SMSL SU-1 Stereo DAC Review

[Toku]

A few things, I'd like to discover more about this DAC.

1st these measurements look comprehensive, and impressive. Much respect for this quality of independent testing.

1. The frequency response, down 0.3dB at 20K, also gave me some concern. What is not immediately obvious to me, cos I may have missed this detail if it was contained in the report, is how loud was the signal, for the Frequency Response published on this thread, by Amir. I'm assuming these were measured at 0dBFS, i.e maximum

2. If the FR measurement was done at a lower level, say -2 dBFS, would this yield a better frequency response?

I think you are too concerned about the numbers from the measuring machine.
A decrease of 0.3dB/20kHz is completely undetectable to the human ear, and the numerical value is only a difference in the measurement error range level. A -3dB drop would be perceptible to people with good hearing.
Also, for low-level signals like DAC, there is almost no difference in FR depending on the output level.

 

[theREALdotnet]

I‘ve added a SU-1 to my system a few days ago, replacing a Topping E30 for subwoofer channel duties in my DLBC setup. I like it because I could buy it new for less than I got from selling the E30, because it doesn’t require an external power supply and because it has no display. It also has better theoretical performance, but of course doesn’t sound any different – except for what I learned here. This only applies to multi-channel setups (like DLBC) using different model DACs, of course.

I wish I had done delay comparisons like that with the E30, but it only occurred to me when the DAC was packed up for shipping.

 

[OK1]

I think you are too concerned about the numbers from the measuring machine.
A decrease of 0.3dB/20kHz is completely undetectable to the human ear, and the numerical value is only a difference in the measurement error range level. A -3dB drop would be perceptible to people with good hearing.
Also, for low-level signals like DAC, there is almost no difference in FR depending on the output level.

For whatever it's worth, I did check as I own a once highly revered professional quality audio interface - an EMU 1212M Audio interface, (the M stood for Mastering Grade) and these were a hot item, in the mid noughties, and even today, still quite respectable kit.

And these are the manufacturers specs, which I have no reason to doubt, cos I think Sound on Sound also measured them at the time, and EMU was a pretty reputable business, unfortunately no longer in existence.

ANALOG LINE OUTPUTS (2)
Type
Balanced, low-noise, 3-pole low-pass differential filter,
AC-coupled
D/A Converter CS4398
Level (software selectable)
Professional: +4dBu nominal, 20 dBu maximum
(balanced)
Consumer: -10 dBV nominal, 6 dBV maximum (unbalanced)
Frequency Response (20 Hz - 20 kHz): +0.0/-0.35 dB
Dynamic Range (1kHz, A-weighted): 120 dB
Signal-To-Noise Ratio (A-weighted): 120 dB
THD + N (1kHz at -1dBFS): -105 dB (.0006%)
Stereo Crosstalk (1kHz at -1dBFS): < -115 dB
Output Impedance 560 ohms

So with proper consideration, if I am still happy with the EMU 1212M, I don't think I or anyone else should be bothered about the -0.3dB dip at the top of the SMSL's frequency response.

My point is rather than think of one product in isolation, it helps to ask - how does this compare to other things. And in this case on reflection, there is nothing bothersome about the SMSL SU-1.

Purely from a point of discussion, the challenge is today, almost every DAC out there, especially the DAC's in gear that I'm more familiar with, for professional studios, has ruler flat frequency responses in their output. within +/- 0.1 dB, and we are so spoiled. How meaningful these eye watering specs are, in practice, is another matter.

The other question is - we hope the manufacturers are not sending Amir cherry picked "golden" samples..., from their assembly line.

 

[djlotfi]

Hello,
this unit is just fantastic for the price, the only cons is that there is no stand by or trigger fonction, chinese manufacturers should be more concerned by these environnementals matters

my question, is there a solution to add or a DIY solution to make a usb 5v trigger ?

 

[TonyJZX]

i think the thing is these things in use (ie. playing sound) probbly dont use much more power than it on no ssound (ie. idle)

so why would you go to the trouble of putting in idle modes and the issues of going in and out of modes to save... what? pennies a quarter?

i have an smsl a300 and a smsl c100 on a 2nd system and i just left it on and really i couldnt tell with my bill

on the other hand i often leave workstations like 8 cores and GPUs and monitors on 24/7 and its like... ok

my power bill is dominated by water heating and cooking

if you're powering from a pc is there some way to trigger the unit?

off the wall? some kind of smart power board?

 

[staticV3]

Hello,
this unit is just fantastic for the price, the only cons is that there is no stand by or trigger fonction, chinese manufacturers should be more concerned by these environnementals matters

my question, is there a solution to add or a DIY solution to make a usb 5v trigger ?

If you're using the SU-1's USB input for audio transmission, then the DAC should turn on/off with your PC.

If not, then your PC has special, always on USB ports, which you should be able to turn off in the BIOS.

If you're instead using Coax/Toslink/Bluetooth for Audio input, then you could add auto on/off using a master/slave power strip.

Simply set your Amp, TV, or any other power hungry piece of equipment that you use alongside the SU-1 as the Master, then the SU-1 plugged via a common phone charger into one of the Slave outlets, will turn on/off with it.

 

[djlotfi]

If you're using the SU-1's USB input for audio transmission, then the DAC should turn on/off with your PC.

If not, then your PC has special, always on USB ports, which you should be able to turn off in the BIOS.

If you're instead using Coax/Toslink/Bluetooth for Audio input, then you could add auto on/off using a master/slave power strip.

Simply set your Amp, TV, or any other power hungry piece of equipment that you use alongside the SU-1 as the Master, then the SU-1 plugged via a common phone charger into one of the Slave outlets, will turn on/off with it.

Hello thank you for your reply

i am using it it with a wiim mini connected in toslink, no USB use, my amp is an Audiolab 6000A,unfortunately no outlets or 5V USB output.

 

[staticV3]

i am using it it with a wiim mini connected in toslink, no USB use, my amp is an Audiolab 6000A,unfortunately no outlets or 5V USB output.

Use a master/slave power strip.

 

[djlotfi]

Use a master/slave power strip.

thank you

 

[morozzz_2003]

Hi all! I have a trouble, win 11, drivers from official site, but maximum resolution via usb is 32\384 (In audio settings)... What i doing wrong? Thanks!

 

[staticV3]

Hi all! I have a trouble, win 11, drivers from official site, but maximum resolution via usb is 32\384 (In audio settings)... What i doing wrong? Thanks!

You're not doing anything wrong.

The highest that Windows can do is 32/384.

If you want to play higher sample rates, then you need to use ASIO output via a music player like foobar2000, bypassing Windows' native audio pipeline.

 

[morozzz_2003]

You're not doing anything wrong.

The highest that Windows can do is 32/384.

If you want to play higher sample rates, then you need to use ASIO output via a music player like foobar2000, bypassing Windows' native audio pipeline.

Thanks a lot for information! Yes, i select ASIO in foobar settings...
PS After es9018k2m, this dac so wonderfull!

 

[Silvestrus]

I found that it is a little bit lean in bass region. I was constantly thinking to add subwoofer to my system. Yesterday, I've returned Micromega Mydac and everything is ok now. SMSL is great in highs, female vocals... It has plenty of details. But it seems that it lacks in male vocals a little bit. Missing a little bit of chestiness. Bass is lean. Fast and precise, but it lacks volume. My opinion after one month of use.

 

[DavidGA]

Discounted to $70.39 on Amazon today.

 

[Bleib]

Discounted to $70.39 on Amazon today.

Also cheaper @ https://shenzhenaudio.com/collectio...-dsd512-pcm768khz-32bit-usb-mqa-audio-decoder

 

[Mikig]

The more I use it, the more satisfied I am with this Dac.
The only modification I would make to the splendid SU-1 would be balanced outputs, even TRS would be fine.
For the rest I find it perfect. It has everything that interests me: it works really well, it has no display, it has no headphone outputs, volume, adjustments, filters and various messes.

 

[Bru87tr]

This was actually at that price on Amazon for 2 weeks. This past week it went up and just today it went back down.

I think the SU-1 is excellent. I’ll prob buy a second one to put away in case they stop making them.

 

[theREALdotnet]

I think the SU-1 is excellent. I’ll prob buy a second one to put away in case they stop making them.

What worries me is that there is no trace of the SU-1 on the S.M.S.L website that I could find. Is it already discontinued?

I just ordered another one, for any future subwoofer additions

 

[staticV3]

What worries me is that there is no trace of the SU-1 on the S.M.S.L website that I could find. Is it already discontinued?

It was never listed on the websites in the first place.

 

[theREALdotnet]

It was never listed on the websites in the first place.

Interesting, any idea why? Also, where does the product description at shenzhenaudio.com (for example) come from? Did S.M.S.L provide it to them without putting it up on their own site? Very strange.