SMSL SU-9 Balanced DAC Review

[Dwander]

As I understand it, you are using a Y-Splitter "in reverse" to combine the L/R channels into one RCA output? If so: Don't! You're essentially shorting the channels - the output stages might not like that and the result won't be a correctly summed signal. If you really want to downmix stereo->mono on RCA, you can either use a DSP device or a passive summing box like this. If you can avoid the summing because the sub has stereo inputs, it's probably best to use those. I'd expect that the subwoffer has the correct summing circuit built in.

Yep, that’s what I was asking. I’ll just sum it at the subs then. I was just doing it this way to snake less cables to the subs. But It’s completely doable to run separate L&R signals to it. I basically have two DACs for two different systems in the same room. Neither DAC has a sub-out. So I run summed signals from each DAC (separately) into an RCA switch. Then from the switch to the subs. This way I can easily switch the subs from system to system depending which I’m giving priority to at the moment. But the rca switch is a stereo switch so it’s just a matter cabling it a little different.

Thanks for the help.

 

[archerious]

Have a look at the SU-9n instead

That suggestion did not age well.

 

[jasonq997]

Will this unit allow the user to do the following? --- I would like to set the balanced output to act as a preamp (volume control) and I would like to set the RCA output to fixed line out. I would like both sets of outputs to run at the same time with these settings.

 

[iamsms]

Will this unit allow the user to do the following? --- I would like to set the balanced output to act as a preamp (volume control) and I would like to set the RCA output to fixed line out. I would like both sets of outputs to run at the same time with these settings.

i have a su-9, don't think you can do that.

 

[maierc]

Hey, i got a new SMSL SU-9 yesterday and was wondering if i am fine with the firmware revision regarding the distortion fix.
I couldn't really find any safe way to determine the version outside of measuring (i tried and it looked okay to me, but i have no clue what i am doing and if my setup was right x) ).
The only thing i noticed is that my label says "Blakb" instead of "Black" like on all pictures ive seen, which could mean that this is a revision b or something?
Also my version screen has no 2020 which was mentioned by Ryctor87 on his apparently fixed unit, but i think he was the only one mentioning it.

The SMSL support only referred to shenzhenaudio and i havent heard back from them yet.

 

[norcalscott]

Hey, i got a new SMSL SU-9 yesterday and was wondering if i am fine with the firmware revision regarding the distortion fix.
I couldn't really find any safe way to determine the version outside of measuring (i tried and it looked okay to me, but i have no clue what i am doing and if my setup was right x) ).
The only thing i noticed is that my label says "Blakb" instead of "Black" like on all pictures ive seen, which could mean that this is a revision b or something?
Also my version screen has no 2020 which was mentioned by Ryctor87 on his apparently fixed unit, but i think he was the only one mentioning it.

The SMSL support only referred to shenzhenaudio and i havent heard back from them yet.

View attachment 223421View attachment 223423

As you mentioned, my understanding is that the updated firmware does not show "2020" in the screen you posted. I purchased mine last year and my firmware is the same as yours and I have not experienced any issues at all. At this point, I would be sure that all units in the field have been updated, especially from Shenzenaudio.

 

[Tomas Brabec]

5.3 volts.

Please let me know what is the voltage also on RCA for settings 99. Thank you.

 

[euge_lee]

Generally yes... unless there is a switch/toggle/selector for RCA/XLR.


JSmith

Some google searches on using both XLR and RCA outputs simultaneously have me confused. Some talk about it taking the XLR down to the "lowest common denominator" and effectively making it unbalanced. Others talk about resistance levels, etc. All too confusing to me.

My goal is to use my SU-9 XLR to a Topping PA5 to power my desktop speakers... then have the RCAs simultaneously run to my powered subwoofer. Can I do this without any "degradation" of what the PA5 sees in terms of a unbalanced signal at full power?

 

[JSmith]

Some talk about it taking the XLR down to the "lowest common denominator" and effectively making it unbalanced.

Generally on these DAC's, RCA is a few dB of SINAD lower than XLR. This DAC measures at 120dB SINAD... thus I see no issue here.

Are you running a pre-amp or using the DAC as a pre?


JSmith

 

[euge_lee]

Generally on these DAC's, RCA is a few dB of SINAD lower than XLR. This DAC measures at 120dB SINAD... thus I see no issue here.

Are you running a pre-amp or using the DAC as a pre?


JSmith

Using it as a pre-amp; although I have a nice Parasound pre-amp just sitting in the closet (doesn't support balanced though).

I'm not too worried about SINAD from the SU-9 being an issue either... I just want to use the SU-9 as my DAC/PRE to my 2.1 system consisting of a Topping PA5 and a powered subwoofer. So the XLR will be at full output voltage to the PA5 while simultaneously sending standard unbalanced voltage to the active subwoofer?

 

[mario_rouge]

Using it as a pre-amp; although I have a nice Parasound pre-amp just sitting in the closet (doesn't support balanced though).

I'm not too worried about SINAD from the SU-9 being an issue either... I just want to use the SU-9 as my DAC/PRE to my 2.1 system consisting of a Topping PA5 and a powered subwoofer. So the XLR will be at full output voltage to the PA5 while simultaneously sending standard unbalanced voltage to the active subwoofer?

the crossover problem remains

 

[Tomas Brabec]

Please let me know what is the voltage also on RCA for settings 99. Thank you.

When I have the volume at 99, the resulting sound is hoarse, overblown. This is for transistor, tube and headphone amplifiers (connected via RCA). I have to set the volume to 78, then it's fine. Has anyone encountered this? Is there something wrong with my SU-9 ? Topping D50s did not do this. Today I connected DAC to headphone amplifier SMSL SP200 over RCA and XLR outputs. The connection with XLR and volume 99 is ok, the sound is excelent. With RCA connection is music hoarse. Problem is with RCA definitely.

 

[euge_lee]

the crossover problem remains

I have taken measurements and have integrated the subs well. The speakers can easily play full range at the volumes I listen at and the subwoofers are nicely integrated to supplement the mains.

 

[Edgar_moz]

Hello,
Yesterday I received my new smsl su-9.
Taking it out of the box I noticed that when I turn it over it sounded like there was a broken screw (?) moving back and forth.
Has anyone else noticed anything like this?
This is my first dac and I have no experience at all. I'm afraid it might be defective and cause a problem with the sound.

 

[euge_lee]

the crossover problem remains

Actually, since I already stole my Martin Logan 10" sub from the home theater, I decided to steal the 8" ML sub too... and the MiniDSP 2x4HD... so now I have a proper crossover set for the ELAC Debut Reference and summed L/R signals going to the subwoofers with proper bass time alignment and room correction.

A good excuse to now get a whole new and proper subwoofer setup for the HT, LOL.

 

[mario_rouge]

I used a studio subwoofer with the internal crossover and it works quite well. a 10" jbl lsr310s.

 

[Nate29]

If I only have one source, and it’s mostly digital, do I benefit anything from connecting it to a preamp before a power amp? I already own this smsl u-9.

Let’s forgot about tube gain stage pre. I don’t want to discuss that on ASR, I understand the crowd I’m talking to

The big difference here is digital volume control vs discrete with something like a pre90. Do I lose any fidelity by going with digital volume control?

Would getting a pre amp improve sound quality or is the SE/balanced output from the smsl u9 good enough to plug directly into a power amp?

 

[Trell]

If I only have one source, and it’s mostly digital, do I benefit anything from connecting it to a preamp before a power amp? I already own this smsl u-9.

Let’s forgot about tube gain stage pre. I don’t want to discuss that on ASR, I understand the crowd I’m talking to

The big difference here is digital volume control vs discrete with something like a pre90. Do I lose any fidelity by going with digital volume control?

Would getting a pre amp improve sound quality or is the SE/balanced output from the smsl u9 good enough to plug directly into a power amp?

Have you seen this thread?

Do I benefit of a preamp instead of only dac

Do I benefit purchase a preamp when my dac with volume control can drive the power amp directly? Please explain

www.audiosciencereview.com

 

[Nate29]

Have you seen this thread?

Do I benefit of a preamp instead of only dac

Do I benefit purchase a preamp when my dac with volume control can drive the power amp directly? Please explain

www.audiosciencereview.com

Let me check that thread out! Thanks

 

[amarsicola]

Long story short: no benefit in having a preamp, digital volume is as good as analogue. But PLEASE make sure the maximum output voltage of your DAC (I guess SU-9 has 4 or 5 volts with xlr out) does not put in clipping your amplifier. An amplifier in clipping can seriously damage your speakers. If this risk is possible, then check this post https://www.audiosciencereview.com/forum/index.php?threads/topping-d70s-fried-my-speakers.38706/ unfortunately chi-fi dacs can have buggish software that can randomly reset the volume to the max. In my case the topping D70S had a max voltage of 5v while my amplifier (Audiophonics Purifi) was designed to clip at 4v. The dac unpredictably set the volume to the max and my speakers got fried... I am considering a Nobsound volume control (and Pre90 when i have some money) to avoid this in the future