SMSL D-6 Review

Controls & UI

There are two ways to control the D-6. The volume wheel and the remote control which is supplied with the unit. Of course, the volume wheel doesn’t offer the same level of control as the remote control.

It’s fairly easy to learn how to use the menus on the remote control. The menu is accessed by pressing the center button on the remote control. The product has 3 main modes, Pr1, Pr0, and Prd. PR1 indicates that the DAC is in preamplifier mode and the volume can be controlled in this mode. Pr0 indicates that the volume is fixed at maximum, which we call DAC mode. Prd is DSD pass-through mode. The D-6 comes with a total of 6 different digital DAC filter options. I used the default filter. As a rule, SMSL and Topping put the default filter setting in their equipment that they have found to be the most successful in their measurements, so in my experience so far I have not found that playing around with this setting makes any audible difference. Apart from this, the product also offers tone control. There are 4 different options here. You can also adjust the brightness of the screen within the 8-step range.

There are a couple of shortcuts on the remote. A dedicated mute button on the remote control allows you to quickly mute the unit. You can also control the volume of the DAC using the dedicated volume buttons and activate Bluetooth mode by pressing the FN button. Overall, the D-6 is quite straightforward to operate and one can learn to use it almost instantly out of the box.

DAC Performance

The SMSL D-6 uses a DAC chip called AKM’s 4493S, a revised and improved version of the old 4493. The D-6 uses two of these chips in dual configuration. I tested the product both with different amps and by directly connecting it to my active reference monitors and I will convey my findings. 

Firstly, straight from my Focal Alpha 80 monitors, the DAC sounds flat, surgical even. There seems to be no trace of the VELVETSOUND characteristics I am well accustomed to. It appears that SMSL did an interesting job with its implementation. The D-6 carries plenty of detail, whilst staying balanced across the spectrum. It is flat, accurate, and transparent. It reveals and highlights the flaws in poorly mastered tracks, which could be an issue depending on the equipment you plan to pair it with. I have an old Edifier R1280 and it is a warmer-sounding budget-oriented active speaker. Pairing it with the D-6 greatly enhances its technical performance, making its sound signature a little more neutral. That being said, I recommend paying extra attention to the synergy with the D-6.

Pairing the D-6 with Topping’s L30 II amplifier yields similar results. The amplifier also has a neutral sound signature similar to the D-6, and when you pair this combination with the Edition XS, you witness a match that outperforms its price in terms of technical performance.

Wireless Performance

Going wireless with the D-6 delivered a better result than what I expected. The QC5125 performs beautifully. The sound is very similar to what we get with wired, but there are a few nuances that are easily heard with the Alpha 80s but not so obvious with the budget-oriented Edifiers. In LDAC, resolution and upper treble performance are slightly negatively affected, but I wouldn’t say it’s a significant difference, especially if you are planning to use it with active speakers. This difference becomes much more pronounced when I listened to it using L30 II & my reference IEMs, Vision Ears VE7. The high treble feels slightly rolled off, in comparison to the wired mode. Also, the bass lost some definition as well. Yet, I find its performance very decent for a $169 USD DAC.

Comparison

vs. E30 II ($150 USD)

Entering the ring with similar specs down to the dual DACs, the E30 II is Topping’s first line of defense when it comes to DACs. It costs 150 USD and we praised it in our review from a while back. Sound-wise, they couldn’t be any more divergent. Here we see the importance of the implementation and other components rather than the DAC chips. The sound signature of the E30 II is a little more rounded than the D-6 and is not as surgical and analytical as the D-6. It features a slightly better bass impact and overall smoother upper midrange to high treble region. The D-6’s resolution and detail retrieval feels superior, especially with capable IEMs. The D-6 feels slightly more expansive but E30 II’s imaging and layering feel more natural in comparison. Both options are quite feasible, but there is an important feature difference between the two devices, which is the lack of Bluetooth connectivity option on the E30 II.

vs. FiiO K7 ($199 USD)

The sub-200 price bracket is a pit full of rivalry. Another great contender in this range is FiiO’s K7 DAC & AMP. Especially if you don’t need wireless connectivity. The K7 features the same DAC chips in the same dual config design. In addition to that, it also comes with an amp stage where FiiO used their THX collab creation, the THX 788+ amp modules. We especially liked its balanced performance and pitting it against the D-6 seemed like a prime idea to me. Firstly, if you’re only in the market for a source for your IEMs or headphones, opting for this will probably save you more than a hundred dollars as you won’t be spending extra on an amplifier to pair the D-6 with. 

In terms of sound, when I compared them side by side with my reference monitors, I found that the D-6 has a slightly more linear, slightly more analytical sound signature compared to the K7. The D-6’s stage is wider and sounds a bit airier. In addition, the K7 feels a bit more musical and dynamic and works well with many genres. In terms of resolution, the two devices are close. When I used both devices single-ended, I found that performance, especially technical capability, was negatively affected, so I recommend that you take this into account when deciding. The K7’s amp stage is just as satisfying in terms of performance as its DAC stage, so I would say that it is a better choice for headphones, but the lack of LDAC and the fact that it is a much bulkier device in terms of size are among its negatives.

Last Words

SMSL did a great job with the D-6. It is a feature-packed device with full-fledged LDAC support and a clean, resolving sound signature. Thanks to its compact chassis, it won’t take up much desk space, and its light weight means you can easily stick the D-6 to the side of your active speakers. The LDAC performance is impressive, especially for the price. 

The sub-$200 price bracket is a difficult one, but I believe that the D-6 can find a place in the market with its features and impressive performance compared to its price.

Pros

  • LDAC Performance
  • Clean and neutral signature
  • BAL Output
  • Compact Size

Cons

  • TRS is not widely adopted yet
  • Lackluster SE performance

 

Page 1: SMSL, SMSL D-6, Packaging & Accessories, Design & Build Quality, Bluetooth Capability

Page 2: Controls & UI, DAC Performance, Comparison, Last Words

4.5/5 - (285 votes)
Facebooktwitterredditpinterestlinkedin

Long time Tech Enthusiast, an ambitious petrol-head, Yagiz likes his gadgets and always finds new ways into the tinkerer's world. He tries to improve anything and everything he gets his hands onto. Loves an occasional shine on the rocks.

1 Comment

  • Reply October 26, 2023

    Jerry J.

    These DACs with AKM chips need burning in. It sounds cold and flat in the beginning. Needs 3 days, then you’re good and sound becomes excellent.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.