to make a compact but powerful headphone listening station. Build quality and sound is good, I/O is complete, and either as a pure DAC or a DAC + pre-amplifier, the device was just impressive.

Full review available here:


Sitting right between the DO200 and DO400 (today’s review) the SMSL DO300EX is an upper version of the previous model, packing even more power and features than before. With an AKM AK4191+AK4499EX DAC, improved power and UI, that desktop DAC/AMP offers high-end performances, at just a fraction of TOTL usual prices.

My colleague Yagiz got one for review, and here’s a quote from his review:

“Wrapping up, the SMSL DO300EX is an impressive all-in-one DAC, PRE, and AMP that demands consideration from any audiophile looking for high-fidelity audio in a compact package and reasonable pricing. Its great design and excellent build, cutting-edge flagship DAC chip from AKM, and comprehensive input/output options represent a significant value proposition in the market. Its performance, matched with user-friendly controls and a versatile feature set, ensures it stands tall alongside competitors like the Topping DX5. “

Full review available here:

So now, let’s dive into the review and see what the new SMSL DO400 has to offer!

The review continues on Page two, after the click HERE or by using the jump below.

Page 1: About the brand

Page 2: Design & Build Quality, UI & Usage 

Page 3:UI & Usage 

Page 4: Specifications, Bundle

Page 5: Sound performances

4.6/5 - (106 votes)

A nerdy guy with a passion for audio and gadgets, he likes to combine his DAC and his swiss knife. Even after more than 10 years of experience, Nanotechnos still collects all gear he gets, even his first MPMAN MP3 player. He likes spreadsheets, technical specs and all this amazing(ly boring) numbers. But most of all, he loves music: electro, classical, dubstep, Debussy : the daily playlist.

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