SMSL SU-8s DAC

Gear that comes in limited sizes has often been touted. And today, this is true with the SMSL SU-8s with impressive features in their small stature of 7.3 x 6 x 1.5” (187.5 x 154 x 40mm). We will dive deep into this small package to learn more about the SMSL SU-8s.

Build

The SMSL SU-8s DAC is a rather compact system that is at home in almost all setups. The following are the general specs of the SMSL SU-8s:

·        ESS ES9068AS DAC chip

·        DSD512 support

·        PCM 32bit/768kHz

·        Qualcomm aptX Bluetooth supports aptX, aptX HD, SBC, AAC

·        XMOS 16 core processor

·        Full MQA support

·        Three inputs: USB, optical, coax, Bluetooth

·        Two outputs: RCA, XLR

·        All audio inputs support DSD

·        CNC aluminum alloy shell

·        Tempered glass display panel

·        Bluetooth 5.0

·        Full function remote

·        Inputs: USB, coax, optical, Bluetooth

·        Outputs: RCA, XLR

·        THD+N: 0.00009% (-121dB)

·        Dynamic range

·        XLR: 126dB

·        RCA: 125dB

·        SNR: 126dB

·        Output impedance: <10Ω

·        USB transmission: Asynchronization

·        USB compatibility: Windows 7/8/8.1/10, Max OSX, Linux

·        Bit depth

·        USB 1bit, 16-32bit

·        Optical/coaxial 1bit, 16-24bit

·        Sampling rate

·        USB: PCM 44.1 - 768kHz, DSD 2.8224 - 22.5792MHz

·        Optical/coax: PCM 44.1 - 192kHz, DSD64(DoP)

·        Bluetooth version: 5.0

·        Supported Bluetooth codecs: aptX, aptX HD, SBC, AAC

·        Power consumption: 5W

·        Standby power: 0.5W

·        Size: 7.3 x 6 x 1.5” (187.5 x 154 x 40mm)

·        Weight: 1.74lbs (0.79kg)

The entirety of the features fit in this small box from SMSL with ample room to include Bluetooth 5.0, Optical, Coax, and USB inputs. For outputs, there are RCA, Bluetooth, USB, and XLR. We tried the Bluetooth and USB inputs and the USB and RCA outputs for creation evaluation.

We will be using the 64 Audio U6T IEM earphones, an SPL Phonitor SE Headphone Amp, and an iBasso DX240 DAP in addition to the SMSL SU-8s in this review.

Before using the DAC, we must select the correct input by using the “Input” button on the remote.  One item to note here is that you must press the “C” button, or the remote will not function – this is something we learned on our own.

Next, we used the USB of a Windows 10 computer running Roon to connect the SU-8s. The DAC showed up automatically on the initial connection to the computer. Afterward, we needed to setup the DAC in Roon by turning it on. This is not a problem if you are familiar with Roon.

For our amplifier on our computer, we used the SPL Phonitor SE headphone amplifier. The connection between the computer and amplifier was an RCA cable. We also used the same amp for Bluetooth mode. The Bluetooth pair was a bit more complicated. We enter the pairing mode as usual for Bluetooth, since the DX240 runs Android. Following the prompts will have you connected to the SU-8s. The SU-8s supports APTX HD, a higher bit rate of Bluetooth, which we will explain in the evaluation.

Evaluation

The SMSL SU-8s APTX implementation is quite good as I used Qobuz with the iBasso DX 240. The test track used was Tears for Fears “Woman in Chains,” from “The Seeds of Love” album. While this sounds fantastic for Bluetooth, there was just something missing. It was just a bit “soft” and lacked the exact impact of being over USB.

We switched over to the USB connection, where we can release the full potential of the SMSL SU-8s.

What can we say, “Darker Than Blue” from Courtney Pine is quite a challenging track for most devices to deliver appropriately, but the SU-8 can do so. For example, the saxophone is simply beautiful, right on the edge of breakup at its peak but not breaking up at all. Pine's voice is crisp, and the added baritone of the other voice in the track is crystal clear.

We did not use MQA, but the SMSL SU-8s supports encoding and decoding of MQA.

One added feature of the DAC that we find very attractive is the medium size display which shows a variety of information from the volume, input, and the Bit Rate of the current track.  In addition, the remote is straightforward once you become accustomed to the layout.

I will not bore you with the remote details as you can learn more by visiting pages 19 of 28 in the manual located here:

https://drive.google.com/file/d/1ztZO9lV5vjnIkQ3NeEPG8GcuoIiC1pZh/edit

Suggestion

Sure, the SMSL SU-8s do not just roll off the tongue, but it has quite a few outstanding points and some downfalls.

 Let us address the design - while pleasant on the surface, and one question comes to our mind...why are there only three feet? This makes it awkward to connect cables because if there should be any weight on the device, the SU-8s are apt to tilt in that direction. Included are four peel and stick feet. Unfortunately, we do not see this as a solution to the issue.

One other item – and this one is a little knit picky – is that we would like to see a slightly more premium remote included. To us, the one included felt relatively inexpensive.

Conclusion

Overall, the SMSL SU-8s is quite a nice, considerable DAC for under $400 (priced at $359.99) which features full MQA decoding and encoding, APTX, and balanced outs.  Pairing via Bluetooth is quite easy and has APTX. With a sound signature that is not analytical and easy to listen with some minor quirks, we can recommend the SMSL SU-8s!

To learn more information about or to make a purchase of the SMSL SU-8s, please visit the following link:
SU-8s-DAC

Gear Used

·        64 Audio U6T

·        SPL Phonitor SE

·        iBasso DX240

·        Window 10 PC

·        Roon Nucleus+

Music Used

·        Tears For Fears - “The Seeds of Love”
https://open.qobuz.com/album/jvkqqdbvb73yb

·        Courtney Pine - “Black Notes from the Deep”
https://open.qobuz.com/album/m1ntuo3eqehwb