SMSL SU-1 Stereo DAC Review

[seamon]

I have personally conducted tests to verify the changes in sound quality due to the differences in power supply that everyone is talking about.
I compared several mobile phone power adapters, linear power supplies, storage batteries, etc., but there was no difference at all. The discussion of sound quality changes due to differences in power supply is completely meaningless with today's well-designed DAC products. If there is a difference, there are other causes.

Now what am I supposed to do with my $500 PSU? /s

 

[Toku]

Now what am I supposed to do with my $500 PSU? /s

Please continue to use that PSU. It's a $250 PSU, so it would be a waste not to use it.

 

[multichannel_guy]

I have personally conducted tests to verify the changes in sound quality due to the differences in power supply that everyone is talking about.
I compared several mobile phone power adapters, linear power supplies, storage batteries, etc., but there was no difference at all. The discussion of sound quality changes due to differences in power supply is completely meaningless with today's well-designed DAC products. If there is a difference, there are other causes.

You will need highly resolving 500k speakers, 200k amp and a 500k purpose built fully treated room to hear such differences. If that still doesn't work, your ears are not good enough. You have hearing damage or your ears need to evolve more biologically. You didn't know this???

 

[raceskier]

I believe I have finally given up on using my SU-1 with my WiiM Pro in my system. The sound is not the issue. I have experimented with multiple DACs, and all are, to my ear, indistinguishable. The issue has been a compatibility with the WiiM. WiiM has issued regular updates, upgrading functionality, as well as addressing user reported issues. One of the issues WiiM has been working is dealing with the SU-1's ability to detect and decode the various sampling rates/depths seamlessly. Some of the firmware updates have allowed the SU-1 to operate flawlessly. Unfortunately, many have not. The latest firmware update, again clips off a fraction of a second at the beginning of each track. WiiM claims the compatibility with the SU-1 is the issue. Swapping the SU-1 with a Schiit Modi+ solves the issue. Again, there is no issue with the sound of the SU-1. Kind of disappointed that this otherwise excellent inexpensive DAC has this issue.

 

[Toku]

You will need highly resolving 500k speakers, 200k amp and a 500k purpose built fully treated room to hear such differences. If that still doesn't work, your ears are not good enough. You have hearing damage or your ears need to evolve more biologically. You didn't know this???

I know there are many audiophiles out there who think like you. I think ASR will be helpful for people like you.
I am an engineer who has been engaged in research and development of professional equipment for over 20 years at a Japanese company and has experienced various things. Therefore, only clear facts can be stated. But I don't like to slander people just because their ideas are different from my own.

 

[multichannel_guy]

I know there are many audiophiles out there who think like you. I think ASR will be helpful for people like you.
I am an engineer who has been engaged in research and development of professional equipment for over 20 years at a Japanese company and has experienced various things. Therefore, only clear facts can be stated. But I don't like to slander people just because their ideas are different from my own.

It was supposed to be a satirical post, the satirical suggestion of spending more than a million dollars to hear fidelity improvements on a sub 100 dollar dac. You didn't catch that?

 

[Delirium]

Some devices have OPA1612 built-in and most have LME49720. Out of the 3 SU-1s I bought, two of them had LME49720 inside. In one DAC I changed the operational amplifier to 2xOPA627 and in my opinion it sounds nicer. There may be less detail in the high end, but the music is easier to listen to. I also replaced the largest capacitors with Rubycon ZLH 2200uF 10V. The biggest change, however, is when I play with Gustard u18. Unlike USB, the sound is precise. There are almost no differences between SU-1 and 4xTDA1541 (NOS) or 4xPCM63-Y. When I play from USB, the action becomes blurry and imprecise (even if the SU-1 itself is powered by a linear power supply). Therefore, I recommend a good digital source with a femtosecond clock for this cheap dac.

 

[Toku]

It was supposed to be a satirical post, the satirical suggestion of spending more than a million dollars to hear fidelity improvements on a sub 100 dollar dac. You didn't catch that?

I'm sorry, but I couldn't understand it with my English ability.
As an elderly Japanese person with limited English proficiency, I sometimes misunderstand native speakers' English.
Thank you for your advice.

 

[rsc1]

Some devices have OPA1612 built-in and most have LME49720. Out of the 3 SU-1s I bought, two of them had LME49720 inside. In one DAC I changed the operational amplifier to 2xOPA627 and in my opinion it sounds nicer. There may be less detail in the high end, but the music is easier to listen to. I also replaced the largest capacitors with Rubycon ZLH 2200uF 10V. The biggest change, however, is when I play with Gustard u18. Unlike USB, the sound is precise. There are almost no differences between SU-1 and 4xTDA1541 (NOS) or 4xPCM63-Y. When I play from USB, the action becomes blurry and imprecise (even if the SU-1 itself is powered by a linear power supply). Therefore, I recommend a good digital source with a femtosecond clock for this cheap dac.

You must have some incredible ears!

 

[Delirium]

You must have some incredible ears!

Read/watch reviews, e.g. Gustard R26 or reviews of the U18 itself. Such an interface offers a lot. See what kind of quartz is in the SU-1 itself. I think they are not the best, in fact they are not even of average quality. Jitter can be heard without any problem.

 

[seamon]

Read/watch reviews, e.g. Gustard R26 or reviews of the U18 itself. Such an interface offers a lot. See what kind of quartz is in the SU-1 itself. I think they are not the best, in fact they are not even of average quality. Jitter can be heard without any problem.

But do you or do you not have incredible ears?

 

[rsc1]

Jitter shows some negligible spikes of no audible concern at all:
View attachment 280776

I think they are not the best, in fact they are not even of average quality. Jitter can be heard without any problem.

How do you know it's jitter that you're hearing?

 

[Delirium]

Suppliying a digital signal via USB, which is clocked with a weak clock, and from a good source with a femtosecond clock, what should it influence? Only for jitter. I'm sorry but I can hear it. It's not a "wow" change, but in my opinion it's important. I think it's more noticeable than replacing LME49720 with double OPA627. No, I don't have perfect hearing, I'm 47 years old, but I can hear the differences. Since you're asking this question, have you compared it or are you just writing it this way? Because I listen and hear.
Sorry, but I can hear the jitter. Try to send a signal to some old DAC through the CS8412 or AK4118 receiver. The difference is considerable. Did you hear? I think not. Maybe buy a cheap USB to COAX converter from Aliexpress and see what jitter does to the sound quality.

 

[Loftrocket]

Question to all.
What is the most hearable upgrade? Caps + opamp swap? What is better way to convert usb to coax? I mean which exactly converter to get to improve this tiny device?

 

[Delirium]

I will not answer this question which gives a greater effect. I made changes one by one. Finally, I changed the source between USB and Gustard u18. For every change there is improvement. How big? It is known that in audio everything is subjective The cheapest thing is to change the capacitors, then the operational amplifiers and finally the digital signal source. So in my opinion this is the best order

 

[rsc1]

Suppliying a digital signal via USB, which is clocked with a weak clock, and from a good source with a femtosecond clock, what should it influence? Only for jitter. I'm sorry but I can hear it. It's not a "wow" change, but in my opinion it's important. I think it's more noticeable than replacing LME49720 with double OPA627. No, I don't have perfect hearing, I'm 47 years old, but I can hear the differences. Since you're asking this question, have you compared it or are you just writing it this way? Because I listen and hear.
Sorry, but I can hear the jitter. Try to send a signal to some old DAC through the CS8412 or AK4118 receiver. The difference is considerable. Did you hear? I think not. Maybe buy a cheap USB to COAX converter from Aliexpress and see what jitter does to the sound quality.

Haven't heard the SU-1 myself, but I am potentially in the market for one.
I'm not questioning whether you are hearing something or not. Although I have younger ears (I'm 30), yours might be much more trained in advanced listening than mine. However, looking at Amir's measurements on this DAC, considering his claim that jitter is "negligible" and of "no audible concern", I find it interesting that you are convinced you're hearing jitter. That's why I was asking how you knew (other than your claim that can hear it). Not trying to dispute your claim - just interested in something that would back it up.

It is known that in audio everything is subjective

Whether something sounds good or bad is subjective. Measurements aren't. Although their importance is

 

[staticV3]

Question to all.
What is the most hearable upgrade? Caps + opamp swap?

Amir's measurements of the stock SU-1 show a completely transparent DAC.

No hardware mod can result in an audible boost in sound quality.

What is better way to convert usb to coax? I mean which exactly converter to get to improve this tiny device?

No extra converter, upgraded caps, or opamp swap may audibly improve the SU-1.

The stock SU-1 is as good as it's gonna get.

 

[TNT]

So, in fact, it's the ultimate DAC? No one needs any better?

How do you know this for sure?

(Serious question...)

//

 

[TNT]

I purchased and am using two SU-1s. Modifications to the SU-1 will be a noticeable upgrade.
SU-1 is very cheap, but don't underestimate it.

So, what did you do to them?

//

 

[staticV3]

So, in fact, it's the ultimate DAC? No one needs any better?

How do you know this for sure?

(Serious question...)

//

The audibility thresholds of distortion, noise, jitter etc have been well established and the SU-1 is well below all of them.

Here's an exhaustive thread discussing these thresholds:
https://www.audiosciencereview.com/...-thresholds-of-amp-and-dac-measurements.5734/