SMSL SU-9 Balanced DAC Review

[xhitespirit]

Thanks very much. Have you got a link to a high resolution image for the last photo? I cannot make out the opamps used?

Hi All,

I was wondering the same as Themystical, looking for a better picture of the output stage. Almost no detailled picture of this SU9 board on the net...

Anyway, I decided to buy one of this unit. Received few days ago, burned it about 20hours, then compared it directly to SMSL M200 and Topping D50s, I can yes, it sounds a bit better, probably less neutral, but more engaging. Indeed happy with the sound.

Finally I decided to open it, to have a proper look by myself at the inside. What a surprise ! Where are the announced 3 OPA1612 ? Even no OPA at all at the output stage, only transistors (which may cause this little warmer sound). Have a look by yourself at the attached pics. Am I wrong ?



In the absolute, I have no matter with that as long as it sounds well. But then, I have a problem with SMSL cheating with its specs (and corresponding price, as OPA1612 are quite 'expensive' chips) .

- have the specs changed since first release of this product ? If yes, specs and smsl website shoud have been updated !
- which product / what specs had really been tested here ?
- can I trust SMSL eyes closed anymore ?

Maybe an SMSL guy should take position on this ?

Nice day all !

 

[misterdog]

I have a problem with SMSL cheating with its specs (and corresponding price, as OPA1612 are quite 'expensive' chips) . .

Around £ 3 each when bought in industrial quantities.

https://uk.farnell.com/texas-instru...SMEC-Whoops-Newstructure-31Aug2020-Desktop-Hi

They are around the same price as the Texas Instruments OPA 551 as seen on your images.

Interesting first post. Welcome.

 

[Doodski]

It appears from a quick look that the red circled ICs are a Ti OPA551 high-current (380mA Typ), high-voltage (60V), operational amplifier.
https://www.ti.com/lit/ds/symlink/o...l=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA551
The yellow circled transistors are for output muting is my guess.

 

[xhitespirit]

Thank you for your answers ! Yes, my first post here

A closer look at the output stage


Does it look like an OPA551 ? I'm really not sure at all, but I can be wrong...

 

[misterdog]

Does it look like an OPA551

Clearly marked on the components if you use the digital zoom.

 

[Doodski]

Thank you for your answers ! Yes, my first post here

A closer look at the output stage
View attachment 99204

Does it look like an OPA551 ? I'm really not sure at all, but I can be wrong...

It's a Ti OPA 551. The only other obvious Ti component with a 551 number is a TLC551 and that is a timer.
You don't have a timer at the output section of this unit.
https://www.ti.com/lit/ds/symlink/t...l=https%3A%2F%2Fwww.ti.com%2Fproduct%2FTLC551

 

[misterdog]

Though in fairness the SMSL SU9 website does state.

3 high-end dual op-amps OPA1612 and a lot of audio grade components are used;

 

[xhitespirit]

Looking at mouser website, parts on the SU9 absolutely don't look like the same https://www.mouser.fr/Search/Refine?Keyword=OPA551
But as said, I can be wrong

Anyway, this can't explain SMSL saying "3 high-end dual op-amps OPA1612 and a lot of audio grade components are used"

 

[misterdog]

Looking at mouser website, parts on the SU9 absolutely don't look like the same https://www.mouser.fr/Search/Refine?Keyword=OPA551

Though it looks identical to this SOIC-8 package version.

https://www.mouser.co.uk/ProductDetail/Texas-Instruments/OPA551UA-2K5?qs=wgAEGBTxy7koNfcrrSme%2BQ==

There is more to being an electrical engineer than pulling the first product from the top of the page.
Like choosing between OPA 1612 or OPA 551.

 

[xhitespirit]

What kind of engineer would that be, to get the form factor wrong and purchase a TI OPA without any logo?

Capture from TI specs (https://www.ti.com/lit/gpn/opa551, page 28):

Still not convinced this is OPA551, and for sure not OPA1612...

 

[Doodski]

hat kind of engineer would that be, to get the form factor wrong and purchase a TI OPA without any logo?

Engineers, technologists, technicians or whoever order the part and the part ID is laser burned into the top of the component by Ti. Nobody gets to custom order with different marking on the top. It is what it is.

What does a drawing of the package prove?

Still not convinced this is OPA551, and for sure not OPA1612...

It is a Ti OPA551.

 

[misterdog]

What kind of engineer would that be, to get the form factor wrong and purchase a TI OPA without any logo?

Shame you cannot just zoom in on your own photo and read TI 551 on your post 441.
People might start to think you are a WUM after just 4 posts.

 

[Toku]

I checked the PC board, but OPA1612 is not used anywhere.
SMSL has done a trick again.

 

[xhitespirit]

I'm sorry guys, maybe I must buy new glasses ?!
I did have a good look at my own photo. I can well see 551, and so what ? This is not usual TI typo.
I also did have a good look at TI OPA551 specs, as written above. And so far, packaging specs does not correspond to what I see on my photo. Rectangle vs square, different edges/angles.
So, as said maybe I'm wrong, but allow me not to be convinced ! And I only trust what I see (reason I opened this box). And please be fair with your comments. If you guys have a picture of a real (not fake) OPA551 at hand that is exactly what I see on my photo, please share.

My post is not about who is right or wrong, but is here to alert that what we have in our SU9 Dacs, is not known, and is probably not what SMSL decribes in their specs. THIS is the important point.

Nice day all

 

[JohnYang1997]

It's just an 1612 in the vson package. Here's our 1612 with 541 marking

 

[JohnYang1997]

Matrix X sabre pro has been accused for the same shit before. Clearly this is not remotely the performance achievable with opa551.

 

[xhitespirit]

JohnYang, thank you for your input !
Indeed, had a look at TI OPA1612 specs, I can see this:

And

Very hepfull !

 

[JohnYang1997]

For SON package there's simply no 1612 number marking indicating the model but 'OVII'.

Furthermore, opa551 doesn't even have SON package. So it cannot be opa551.

 

[Veri]

View attachment 99239
For SON package there's simply no 1612 number marking indicating the model but 'OVII'.

Furthermore, opa551 doesn't even have SON package. So it cannot be opa551.
View attachment 99242

John to the rescue

 

[xhitespirit]

Things seems now clear I had a doubt while opening the SU9 box, thank you for eliminating it ! It appears these are 3 OPA1612 indeed. I learned something today.
I now say I can rely on SMSL specs.

And, as I state in my first post, I'm pretty happy with the sound of this DAC. SU9 sounds slightly better to my ears in direct comparison with the cheaper M200 and D50s. Sadly no more expensive DAC at hand (M400, D90, etc) to compare to. I'm wondering what benefits we can still get (dynamics, speed, sound staging...) ?
Have fun listening to your SU9 DAC !