The SMSL D6S review sample was kindly provided free of charge. I didn’t receive monetary or any other kind of compensation and I don’t use affiliate links. The price of the SMSL D6S is $199.99 but it is currently discounted at $169.99. Order yours from Shenzhen Audio .
SMSL D6S
SMSL is a well known audio brand from China that specializes in designing amplifiers, headphone amplifiers and DACs. They are very fast and among the first brands in the audio industry to utilize the newest DAC chips in their products.
Such a product is the SMSL D6S, a standalone DAC that features one piece of the brand new ESS ES9039Q2M DAC chip, which is an updated version of the venerable ES9038Q2M that is found inside hundreds of DACs around the world.
This newest version of the DAC chip employs the upgraded HyperStream IV architecture, instead of HyperStream II, and also measures slightly better pushing DNR to 130dB and THD to -126dB.
The SMSL D6S uses four, high-end, OPA1612 op-amps in the analogue stage which is balanced and a brand new, third generation, XMOS XU-316 receiver which supports PCM up to 32 bit/768 Hz, DSD 512 and full MQA decoding.
The circuit also includes a separate audio clock and a built-in, low-noise, switching power supply with separate rails for the analogue and digital stages.
Connectivity
The SMSL D6S has three digital inputs (USB type-C, Coaxial and optical) and two analogue outputs (XLR and RCA). The unit also supports wireless Bluetooth connectivity with the aptX HD and LDAC, high resolution codecs.
Design and build quality
Brand new is the design of the SMSL D6S which now looks more modern and contemporary than previous generation products that resembled industrial, studio gear. The new design element is a rectangular panel which contains the LCD display and stands out from the main chassis, adding a unique appearance to the device. Build quality is excellent, the full aluminum chassis is well made and finished.
Operation
You can control the device with the multifunction knob or the included remote control. The analogue output signal is variable and can be set from 0 to 99 for the full scale which is 2.5Vrms for the RCA and 5Vrms for the XLR outputs so you can drive all sorts of power amplifiers and active monitors.
You can also select the digital input or Bluetooth reception, adjust the LCD display brightness, select digital filter and DPLL level. During playback the only thing displayed in the LCD screen is the input sampling rate.
Accessories
The unit ships together with the remote control, a power cord, the Bluetooth antenna and a brief manual.
Associated gear
I have tested the SMSL D6S with the DROP + SMSL HO150X, Aune S17 Pro and Violectric V222 headphone amplifiers using the Focal Clear Mg, iBasso SR3 and HIFIMAN Edition XS headphones. All headphone cables are made by Lavricables . As per usual practice the device was left playing music for about 80 hours before listening evaluation.
Listening impressions
The SMSL D6S is as neutral as possible with perfect linearity and transparency. This is a mirror-like DAC with top-class fidelity that will convert the input digital signals into analogue without any hint of coloration or intervention from its part. I don’t have scientific measuring equipment but judging from my listening tests I bet that the SMSL D6S must have class leading measurements.
The background is totally black and dead silent, the sound is crystal clear, like spring water, with deep detail retrieval and excellent definition from the bottom to the top of the frequency range. The overall sound temperature is just a little cool but not cold. This is a slightly analytical DAC with a lean and rather dry texture but is not clinical or sterile sounding.
The dynamic range is impressive, the bass is deep, very impactful and contrasted with excellent technicalities and an absolutely linear frequency response but also a little lean and dry. The mid-range is transparent and resolving without artificial timbre but not that colorful. There is plenty of energy on tap, the treble is airy and ethereal with a touch of extra brilliance and sharpness. The sound is neutral – bright and bold with rapid transients but not harsh, piercing or fatiguing.
Not surprisingly, the soundstage is wide, especially from the XLR output, spacious and open with pinpoint imaging. Don’t expect though much depth, massive size or imposing holography.
Needless to say that the class leading transparency and the achromatic character of the SMSL D6S make it ideal for studio production while it can be easily matched with all kinds of audio chains where it will act as not being there.
Bluetooth performance
Bluetooth connection is fast, reliable and stable within a 5-6 meter working distance. The sound quality is stellar and only suffers from typical Bluetooth problems like some lack of refinement and resolution, a bit harsher and more grainy treble and a touch of artificiality.
Compared to the previous generation
Comparing the SMSL D6S with previous generation SMSL DACs that featured the ES9038Q2M chip, like the SMSL DO100, I would be lying to suggest that there are any significant sonic differences.
The D6S has a bit of extra transparency and dynamic contrast, and is just slightly more clean and technically proficient. Other than that, the sound signature is pretty much identical so if you already own the SMSL DO100 or another ES9038Q2M DAC by SMSL then I don’t think that is worth upgrading. On the other hand if you are in a hunt for a new DAC, then yes go ahead and buy the new version because it is marginally better and features the latest DAC chip.
In the end
The SMSL D6S is a DAC with masterclass transparency and linearity for the price and improved dynamic range compared to the previous generations. If you are seeking for an achromatic DAC with stellar technicalities, absolutely neutral sound signature and plenty of connectivity options then you can’t go wrong with the SMSL D6S.
Copyright – Petros Laskis 2023.
+ Perfectly neutral and linear + Excellent transparency and fidelity + Crystal clear and achromatic + Great technicalities + Dead silent + Impressive dynamic range + Ideal for studio production + Full scale 5V XLR output + Adjustable line out + Remote control + Excellent build quality + Affordable - Lean and dry - Marginally bright and analytical - Not that different sounding from previous generations
I just received my copy of this DAC and after only a brief listening session using flac files via usb to the D-6S then out via balanced connection to a Monoprice THX 887 amp I would like to say my impressions are extremely close to yours.
I replaced a Topping E50 that went belly up while I was away for a week. Very disappointed, as I was quite pleased with the Topping, but I believe this SMSL is a worthy replacement. I’m one of the believers in the digital filters. I can find one that has the least impact on the music of choice and be content. The D-6S retains the user settings when powered off. The Topping doesn’t.
My biggest concern now is the users manual for the D-6S. I haven’t been able to locate one for download, nor can I find any mention of this unit on the SMSL website. The tiny little pamphlet included with the unit is at best a joke.
Sorry to get so involved with my reply, as I intend only to praise your spot on findings for this D-6S.
Thanks for your insight on this DAC.
Thank you very much for reading and sharing your impressions.
To be honest I was too lazy to read the printed manual and I searched for a download but I wasn’t able to spot one. It seems that they forgot to upload the manual. Most functions are easy to figure out but you need the manual for the digital filters.
Can this dac connected to Android phone?
Yes, it supports OTG function with most phones. As you may already know though, functionality is not guaranteed with all Android phones. It works like a charm with my Xiaomi Note 12 Pro.
I would like to inquire whether simultaneous XLR/RCA transmission is possible?
Yes it is. They are independent no fear of short circuit.
Buongiorno a tutti, ho provato a collegare un tablet android, entrata usb con l’entrata usb del d6s, funziona male, si sentono rumori di fondo ed è inascoltabile.
Good morning everyone, I tried to connect an android tablet, USB input with the USB input of the D6S, it works badly, you can hear background noise and it’s unlistenable.
Can anyone help me?
Hello, OTG function may not always work properly. It depends on the Android phone/tablet. Some of them don’t have good support for this function. It also depends on the quality of the tablet. Some of them are very noisy. As first measure you should try to do the connection with another USB cable. Keep Android volume at max. If it still doesn’t work you should try another phone or tablet.
Your review is spot on…dry and lean. The SU1 sounds more palpable, relaxed, and natural.
Haven’t tested the SU-1 but I guess that is due to the AKM DAC chip.
Hi Petro,
Excellent review, as always!
I have a newbie question for you…
My humble setup consists of a Wiim Pro streamer connected digitally to my Cambridge audio cxa61, using its ess es9010 dac chip.
I am thinking about upgrading to a dac like the smsl d6s or something else in this price range.
Do you believe that, there will be a significant improvement in audio quality?
Is it worth spending the extra €..?
Thanks in advance
Hello Fotis,
The DAC of the CXA61 is very entry level and the chip is outdated. Upgrading to a standalone DAC it will bring audio improvement. But my question is – Have you tried the analogue output of the Wiim Pro? You might find it better than the DAC in your amp.
I have, actually, but it didn’t sound as good as the cxa61 DAC.
Perhaps you are reffing to the Wiim Pro PLUS that uses the AKM AK4493 chip.
No , I was referring to the Wiim you have. Anyway, since you don’t like it and you prefer the DAC of the CXA61, I suggest that ideally you should listen and compare before buying anything. Theoretically the SMSL D6s should be better but you never know.