SMSL D-6 DAC Review

SMSL D-6 review featured

In today’s article, I’m reviewing the SMSL D-6 DAC. The D-6 features dual AK4493s DAC chips, multiple inputs, including Bluetooth and balanced TRS outputs. It supports up to 32bit/768kHz and DSD512. The price is $169.

Disclaimer: This sample was provided by Shenzhen Audio for an honest review. All observations and opinions here are my own based on my experience with the product.

SMSL D-6 DAC Review
The SMSL D-6 offers a whole lot of audio quality at a low price. It's the perfect device to be at the heart of a budget HiFi system.
Add your rating here!2 Votes
Uncoloured, transparent sound
Insightful and emotive
Balanced output
Remote control
Hi-Res Bluetooth input
Sharp corners on chassis
No headphone amplifier
Our Score


SMSL D-6 front panel


At 148.27.5×112.8mm (WxHxD), the D-6 is fairly diminutive in size. It has roughly the same dimensions as the iFi Zen series products or a small book. The chassis is CNC crafted from aluminium alloy and has a smooth matte finish. The corners are all sharp (not really a con but a pet peeve of mine) but the overall build quality is good.

There’s an OLED display and multi-function knob/button on the front panel. The display gives you the usual information such as volume and current sample rate but it also helps you to navigate through the options such as input selection and digital filter settings.

Around the back of the unit, things are a lot busier. Here we find (from left to right): AC in, Bluetooth antenna, USB In, optical input, coaxial input, RCA out and balanced TRS out.

SMSL D-6 rear i/o

Bluetooth Connectivity

The SMSL D-6 comes with Bluetooth 5.1 and supports SBC, AAC, aptX, aptX HD and LDAC. I’m surprised to see such good wireless connectivity on a budget DAC like this and it adds a lot of versatility to this little unit.

Internals & Output Power

The D-6 is built around dual AK4493s DAC chips with an impressive THD+N of -0.00011%. The included CK-03 clock module is carried over from SMSL’s high-end models and makes jitter levels of the optical and coaxial inputs as low as USB. In addition, the SMSL D-6 sports a built-in high-performance power system, similar to the one found in the SMSL SU-6.

When it comes to power output, the D-6 pushes 4.0 Vrms from the TRS output and 2.0 Vrms from the RCA out. As far as the dynamic range goes, D-6 manages 123dB from the balanced output.

D-6 with remote control


I hooked the D-6 up to the Yulong Aurora and Feliks Audio Echo via the Line out and tested a variety of headphones and IEMs. I also plugged into the Burson Funk and SMSL’s own DA-6 and did some testing with my NHT C3 speakers. Lastly, I connected my KALI Audio LP-8 monitors via the TRS balanced output.

The majority of my evaluation was done using USB input but I spent some time listening via Bluetooth (LDAC from my Sony NW ZX-300). As expected, the Bluetooth performance is excellent and surprisingly close to the wired audio quality.

There are 6 PCM filters to choose from as well as 4 sound quality adjustment function settings where you can customize/optimize the audio output. I stuck to the default settings of FL1 and SC1.

To my ears, the D-6 sounds transparent and uncoloured; exactly how it should according to the provided measurements and AKM’s promotional video. What I’m hearing is audio quality that is above and beyond what I would normally expect from a DAC at this price point.

Play a hi-res version of Daniel Cavanagh’s “The Exorcist”, and the D-6 will pull you in with its clear and uncoloured sound. I’m struck by the clarity of the piano and the clean yet rich sound of the sullen opening vocals. The acoustic guitar sounds airy and crisp and I’m struck by the power of the bass when the drums kick in (pardon the pun). The detail is excellent, as is the layering and instrument separation.

Listening to Native Construct’s “Mute”, the D-6 handles the complex passages with confidence. The DAC easily keeps pace as the dynamic track dips and dives through its various stages, from the orchestral crescendos to the chilled breakdowns and the metalcore ending.

Switching to Karnivool’s “New Day”, the texture in the electric guitars is tangible and gritty. The imaging and positioning of each instrument are precise and akin to what I would expect from more expensive DACs. The vocals are emotive and nuanced and the D-6 shows it has a solid grasp on rhythm here too, as the percussion drives the song through its assorted phases.

SMSL D-6 rear view


At this price point, it won’t be easy to find a DAC that’s as clear, nuanced or accomplished as the SMSL D-6. Given its low cost of entry, you might expect compromises in the sound or features but to dismiss the D-6 without hearing it would be a mistake. This is the real deal and an easy recommendation for anyone looking for an affordable balanced DAC to add to their system.

D-6 specifications

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1 year ago

The review is very descriptive regarding sonics. Would like to hear about soundstage width and depth. Only other thing I would like to hear more of, is how it compares to the more expensive units in the same system.
Great job.
Mark in GA

doug s.
doug s.
1 year ago

no headfone amp is an ADVANTAGE, not a disadvantage, imo. why include something many folks (likely MOST folks) interested in a quality lo-cost dac will have no use for, and don’t want to pay for? want a headfone amp? buy one! want a dac/headfone amp in one box? buy one, and spend more money, for more stuff in the box. those of us looking for a quality dac that don’t use headfones appreciate product such as this. i’ve recommended it to two friends looking for a good inexpensive dac.

Dave Smith
Dave Smith
1 year ago

Having listened to this DAC extensively for over a month on a wide range of music I would have to agree with David’s assessment in this review. This is a great little DAC and performs faultlessly, no specific driver required so is essentially plug and play.
Dave S

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