• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

SMSL SU-6 Review (Desktop DAC)

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
35,859
Likes
142,246
Location
Seattle Area
This is a review and detailed measurements of the SMSL SU-6 stereo Bluetooth and USB DAC. It was sent to me by the company to be sold by Shenzhenaudio. It will cost US$169.99.

I really like the slick look of SU-6 with its white LED:
SMSL SU-6 Review Bluetooth USB Stereo DAC Bluetooth.jpg

Yes, you can adjust the brightness level (I think there are four). The single touch button powers the unit and lets you cycle through inputs and settings. A remote control is provided to make that task easier. Back panel shows one of my favorite features: in-built power supply so no big dongle for that:

SMSL SU-6 Review back panel Bluetooth USB Stereo DAC Bluetooth.jpg


I think this is the smallest DAC with a built-in power supply.

SMSL SU-6 Measurements
As usual we start with our dashboard:
SMSL SU-6 Measurements USB Stereo DAC Bluetooth.png


I expected superb performance and we have it, especially in one channel. Averaging the two still leaves a very respectable score as far as SINAD is concerned (sum of distortion and noise):

best stereo dac reviewed.png


Zooming in:

best stereo dac reviewed reviewed.png


Dynamic range (how noisy the DAC is) is right up there as well:

SMSL SU-6 Measurements DNR USB Stereo DAC Bluetooth.png


Multitone shows superbly low distortion levels:
SMSL SU-6 Measurements USB Multitone Stereo DAC Bluetooth.png


Linearity is as good as it gets:


SMSL SU-6 Measurements USB Linearity Stereo DAC Bluetooth.png


Intermodulation distortion and noise is very low as well:

SMSL SU-6 Measurements USB IMD Distortion Stereo DAC Bluetooth.png


USB Jitter and noise shows some negligible (and utterly inaudible) unwanted tones:

SMSL SU-6 Measurements USB Jitter Stereo DAC Bluetooth.png


Switching to Coax input I initially saw a lot of jitter. But then remembered the options for Digital PLL (DPPL) so played with the 8 different ones in there to find the optimal one:

SMSL SU-6 Measurements Jitter Coax Stereo DAC Bluetooth.png


Typical trade off here is slow lock time vs performance. By slow lock time I mean if you switch sample rates, there may be longer delay before the DAC starts to play. Hence the adjustability.

Lots of filters are provided for you to play with:

SMSL SU-6 Measurements Filter USB Stereo DAC Bluetooth.png


Filter selection naturally impacts measured performance in our wideband distortion+noise test:

SMSL SU-6 Measurements USB THD+N vs Frequency Stereo DAC Bluetooth.png


Conclusions
Yes, we all get bored with one more desktop DAC with great performance. Here though, there is innovation in packaging and styling which works very well. The SU-6 definitely made me smile when I first powered it on in this regard.

I am happy to recommend the SMSL SU-6.

----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

Lambda

Major Contributor
Joined
Mar 22, 2020
Messages
1,118
Likes
873
Back panel shows one of my favorite features: in-built power supply so no big dongle for that
USB C can delver enough Power to charge a modern PC this needing an extra power supply makes no sense to me.

Performance is good I like the Design and that it has a Coax input.
But without balanced out this one is not for me.
 

Vini darko

Major Contributor
Joined
Jun 1, 2020
Messages
1,916
Likes
2,667
Location
Dorset England
Thanks for the review amir. That's a tempting dac. Does it have volume control? I like the selectable spidif locking , very good feature.
 

JSmith

Major Contributor
Joined
Feb 8, 2021
Messages
1,434
Likes
2,604
Location
Algol Perseus
If one doesn't need xlr or a remote, what a little cracker for this price. :)



JSmith
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
35,859
Likes
142,246
Location
Seattle Area
USB C can delver enough Power to charge a modern PC this needing an extra power supply makes no sense to me.
You would lose compatibility with millions of PCs if you try to power it using USB-C higher power profiles.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
35,859
Likes
142,246
Location
Seattle Area

Lambda

Major Contributor
Joined
Mar 22, 2020
Messages
1,118
Likes
873
You would lose compatibility with millions of PCs if you try to power it using USB-C higher power profiles.
So you can sell an extra USB hub and Power supply.

I know this is not part of typical ASR review but how mush power do modern DACs like this actually need?
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
35,859
Likes
142,246
Location
Seattle Area
What you you think, a few more months and this comes out in a balanced version at $199?
Unless they go with TRS jacks, it won't fit in this small box.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
35,859
Likes
142,246
Location
Seattle Area
I know this is not part of typical ASR review but how mush power do modern DACs like this actually need?
We know indirectly from SMSL producing a DAC without external supply. It worked great on Coax but not USB due to running out of power. It was said that the DAC itself could be powered by USB 2.0 but not once you added a display to it.
 

Budgeter

Member
Joined
Jan 19, 2019
Messages
96
Likes
50
You would lose compatibility with millions of PCs if you try to power it using USB-C higher power profiles.
As this has digital in, a power cable is a good choice to go with other devices (TV, smart devices, etc). However, for desktop use, there should be an additional option for USB power IMO.
 

MRC01

Major Contributor
Joined
Feb 5, 2019
Messages
2,286
Likes
2,435
Location
Pacific Northwest
Wow, this looks like my next desktop DAC. Excellent sound, internal power supply, a display showing the current rate, and a correct filter at 44 kHz that is flat at 20 kHz and fully attenuated at Nyquist.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
35,859
Likes
142,246
Location
Seattle Area
@amirm, any reason for the 3 dB difference in the channel SINAD?
I don't know. I often see that kind of differential. Sometimes one channel is more optimized as far as layout and connection to power than the other.
 

raif71

Major Contributor
Joined
Sep 7, 2019
Messages
1,593
Likes
1,465
This DAC must be hot off the oven coz the SMSL website doesn't list this as their product yet. I was searching for what type of dac chip this unit is using.
 

restorer-john

Master Contributor
Joined
Mar 1, 2018
Messages
8,295
Likes
22,526
Location
Gold Coast, Queensland, Australia
Realistically, this D/A is just as good as the ones further up the chart. They get the extra dB from doubling the voltage (4V+) using balanced. This gets where it does with 2V out.
 

PhnomPenhPaul

Member
Joined
Dec 20, 2019
Messages
25
Likes
27
Thanks @amirm for the review and congratulations on something I don't think I've ever seen before - your review of the SMSL SU6 is the only, and I mean the only, result that Google returned when I did a Google search [SMSL SU6]! As with @raif71 I wanted to know what chipset SMSL used [is it an ESS mobile chip or the Rohm used in their D300?] , but I guess until SMSL or Shenzhenaudio get it up on their web sites [or @amirm gets permission to open it up] I'll have to put up with my curiosity unsatiated. Like @amirm I'm really taken by the aesthetics of this little thing. I know I had a real whinge about the aesthetics of the display on the SU-9, but SMSL's latest offerings are much more to my liking with this and the D300 being very nice indeed. Really, for the price this is excellent and ought to be near the top of anyone's list looking for a sub $200 unbalanced dac. [Come on SMSL, stick some trs jacks on this thing and give the Topping E50 a run for its money:)]
 
Top Bottom