SMSL SU-9 Balanced DAC Review

[cursive]

This is technical information about my desktop amplifier input:

Input Impedance: 100Kohms
Input Sensitivity: 500mV at 1KHz and 8 ohms for 100 watt output

Is right for DAC output on RCA?

This DAC should work great for you Lucaxxaa. Rule of thumb is the input impedance of the amp should be at least 10x the output impedance of the DAC to have good voltage matching. The RCA output impedance on the SU-9 is 122 ohm, so you should have no problems.

Be sure your amplifier has an input impedance above 3.7k Ohm (10 to 1 ratio) for XLR output and half and 1.3 k for RCA.

You can see Amir mentioned this in the review briefly, which put my mind at ease when I was pairing with an amp as well.

 

[Aardappel]

This DAC should work great for you Lucaxxaa. Rule of thumb is the input impedance of the amp should be at least 10x the output impedance of the DAC to have good voltage matching. The RCA output impedance on the SU-9 is 122 ohm, so you should have no problems.



You can see Amir mentioned this in the review briefly, which put my mind at ease when I was pairing with an amp as well.

@cursive - what happens if you were to add an inline attenuator between the DAC and the amp? To attenuate about 10dB for example. Isn't that essentially a resistive load that you're adding so that should be fine no?

 

[cursive]

@cursive - what happens if you were to add an inline attenuator between the DAC and the amp? To attenuate about 10dB for example. Isn't that essentially a resistive load that you're adding so that should be fine no?

Sorry, but that's a little beyond my knowledge, hopefully someone else can chime in about that. I definitely don't think any harm could come from adding an inline attenuator, as long as it's audibly transparent.

I'm just not exactly sure why you would do this, unless the volume from the SU-9 at really low levels is too loud?

 

[DarkStar73]

Got a SU-9 today and it is definitely an upgrade from my Modi 2 Uber. I am using the device in fixed volume mode going into my preamp. I can't turn the volume past 20% on the preamp without it becoming way too loud. With the Modi, 50% volume was the sweet spot. This might be a dumb question but why the difference? Below is my current setup. The Adcom is being replaced by a Freya+ once they are back in stock.

Raspberry Pi 4
SMSL SU-9
Adcom GTP-400 preamp
Murano P200S monoblock amps
Acoustic Research Classic 18 speakers

 

[elevensheep]

Got a SU-9 today and it is definitely an upgrade from my Modi 2 Uber. I am using the device in fixed volume mode going into my preamp. I can't turn the volume past 20% on the preamp without it becoming way too loud. With the Modi, 50% volume was the sweet spot. This might be a dumb question but why the difference? Below is my current setup. The Adcom is being replaced by a Freya+ once they are back in stock.

Raspberry Pi 4
SMSL SU-9
Adcom GTP-400 preamp
Murano P200S monoblock amps
Acoustic Research Classic 18 speakers

Try turn the volume to 94, this will give you roughly a 2v RCA / 4v XLR output

 

[DarkStar73]

Try turn the volume to 94, this will give you roughly a 2v RCA / 4v XLR output

The volume is always at 99 in fixed mode. If I change it to variable mode, isn't the signal now running thru 2 preamps since the SU-9 acts as a preamp when in variable mode. I've already tested the SU-9 without the Adcom and I prefer the sound with the Adcom.

 

[wyup]

The volume is always at 99 in fixed mode. If I change it to variable mode, isn't the signal now running thru 2 preamps since the SU-9 acts as a preamp when in variable mode. I've already tested the SU-9 without the Adcom and I prefer the sound with the Adcom.

AFAIK, it's not really a preamp, but digital attenuation. It should lower the voltage output with minimal loss to give more headroom to your preamp.

 

[DarkStar73]

I've had the DAC for a day and it sounds great, but I think I received a defective unit. Just noticed nothing was coming out of the right channel. Checked all the connections and all good there. Resetting the DAC fixed the issue. Anybody else experienced this?

 

[Vapor9]

I have the project pre box s2 digital DAC, is the su-9 a big upgrade. Thinking about purchasing this the M400 or topping D90 but not sure the extra cash is worth it. Looking to move toma balanced DAC. Any advice is much appreciated. Thanks.

Just replaced my pre box s2 with the SU-9. The bass is most certainly deeper, fuller and more accurate with the 9. The midrange is also fuller with details a bit easier to follow. Vocals are also a bit easier to follow in deep mixes and less shrill. For instance, 'Valerie' by Amy Winehouse is a very upfront recording that comes off a bit harsh with the pre box - the su-9 seems to smooth it a bit, but not at the expense of it sounding less realistic. In fact, the vocals, are for me, one of the 9s best attributes. As far as high-frequencies, I know a lot of reviews say that they are a bit recessed, but it may just be due to increased low end that makes it seem that way. Acoustic guitars, synths or cymbals are etched nicely with great texture and impact. If you find them a bit softened, it might be worth trying the 'crystal 1, 2 or 3' settings in sound color. I've not played around much yet with the settings. The SU-9s best feature for me is the improved sense of space and soundstage. It's certainly opened up and put individual instruments out there on a larger stage. I'm using a Wyred4Sound preamp so your mileage may vary, but I'm very happy with the SU-9. That said, I still have a lot of respect for the s2, but the SU-9 is certainly an upgrade for me.

 

[brad pitt]

I got a SMSL SU-9 and feels that the power is not amazing.
According to my oscilloscope measure, the RMS Level is 2.7v !

 

[cursive]

I've had the DAC for a day and it sounds great, but I think I received a defective unit. Just noticed nothing was coming out of the right channel. Checked all the connections and all good there. Resetting the DAC fixed the issue. Anybody else experienced this?

Haven't heard of this, if you're still within your return window, I'd just keep an eye on it, or maybe reach out to your vendor, and make them aware of it. Hopefully it was just a one time fluke.

I got a SMSL SU-9 and feels that the power is not amazing.
According to my oscilloscope measure, the RMS Level is 2.7v !

Hey brad, I was just about to ask if anyone knows, or has measured the RCA out voltage of this dac. Is 2.7v the output voltage from the RCA at 99 volume? That seems about right honestly as 2.0v is pretty common for RCA. The balanced out should be much higher though, Amir tested it at 5.3v.

 

[DarkStar73]

So far, it has been a one time fluke. I have to 3/2 to return the DAC so if it does happen again, I will return it. I have let the vendor know about it. They said if it happens again return it so they can look at the DAC. Other than that, I am extremely happy with the sound. Night and day difference as compared to my Modi 2 Uber!!

 

[brad pitt]

I got a SMSL SU-9 and feels that the power is not amazing.
According to my oscilloscope measure, the RMS Level is 2.7v !

Solved !
I was mesurearing with one standard probe. For differential like XLR, a differential probe is needed (or 2 standard probes with A-B with the oscilloscope).

 

[brad pitt]

Haven't heard of this, if you're still within your return window, I'd just keep an eye on it, or maybe reach out to your vendor, and make them aware of it. Hopefully it was just a one time fluke.



Hey brad, I was just about to ask if anyone knows, or has measured the RCA out voltage of this dac. Is 2.7v the output voltage from the RCA at 99 volume? That seems about right honestly as 2.0v is pretty common for RCA. The balanced out should be much higher though, Amir tested it at 5.3v.

I just measure with oscilloscope 7.2Vpp then about 2.6Vrms on RCA output, at 99 volume.
Effectively, about 15.2Vpp then about 5.4Vrms on XLR.

 

[DarkStar73]

I've had the DAC for a day and it sounds great, but I think I received a defective unit. Just noticed nothing was coming out of the right channel. Checked all the connections and all good there. Resetting the DAC fixed the issue. Anybody else experienced this?

The issue just happened again. Had the reset the DAC to get sound out of the right channel. I will be sending it back and getting a replacement.

 

[ninetylol]

Btw anyone noticed Shenzhen Audio dissappeared on Amazon? No way to order the SU-9 now from europe. (and I will never order from China)

 

[DarkStar73]

Btw anyone noticed Shenzhen Audio dissappeared on Amazon? No way to order the SU-9 now from europe. (and I will never order from China)

They are still on Amazon. I've got a replacement delivering on the 6th because the one I got on Sunday has an issue with no sound out of the right channel. A reset fixes the issue, but for $459 I expect things to work properly!!

 

[ninetylol]

They are still on Amazon. I've got a replacement delivering on the 6th because the one I got on Sunday has an issue with no sound out of the right channel. A reset fixes the issue but for $459, I expect things to work properly!!

I dont see them offer any items (EU Amazon that is)

 

[Moderate Dionysianism]

No way to order the SU-9 now from europe.

https://www.audiophonics.fr/en/dac-...tooth-50-mqa-32bit-768khz-dsd512-p-14801.html

 

[gew55]

2 months ago I planned to replace my UMC-1 Emotiva with something better. But after a lot of reading on this website and the advice of Amirm, made the decision to purchase this SU-9. The most I have in music are cd's. Those can be played through this amazing DAC converter. Okay my conclusion is, the DAC inside the emotiva isn't really that bad. But with this small amount of money, this really is a great upgrade. More space, more punch, really beautiful. And for the True-hd master blurays the emotiva will do perfectly
Spotify also sounds great on the Bluetooth at 96 KHz hi-res, easy to discover new music. But really buy the cd in a good player throughout this DAC