SMSL DO300 is a high-performance DAC built around the new flagship ES9039MSPRO chip. It offers a great functionality, and it's priced at $549.


We’ve reviewed quite a few SMSL products in the past here at Ear Fidelity, and now it’s time for their newest DAC, the DO300. Even though you must have lived under a rock for the past 5 years not to have heard about SMSL, I’ll give you a quick introduction regardless.

SMSL is a Chinese company that specializes in manufacturing audio equipment. The company was founded in 2009 and its headquarter is located in Shenzhen, China. They are widely regarded as one of the two leading DAC and amplifier manufacturers in the audio world currently, next to Topping. They are known for producing a wide range of audio equipment, including DACs (digital-to-analog converters), headphone amplifiers, preamplifiers, power amplifiers, and speakers. The company’s products are highly regarded for their exceptional sound quality, reliability, and affordability. They also constantly push the limits when it comes to measurements of audio equipment, being arguably the best measuring audio gear manufacturer in the world.

Today we’re taking a look at their newest DO300 DAC, which is built on the newest ES9039MSPRO chip. 


When it comes to the unboxing experience of a SMSL product, everything has been written already a lot of times. This is an innovative and very competitive company, but when it comes to the presentation, it is definitely function before form. The DO300 is no different, since it comes in a standard white box, that only included things that are essential and functional.

So, inside the packaging, you’ll find a power chord, a USB cable, remote control, and a Bluetooth antenna. Nothing fancy, we’re all used to what SMSL brings to the table, and it’s definitely not exquisite attention to the unboxing experience or providing luxurious accessories. At the end of the day, this is a very high-performing DAC, there’s nothing that you should be expecting to be included at this price having the level of performance in mind.

Design and Build Quality

Speaking about the build quality and design, I could say exactly the same as in the unboxing paragraph. Most of SMSL’s products look similar and the DO300 is the same story here. It’s built well, the finishing is alright, and there’s nothing really to write a book about. On the front, you’ll see a volume knob and a screen, and at the back is where all the inputs and outputs are located…logically.

Regarding the overall design and build quality…you can relate to our DO200 review, as these two devices are just identical apart from the model number on the front. The dimensions, the weight, and the design are all perfectly the same between the two devices. I’m not saying it’s a bad thing at all, it’s cheaper for SMSL to utilize the same chassis to cut costs, resulting in you being able to buy the new DO300 cheaper. Being green is cool.

Tech and I/O

Now onto way more interesting stuff. First of all, the DO300 is the first device I know to use the brand-new, flagship ES9039MSPRO chip. It has built-in MQA support with MQA-CD, but to use the latter, your cd has to support MQA output. It also has the newest XMOS XU-316, which is its 3rd generation, supporting PCM up to 32bit/768kHz, DSD, and DSD512. 

The DO300 also uses the new self-developed CK-03 clock processing circuit which greatly reduces clock jitter, and a Qualcomm QCC5125 Bluetooth chip with LDAC support.

All that makes for a DAC that is more than suitable for current needs and market standards. SMSL has been offering technically impressive stuff for many years now, and they’re not stopping that anytime soon.

As far as I/O goes, you’ve also got everything you could need. RCA and XLR outputs, AES/EBU, I2s, coaxial, optical, and USB inputs. Sadly, no USB-C this time, and it’s about time for it to be a golden standard in our hobby. Apart from that slight inconvenience, the DO300 is a highly functional device that will make you connect basically everything you’d want. Oh, and a Bluetooth antenna if you want to use it wirelessly.


We’ve done many SMSL reviews, so we know what you’re really here for – the sound. Reviewing SMSL gear is getting harder and harder every single time we’re doing it, since all of their products sound very alike, with the difference being mostly in the actual quality (detail, resolution, etc). 

So, the DO300 is yet again another SMSL device with a very slight twist – it’s a bit warmer than most of their stuff in my opinion. No, the DO300 is NOT a warm-sounding DAC, but compared to their other models, it’s warm-ish.

The DO300 has everything you could expect from a SMSL DAC – incredible detail retrieval, fantastic resolution, speed, control, and spot-on tonality. Actually, because it’s slightly warmer than their other DACs, I like the DO300 the most out of everything else I tried.

Because of that slight tilt in tonality, the midrange gets buffed a little, especially in the note weight and timbre of male vocalists. While every single SMSL I’ve tried offers a very neutral and realistic color, the DO300 just gives you a little bit of that oomph in the midrange frequencies, which helps bring the vocalist a bit closer to you. This aspect is highly subjective though, as most SMSL fans are all about that ultimate neutrality and transparency. 

Don’t worry though, as the DO300 is still incredibly neutral and transparent. As I said, that touch of warmth is really subtle and it won’t break your experience if you’re a “neutral” guy. However, if you strive for absolute linearity, the DO200 might actually be a better choice for you.

When it comes to detail and resolution, however, this is performing incredibly well at its price range. I said it in the past already, but you really would have been paying 20x more for this kind of technical performance 10 years ago. It never gets old, this is so impressive yet so positive that it makes me sympathize with SMSL so much more.

As I’m used to with SMSL DACs, the bass is fast, perfectly controlled, and firm, it never bleeds into the midrange and it never gets boomy, even by the slightest margin. If you have some great performing headphones in the bass department, you’ll be blown away by what this little champ is capable of. The texture, rumble, attack, slam, and control are both on a very high level and I don’t think you will be able to find this kind of bass performance on a similar budget elsewhere.

The treble is also fantastic. Shimmering, sparkly, fast, and detailed, with a lot of air. It goes perfectly with well-mastered music, but as usual with SMSL – badly mastered music can sometimes be a pain to listen to. It is because the DO300 doesn’t hide anything from the listener, it just decodes all the information from the recording and sends it further, with absolutely no hesitation. There’s not even the slightest blanket, darkness, or dullness to the sound, this is highly saturated and just accurate.

Because of all of this, the DO300 is another fantastic DAC from SMSL. While being slightly different than the rest of the DO series (DO100, DO200) because of its slight warmth, it still performs beautifully and is insane when it comes to value.



As I said in the previous paragraphs, the main difference here is the slight warmth found in the DO300, while the DO200 is just ultimately neutral. This will define whether you’d like one or another. 

However, the DO300 has an upper hand when it comes to technical performance, but it’s again, very slight. I feel the DO300 has a bit better detail retrieval, even though the DO200 is basically surpassing most of the headphones in the market when it comes to what you’re able to actually hear.

As for the rest of the frequency response, these two DACs are very similar when it comes to both subjective and objective sound, which makes it easy for me – I can definitely recommend both, and the two things that you should consider while making the decision are price and slight tonality differences.


And now onto the comparison with the smallest brother, the DO100. Yet again, the DO300 is slightly warmer than the DO100, but in terms of technical performance, the latter is just not able to keep up.

The detail retrieval and resolution of the DO300 are audibly better, making for a more impressive listen. If you’re on a budget and you don’t have really high-end headphones, the DO100 will probably give you everything that you need. But if you’re looking for an upgrade, and your headphones can handle the actual difference, it really might be worth investing and getting the DO300 instead.

But, this comparison is not really fair is it? The DO300 is 2.5 times more expensive than the DO100, and it’s certainly not 2.5 times better. Audio is not about that though, so if you have the DO100 and you’re looking for something better but in a similar fashion, the DO100 might be the perfect upgrade for you.


The SMSL DO300 is everything that we’re used to from the Chinese manufacturer – incredibly clean, detailed, airy, and neutral. While slightly warmer than the rest of the DO series, it’s still very transparent and linear sounding. 

Apart from the impressive technical performance, this is a DAC that offers everything a modern DAC should offer – a vast selection of digital inputs, a balanced output, Bluetooth, and MQA (if you actually want to use it). This leads me to a very easy recommendation to everyone that is looking for a DAC on a $500 budget, as this might just be the best one you can choose.

Highly Recommended.

Big thanks to Aoshida-Audio for providing the SMSL DO300 for this review. I wasn’t paid or asked to say anything good or bad about this product, all of the above is just my personal, unbiased opinion. Aoshida-Audio hasn’t seen this review before publishing it. You can get the DO300 here.