SMSL DO300 – DAC With Added Warmth

SMSL DO300 front


Tested at $549

Sound quality











  • Pleasent sound signature
  • Smooth presentation
  • Very good value


  • Strong competition

SMSL DO300 is yet another variation of a midrange DAC coming from the brand. Given how good the previous SMSL was at this price point, and yes I’m talking about SU-9 Pro, I was curious to see if they could surpass it in such a short time. Let’s find out.

Build and Features

SMSL packed a lot of stuff into the DO300. Starting with digital inputs, we got all the usual suspects: USB, optical, and coaxial. Bluetooth is also on board and so is an I2S which is not that common at this price range. When it comes to the output section, we get both single-ended RCAs and balanced XLRs. Output can be set to either fixed or variable value levels.

The heart of the DAC consists of the flagship grade Sabre ES9039MSPro chip. The signal processor has been updated to the latest XMOS XU316 version and MQA is on board too if you care for it which I don’t believe you should at his point while the MQA organization is on flimsy feet. And that would be it, I don’t want to copy-paste every single technical detail from the manufacturer’s page. You can read all of it on the official product webpage for yourself if you wish. Here, I’ll be talking about what matters the most – the sound.

As usual, SMSL provides a rich user experience. DO300 has a small IPS display and a remote, and more importantly, it lets you tweak a lot of things. Among those are choosing a digital filter, using DSP to alter the sound color, changing DPLL (jitter suppression level), setting the display’s brightness, and even choosing the time after which it will automatically turn off. I got it set to only 5 seconds cause I like my displays dark unless I really need them. Anyways, this DAC’s UI is both rich and user-friendly – great job.


In line with SMSLs of late, DO300 sounds full-bodied and punchy. The bassline is weighty and voluminous, but not slow or sluggish by any means. There’s a respectable amount of agility there, punch too, and it really adds to the excitement in every song. Move up the frequency spectrum and the midbass is still very lush sounding, but masterfully tuned to add just the right amount of warmth and fullness to the midrange. This makes every vocal sound very lush and quite rich with timbre. Leading instruments that are prominent in the mix are handled the same way too. Leading guitars sound present, big, and simply lush. The piano is presently full too, while drums have all the mass and energy that I could wish for. High-frequency details are clean and crisp and definitely more prominent than they were on the previous DO200 MKII model. Still, they’re mature and don’t draw too much attention to themselves, letting the midbass and lower midrange lead the way in impressing you with their warm and full tuning. But all said and done, I feel that the tonality of the DO300 is slightly better balanced this time.

Move to the soundstaging and here we find a forward and dense sound character. Soundstage depth and the empty space around instruments are more than decent but not something that this DAC puts as its highest priority. This kind of full, tonally rich, and dense sound makes for a very easy listen.

Finally, if we talk about dynamics, this is not a flat-sounding DAC by any means. There’s lots of drive and punch to make this an engaging and bold listening experience.


SMSL SU-9 pro which I tested just before this one is its biggest opponent currently on the market. SU-9 Pro is an absolutely great DAC and I scored it appropriately. But here’s the thing, DO300 is quite great too. No matter how many times I compared them I couldn’t choose an outright winner here. SU-9 pro has a slightly more laid-back midrange, and because of that some vocals and instruments might appear more laid back in the soundstage too. Its bassline also feels a bit more neat and tidy. DO300 on the other hand has a more forward presentation with a fuller bassline and warmer midrange that appears closer to the listener, but less spatious. Everything else is comparable: dynamics, detail retrieval, good tone timbre, etc. Just think about that different tonality and soundstage presentation and choose your poison. I personally felt that the SU-9 Pro is a more neutral one, and since it’s more affordable too, I’ll give it a slight advantage in this duel. But if you really want that I2S output that only DO300 offers, feel free to choose it instead.

Topping E70 velvet is a DAC that is very close to both SU-9 Pro and DO300. Tonally speaking, it’s somewhere in between, slightly warmer than SU-9 but not as much as DO300. When it comes to the soundstaging, it is the same story again, not as laid back as SU-9 but not as forward as DO300. To cut a long story short here, I feel that E70 velvet is also slightly warmer than what I imagine to be perfectly neutral, but it’s closer to neutral while keeping all the other good traits that DO300 offers, like good tone timbre, dynamics, etc. It’s more affordable too and I had to take that into account when scoring them.


SMSL DO300 is a fine DAC on its own and a good value too. However, I can’t feel too hyped about it because it doesn’t really manage to surpass the SU-9 Pro that came before it at a slightly lower price. Still, this is a well-built and great-sounding product, and one of the sparse models that offers I2S connection at this price if that’s maybe something that plays a part in your buying decision.


DAC chip: ES9039MPRO
Format support: PCM up to 32 bit / 768 kHz, DSD up to DSD512
Inputs: USB, Optical, Coaxial, AES, I2S
Bluetooth: Apt-X, Apt-X HD, LDAC, UAT, SBC, AAC
DNR: XLR 134 dB, RCA 128 dB
Line out: RCA, XLR
Power supply: 110/220 V AC
Power Consumption: 10 W
Standby power: < 0.5 W
Size: 210 X 185 X 43 mm (WxDxH)
Weight: 1.2 kg

Official product page

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