SMSL SU-1 Stereo DAC Review

[kibs]

After several days of use, notes
- Using windows 11,haven't had to install any drivers, just plug and play via supplied USB cable
-Haven't heard the infamous "pop noise"
-Have used 2 RCA Y splitters to give 4 outputs, 2 to receiver(in direct mode, no LFE out) and 2 to subwoofer line level inputs.
- Subjective opinion - pristine audio quality, very pleased with sound

 

[Platypus20]

I’m glad they work for someone, I had 2 fail in about 7-10 days

 

[Toku]

After several days of use, notes
- Using windows 11,haven't had to install any drivers, just plug and play via supplied USB cable
-Haven't heard the infamous "pop noise"
-Have used 2 RCA Y splitters to give 4 outputs, 2 to receiver(in direct mode, no LFE out) and 2 to subwoofer line level inputs.
- Subjective opinion - pristine audio quality, very pleased with sound

Most DACs can be used with Windows audio systems without the need to install drivers. However, all music files are always resampled and output to the sampling rate and bit rate preset on the Windows system. In some cases, a limiter operates and compresses the signal.
If you want to avoid such behavior and play the original file as it is, install the driver and play it in ASIO or WASAPI mode with a separate music player.

 

[schmalgausen]

Even foobar2000 doesn't recommend to use ASIO nowadays.

 

[Toku]

Even foobar2000 doesn't recommend to use ASIO nowadays.

You should not make such baseless statements.
foober2000 has excellent scalability depending on the settings, but on the other hand, if you do not understand its functions well, it may become unstable or not work properly.

 

[schmalgausen]

Please note that this component is meant for systems where ASIO is the only available output method. It is highly recommended to use the default output modes instead of ASIO. Contrary to popular "audiophile" claims, there are NO benefits from using ASIO as far as music playback quality is concerned, while bugs in ASIO drivers may severely degrade the performance.

foobar2000: Components Repository - ASIO Output

foobar2000

www.foobar2000.org

 

[DSJR]

I know that listening sound impressions are very objective and cannot be measured, but I compared the SU1 to SMSL M300mk2 and Topping E30 in some listening "test". Because I have no such high quality measurement equipments like amirm uses. Tried to match volume levels.
Interestingly the better built M300mk2 with older but top AK4497 was worse to me. Somehow less. Then compared to the original E30, the difference was even more. Anyways the overall differences are subtle. Surely, it does not mean anything because listening a whole sound system with my own ears are not reproductible but I was surprised how this cheap DAC, with new lower level dac chip and not as good measurements could sound better.

You may just find the difference is in volume matching and the fact you can see them. heard without knowing which was which, it's arguable that said sonic differences would melt away.

There's a VERY fine line here though. I've been told off for recalling hearing differences in some cables when I was in the industry and demming every day. Said differences were fully repeatable on many systems and in different rooms but as I have no means of measuring said bits of wire and listening 'blind' these recollections are just that, sighted recollections with no evidence apart from my word and others from my times around and about.

My SU1 is all but hidden now although I can get to it for changing input. I switched from a wall-wart USB supply to powering it directly from the PC via a nice looking (not silly money) 3mm long USB A-C cable and can't tell any difference. It does the job superbly and allows me to hear into recordings without effort - job done Stuff I've used in this rig in the past (digital and certain amps) tended to make everything sound more the same - 'nice' in other words if you understand the bland meaning of 'nice.'

 

[Golf]

[...] powering it directly from the PC via a nice looking (not silly money) 3mm long USB A-C cable [...]

Yep. It is almost always a good idea to keep cables as short as possible

 

[DSJR]

Yep. It is almost always a good idea to keep cables as short as possible

I bought what I needed for the job, crossing fingers that 3m wasn't too stupid long for the task- and I happen to like the woven sleeving on such wires even if they serve no useful function other than to look nice The 'audio' interconnects are a foot (30cm) long though and are from memory as I made them decades ago, RG59 based using copper innards I believe rather than copper plated steel which seems common nowadays

 

[trungdtmc]

Even foobar2000 doesn't recommend to use ASIO nowadays.

I have measured and compared the results between the default output and using ASIO. If ASIO fully supports 24/32 bit or DSD (foo_out_asio+dsd), the default output is only 16bit quality.

 

[kibs]

Most DACs can be used with Windows audio systems without the need to install drivers. However, all music files are always resampled and output to the sampling rate and bit rate preset on the Windows system. In some cases, a limiter operates and compresses the signal.
If you want to avoid such behavior and play the original file as it is, install the driver and play it in ASIO or WASAPI mode with a separate music player.

Installed the driver and Foobar2000 but the driver tells me "Asio not active"
Is there an extra step I'm missing? How does one play music in Asio mode? I thought setting device output on foobar to "smsl usb dac exclusive" would be enough.
Would playing music on usb via an android box connected to the DAC give unadulterated output?

 

[staticV3]

Is there an extra step I'm missing? How does one play music in Asio mode? I thought setting device output on foobar to "smsl usb dac exclusive" would be enough.

Exclusive is Wasapi Exclusive.

For ASIO, you need to install the foo_out_asio component, set Foobar's output to ASIO, then select the appropriate ASIO interface.

That being said, Wasapi Exclusive is just as good as (arguably better than) ASIO, unless you need to play native DSD.

 

[kibs]

Exclusive is Wasapi Exclusive.

For ASIO, you need to install the foo_out_asio component, set Foobar's output to ASIO, then select the appropriate ASIO interface.

That being said, Wasapi Exclusive is just as good as (arguably better than) ASIO, unless you need to play native DSD.

Thanks, that installation worked

 

[tlr125]

Fake LME49720?
I took a picture the DAC inside. Everything is similar to other one's except the LME49720 output opa. The strange here, that there is no "pin 1 mark". It' missing there, as you can see on the photo. The TI's documentation says there should be there. I can see many types (small dot, a reverse bump, a small nook, etc...) on other one's ebay, ali, sites photos and the sites selling this IC also there.
What do you think? Is that a fake one or just a new series, where TI does not put it there.

here is another one unit, that's strange

 

[Toku]

I have experienced several times that IC packages differ depending on the manufacturing lot at the time.
If your question remains unanswered, please contact SMSL or TI directly instead of discussing it here.

 

[pablolie]

I have experienced several times that IC packages differ depending on the manufacturing lot at the time.
If your question remains unanswered, please contact SMSL or TI directly instead of discussing it here.

Indeed they do. Component manufacturers are always obsoleting stuff and give manufacturers application guides on how to easily migrate their existing designs. Happens everywhere and all the time, and has zero impact on performance the vast majority of the time (in fact many times it's an improvement).

 

[hkrooner]

May I ask if there is any way to set the SU-1 to output at a fixed 1-Vrms maximum?

Mine is currently outputting to my Zeppelin Wireless via the 3.5mm aux-in jack, but I've just heard from B&W its aux input is rated at a 1-Vrms maximum and there is really bad clipping without attenuation.

I'm using a passive amp (the JDS Labs Ol Switcher) between the SU-1 and the Zeppelin, but that obliges me to leave the potentiometer always at middle volume, and the Zeppelin at lower volume too, to minimize possible accidents.

My source is a WiiM Mini (feeding the SU-1 via optical in), in turn also getting sound from a projector+Google Chromecast TV (via aux in), and there is wide volume variation in the WiiM Mini depending on whether I feed it from the projector or, say, Tidal.

I'm thus always needing to fiddle with the potentiometer and looking at the risk of an accident volume-wise.

It would be great if I could limit the SU-1's volume output somehow.

 

[kibs]

May I ask if there is any way to set the SU-1 to output at a fixed 1-Vrms maximum?

Mine is currently outputting to my Zeppelin Wireless via the 3.5mm aux-in jack, but I've just heard from B&W its aux input is rated at a 1-Vrms maximum and there is really bad clipping without attenuation.

I'm using a passive amp (the JDS Labs Ol Switcher) between the SU-1 and the Zeppelin, but that obliges me to leave the potentiometer always at middle volume, and the Zeppelin at lower volume too, to minimize possible accidents.

My source is a WiiM Mini (feeding the SU-1 via optical in), in turn also getting sound from a projector+Google Chromecast TV (via aux in), and there is wide volume variation in the WiiM Mini depending on whether I feed it from the projector or, say, Tidal.

I'm thus always needing to fiddle with the potentiometer and looking at the risk of an accident volume-wise.

It would be great if I could limit the SU-1's volume output somehow.

How are you powering the SU-1? I've noticed that when I use USB 2.0 as input+ power supply I have to turn up my amp higher, as opposed to using USB 3.0. Suspecting lower output voltage from using USB 2.0 as the SU-1 is getting a max of 2.5 watts vs the 4.5 watts it can get from USB 3.0.

 

[hkrooner]

Thank you so much! I think the problem was not so much the difference between 2.5 and 4.5w, but probably the fact that I was way above this!

I found that 2.5 did not change volume so much in relation to 5w, at least not to my untrained ears, testing with both my headphones and the Zeppelin, but sound quality was a tad impaired at 2.5. Maybe my power source -- an old 5V / 0.5a adapter.

In any event, it's clear now that the power source matters a lot for the SU-1, so thanks for drawing my attention to that.

At proper 5w, things improved a lot. Maybe there was a combination of factors as the sound entered the Zeppelin at high volume and already somewhat clipped by the SU-1. The potentiometer was probably helping a bit (and I still need it), but it's much better now.

I still wish there was a way to half the SU-1's output, though.

 

[staticV3]

I still wish there was a way to half the SU-1's output, though.

Since you're feeding the SU-1 with your WiiM Mini, you should be able to effectively halve the SU-1's output by setting a volume limit in the WiiM Home App.

Go to Device->WiiM Mini->Cogwheel->Audio Settings and there, disable Fixed volume output and set the Volume Limit to something <100.

I don't know if 50% translates to -6dB (=1Vrms) or not, but that can easily be assessed with a multimeter.