Singxer SU-2 DDC

@db_Cooper @Tommy @FBizzle

Here we are again at the small rewiev of the famous Singxer SU 2 that is always doing the rounds in the scene.
Mainly because of its i2S option and jitter reduction.

Reason for purchase:
Since I’ve had the Singxer Sda 2 C for a long time, I’ve always been itching for the I2S output.
Again, a bit more performance and so on. Of course, also the curiosity of the not too well known/spoiled I2S output.

To describe Singxer in a few Words:
What does Singxer do? And what is Singxer?

Singxer, like Matrix Audio, has moved to a digital-only platform to play music in the digital realm.
And they perhaps distinguish themselves from wanting to become mainstream.
Their products offer a very reasonable quality that remains at an affordable level, and also have quite a fine nose for making music sound good.
If I had to rate my Matrix Audio Ipro Mini 2 purely as a headphone section.
I have to say it sounds too cold and doesn’t pick me up, even when I connect another amp.
This is totally different with the Singxer in the headphone picks me up,sounds musical to me.warm,powerful,the heart is there.

On the stereo system, the Marix Audio Dac is definitely the measure of all things in my home and I haven’t heard anything better yet.
So it’s the other way round and I love the Matrix audio.

And I’ve stuck with the Sda 2 C in the meantime and don’t want anything else.
No matter how great the latest Dac is, it leaves me cold.
The Sda 2 C was exactly what I was looking for after 2 years of “searching”. I love it somewhere and after 9 months I still have a lot of fun with it.
I still have a lot of fun with it.

Now for the “upgrade” SU 2 from Singxer.

What can I say? As with the SDA 2 C, there is nothing to say about the manufacturing.

Everything is firmly sorted in its place and at a level you can only dream of.
I can’t find anything wrong with it.
As a tip I can only say and give, check the fuse of the device.
Replace it if necessary.
I have personally used the Hifi Tuning supreme 3, the golden one, in the SDA 2 and have also tried the silver one, but I liked the golden one better.
But it’s not necessarily a must.
The performance was moderate but audible and quickly forgotten.


I used the Pangea cable for the Hdmi, the Inakustik Usb cable for the Usb cable and a simple, affordable shielded cable for the power connection.
The fuse has remained original, the current driver has been downloaded from the Singxer homepage.
The information comes directly from Singxer itself for use with the SDA 2.

Su 2 : SW3/6/7 is ON, others are OFF

With the SDA 2, if you have it, SW3/5/6/8 is ON, others are OFF.

I am writing this down because I have not found a single review on how to set what on the Su 2.
The Singxer Su 2 is set to allow the external clock to work, if I understand correctly.

Source: Pc connected to Matrix Audio Element H Usb card to Su 2,power supply used separately for the Element H.
Software: Audirvana 32Bit/96 Khz
Hardware: Singxer SDA 2 C, DBX 1215 Eq and Feliks Euforia Tubeamp.Headphones: Audeze Lcd 2 C due to its superb unsparing resolution.

I will make two different statements in advance between the two amps.
Because I noticed two three things.

Burn in:
After plugging it in, I didn’t notice anything directly explosive.
The main reason I blame is my Matrix Audio Element H card…
The card is almost worth it if you only connect one dac/amp.

After a few hours of running and sitting down with the I2S connection, passages shimmer through where you think oh wow.
That’s why I give it 20-30 hours of play-in time, just like the Sda 2, to get it out of my head and eliminate it.

First sound impression:
Nothing that blew me away at first.
While listening and thinking, I thought I’d unplug the headphones from the Feliks Euforia and connect them directly to the Sda 2.
What can I say about the Feliks, my first assumption was correct that it was still masking despite the fact that an Eq is connected.
I still blame the tubes or it is really due to my Eq setting which goes from the SDA2 to the Eq and then to the Feliks.
I’ll explain what I suspect in a moment.
Directly connected to the SDA2 there is definitely a bit more pressure, more depth, a bit more separation, it feels fun.
I will do another A/B test with Su 2 and without.

Back to the Feliks:
Since the connection from the PC to the Dac or Su 2 can be considered clean, even with I2S, the Eq probably needs to be readjusted because the music playback has become even more
more precise and therefore masked.
Or also that the “actual clean signal” is transported to the dirty signal starting with the Eq up to the Feliks. Or the signal chain is too long so that something is lost.
Even if the cables are relatively short, I don’t use cables with a maximum length of 1 metre.
On Saturday I got new driver tubes that are still burning in.
It is possible that this is also the reason.

In the meantime I have made an A/B test between both Singxer devices.Once with Su 2 once without. And the play-in time is also over from Su 2.

Without Su2 Sda 2C connected via Usb:
The bass is a little more powerful, but does not reach all the way to the back. Mids and highs are normal.The shining is there and warm.
The resolution and attacks are there. The description of how the Sda 2 C was rated are trustworthy.

With the Su2 via I2s connection:
The bass is a little less punchy than the Sda 2 but reaches all the way through to the rear and is even more recognisable in place. The mids and highs reach all the way through from the beginning to the rear.
The stage radiates a little more than without the Su2. The localisation is even better with the instruments. I would say it has really become more 3 dimensional than without the Su2.
than without Su2. This is very noticeable with a piano and violin instruments that are present under the mix. (Frontin from Pharell Willams Feat.Jay Z is a very good example of this).
The Su 2 doesn’t really colour anything up and stays musical, it doesn’t play overly exciting or unexciting, I’d say it’s somewhere in between.
Like the Sda 2, it invites us to listen and enjoy music.
The resolution has definitely increased again. When recording live, I’m standing in front of the stage almost live in the scenery.
All in all, the Audeze Lcd 2 has also improved in the hiphop area, although that’s not really its domain. And it’s fun, especially because I always found the bass a bit thin.
Now, with the Su 2, it’s not any more, it’s really crisp and authentic with a good punch.

Su 2 with Feliks Euforia:
As already mentioned, I changed the driver tubes at the weekend.
In order to get everything halfway oneway.
With the Ps Vane tubes I found the sound too neutral. With the Lin lai tubes it changed again.
That’s why it’s a bit difficult to say what has improved where, and it still needs a bit of time.
I disconnected the equalizer completely and used the direct Rca output from the Sda 2 to the Feliks Euforia.
Even though I can switch off the bypass, I wanted to know more about it. I also wanted to create the shortest signal path and minimise the loss through the analogue path.
The signal that actually goes through the Eq then goes to the Euforia.

I found out that it also makes sense to connect the Su 2 to a tube amplifier.
My own impression is that by changing the tubes and adding the Su 2, the bass has increased again compared to the Ps Vane tubes which are relatively neutral.
With the Audeze it was a torture because the bass was relatively bloodless, but not any more, which is why I added the Eq.
Now that the Eq is gone, the sound impressions are similar to those described above with the Su 2 and Sda 2. The separations are a bit better, also more explosive and direct.
But that can also come from different power tubes, which also have an influence on it, I currently have a set of re-labelled Sylvania 6080 in it, which arrived at the same time on Saturday.
But all in all it makes sense I would say.

Technical side:
My impression is that the Su 2 only makes sense when the output device is connected directly.
For example, I2S out to I2S in, coax out to coax in to the stereo system, where the effect is certainly clearest and makes the most sense.
What is not advantageous is if the output of the Su2 is used to the Dac and then looped to another source device or through an Eq as was the case with me or something similar.
And then it goes to the amplifier.
My recommendation would be to use the outputs on the Su2 directly. It is important to set the jumpers on the underside of the Su2.
But at most use the output of the Su2 as described above to the Dac and at most to the tube amplifier, or stereo system via XLR or RCA.
If you want to use the coax out of the Su 2, I think you have to adjust another jumper.

Is it worth the money?

Yes, if you have the connections that your Dac or stereo amplifier supports, such as I2S, coax, it is worth considering. It also makes sense if you cannot use I2S.
Then use the coax connection or Aes, especially if you want to be flexible.
It would make sense to use it instead of the more expensive Matrix Audio Element H Usb card, which only makes sense with a separate power supply.
The card reduces the jitter and relieves the processor, but it also does a very good job.
As a tip I can give a separate Pci Usb 2-3 card to the Pc to plug and the rest of the Su 2 to make that is more than sufficient.
Since the price of the card has risen, plus a separate power supply, you are well above the price of the Singxer Su 2.

Conclusion: On the whole, the Su 2 is an was not a bad buy.will I keep it? Hell yes.
I thought when I first heard about I2S and read an impression of ASR that it would be a wash.
Now that I’ve tried it myself, I have a different impression of it.It definitely does something to the sound.It makes it smoother,smoother.Not quite as syrupy as a tube amp.
but it goes in that direction.
One regret I have is that I doubted myself and waited too long.


Enjoyed your take on the SU-2. I will be using the SU-6 once my speakers come in. Chain will be PC > Matrix Element H > SU-6 > Coax > Parasound P6. I noticed when researching the SU-6, some people over at Head-Fi stated that the USB to I2S connection is not isolated and they share a ground. The USB to Coax connection is isolated however. One guy even took a Dremel to his PCB to physically sever the connection to make the I2S isolated. You can also use Kapton tape to isolate instead. I think I recall them saying the SU-1 and/or SU-2 operated the same way. Something you can play around with if you want to.

EDIT: Found the thread:

You will also find right below that topic, pictures of filling an SU-6 with sand to improve sound. Feel free to try that too lol

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I’m glad you liked the article.
I took a look at it on Head fi.
I didn’t find what you mean on the Su 2.
There is definitely nothing there.
I would have heard it because I listened a bit with the Euforia before, the background is free, even on the Sda2 when I plugged it in, there was nothing when I paused the song.

It seems to only affect the Su6.
The solution is actually OK, you can do it.
But if this were the case for the Su6, the responsibility lies with Singxer and not with the customer.

I would ask Singxer if this has been fixed before buying it, because as a customer I don’t have to tinker with it.:v:

Well, I’ll leave it at that whether you really have to fill it with sand.
If you look at it closely, it makes very little sense, because sooner or later the foil can burn a hole in it and then what?:see_no_evil:
And what advantage it should bring in the end is also a mystery to me.
I have nothing against tuning, but it doesn’t have to be like that. Some people get strange ideas.:grin:
If it did, our audio equipment would probably be 1-2 kg heavier or more, depending on the size.

Found it on page 32:

"Singxer’s main selling points are the ground isolation and reclocking, but that is also their biggest blunder, Singxer left the USB metal shield and HDMI metal shield connected, this is a backdoor for noise from the noisy PC/USB side and this caused endless issues with my LKS.

The fix is to get a device like the Wyred 4 Sound Recovery that breaks USB ground.

Bottom line is get the SU-6 if you have the budget, SU-2 if not.
Its true competitors as DDC for your DAC are much more expensive (AudioGD, Denafrips etc)

Singxer boxes are far from perfect, the shield blunder means it needed another isolator to properly handle its ground isolator function, more complexity, more cost.
Singxer has room to improve here especially on the 700USD SU-6"


I think the shared connection for USB and I2S applies to most of the SU-X units. You should be able to verify with a multimeter if you have one. Since you are using the Element H that should help a lot though.

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Hmm yes the Wyred 4 Sound Recovery would certainly be an alternative to the Element H card according to the description.
You probably won’t go wrong with it. That’s a very good tip.:wink:

As you said, it’s conceivable that the Element H could counteract this.
I can only say that it runs very well with the Su 2 and so far I have not noticed anything negative.
I am free of the hum on my chain with the Su 2.

I was also interested in the Su 6 and had a look at the circuit board and the connections.
I liked the Su 2 better in terms of the connections.
Because I would still like to try to go in via coax to the stereo system.
Since the Denon 800NE supports digital input.:see_no_evil:

Furthermore, I found more negative things about the Su6 than about the Su2.
There is also a mod for the Su 2, but I personally don’t want to use it.
To be honest, it’s too expensive for me.
Even if it would make another leap.
I’m sure you can find something better somewhere for more money.
But for what I hear, the setup is enough for me.

I’ve probably found the right tubes for the Euforia, and I’m getting a tube amp from a manufacturer this week to test.
Let’s see if it will surpass the Feliks or if it will stay with the Feliks.
Otherwise, Mcintosh mha200 or the Decware are more interesting for me in the foreseeable future.:hugs:

I don’t think the Su2 is necessarily wrong for I2s. Another option would be Matrix Audio spidf 2, maybe even the better one. Only thing Matrix Audio has a bit of a tendency to make the sound neutral and cold.
With the Element H I lost a bit of warmness but other things sounded better.
With the Su 2, mine has returned a bit and now plays sharper than the Sda 2 alone without Su 2 and Usb card.
More will probably not work unless you spend more money on an “even better Dac” I guess.

I’m all in on the bridge philosophy even for locally connected device. There’s always going to be exception but from my experience so far the quickest way to a clean source signal out of a PC is to not get your source signal from a PC in the first place.

USB from a PC has always been inferior for me. I’m sure plunking some cash into a specialized PCI card like a Matrix Element H would help, but right now feeding USB into a Yggy (with the Unisom USB interface) is still inferior to using AES from a Pi2AES running as a bridge on my desktop. I was wondering how your Singxer SU 2 would do and I’m sure it’s an improvement but I am willing to bet that if you u sed it as a network bridge you’d get the best audio from it despite the cabling you use to connect it to your DAC. It seems like a good product that fils the PERFECT price point.

I’ve done some testing now comparing now my SOtM SMS-200 Ultra Neo Special Edition… Sheesh that’s a long name. And as much as I love the Pi2AES, the SOtM is a step above as well it should be for it being about 9 times the cost. It’s not too drastic of a difference which speaks volumes about the Pi2AES but the SOtM is mo’ better in every detail

What’s interesting is that it’s NOT the USB connectivity itself that’s at issue, since the SOtM is USB out only, but the difference it that there’s no PC involved.

BTW just as a knowledge share with the community here. I sprung for one of the new ifi Power Elite power supplies to feed the SOtM and it’s expensive but it was a step up from the generic 12v LPS I was using previously.

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TLDR, from my evaluation of it, I have a positive opinion of what the SU-2 does. It has proved its value in my chain, particularly because I have a DAC that requires it.

The main reason why I chose the Singxer SU-2 over other DDCs, is that it had that native outputs that is supported by my 3 DACs. I currently use the SU-2’s AES, BNC, and SPDIF outputs at the same time. So my experience with the SU-2, (and I’m sure I’d get similar results with almost any other DDC) has been extremely positive so far. Tho I would have got by with the Matrix X SPDIF if I used optical.

I used to go from PC via USB directly to my DACs. My current DACs are the built-in DAC in a Violectric V590 amp/dac, LampizatOr Amber 3, most recently an Alpha DAC Series 2 via Optical.

My Alpha DAC essentially forced my move towards using a DDC. The short time I had the Alpha DAC connected to optical, it gave me a sense of what it could do, but I didn’t think I would be happy with it long-term. Once I added the DDC to the chain, that ‘black background’ buzzword became very apparent and I didn’t hear any other artifacts that got in the way of the music. I could go on, but sufficiently to say, optical is not ideal for that particular DAC and USB is NOT available. I use this DAC connected with the BNC output of the SU-2.

The most improved DAC is my AKM 4490 internal DAC of the V590. I was ‘figuratively’ shocked that this was the same DAC and I have to recheck multiple times that it was set as output. Using USB, the dac is fine and tuned perfectly for the amp, however the highs can get sharp and overall I consider it sterile. Connected via AES on SU-2, the highs are tamer, its a much fuller sound and the bass, which I feel this DAC excels in continues to kick ass, and in my opinion, can be competitive with the other DACs I’ve been pairing with my amp.

My other DAC, I re-acquired a Lamp Amber 3 succinctly because of the V590 USB performance. After hearing what I have heard with DDC, I probably wouldn’t have re-acquired one and would have rolled a different DAC. But now I have one again, I loved it on USB, and I still love it with the DDC. I haven’t made any comparisons with USB versus connected via SPDIF to the SU-2, and I probably never will. I extremely liked this DAC’s performance with DSD files, and I lose that by connecting to the DDC.

With that said, I ordered a Holo Audio Titanis active USB processor. I want to evaluate DSD/overall performance with it on the Amber 3 as well as my V590. Then see how it does with the SU-2.


This made me laugh out loud!

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It is black and matches my stuff, therefore sounds better than the silver ones


Thanks for the tip! I’ve been considering one, but not sure if it was really better than a LPS. I appreciate your comment here.

I have a 24V one on my pi2aes, and yes it’s an improvement, but literally more than doubles the cost of the pi2aes.

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Well, I find the Raspberry to be fearsomely bad for a mid range, high end audio chain.
Even if the power supply costs twice as much, I would look for something else.
For something simple and prophanes the Raspberry is okay, but nothing more.

I think Raspberry should improve or use their strengths for the essentials for which it was designed.

Of course, if you already have something at home like a Keces p3 or Fureman, you can get away with it cheapl

The Pi that’s being used, in the case of the Pi2AES is just the board/OS that allows you to put a pretty well implemented DDC on it. PI2AES - PRO AUDIO SHIELD - Pi2 Design


Hey thanks!

The timing of your post excellent. I am currently shopping for a DDC. The SingXer SU-2 and Matrix X-SPDIF 2 are at the top of my short list.

I enjoyed reading this and found it very informative.

Something that I’ve missed. Are you able to use more than one output at a time? For example, can you send signal through the coax to one device and through AES to another at the same time?
(I do not have any I2S capable devices currently.)

I should have kept reading - a question I had asked earlier was answered in this post.


Yes the signal comes out at the same time on Singxer Su 2.
I have tested this.
Coax via the stereo system and i2S via the Dac.

After a few weeks of use, I am completely satisfied with it.
I have no regrets about buying it.

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As luck would have it I recently got a Singxer SU-2 as part of a package deal with a Berkeley Alpha S2 DAC. I listened to the SU-2 and the Alpha together a lot and the combo is breathtaking. But today I spent some time playing with the SU-2 and the Chord Hugo 2 to see if I could tell what the SU-2 brings to the table on its own. I had to use the Hugo 2 because the Alpha does not have a USB input.

I connected the Hugo 2 directly to my Windows 10 PC via USB. The SU-2 connected to the PC via USB as well and I used a BNC-to-3.5 mm coaxial digital cable to go from SU-2 to Hugo 2. The point was to compare the sonic performance of USB direct-to-DAC vs using the USB bridge. I used the Vioelectric HPA-V281 as an amp (SE inputs, Hugo 2 is only SE), and my HE1000v2 and TH900 with Lawton chambers as the headphones.

Three quick caveats… i) This test is with only one DAC - the Hugo 2, generalizing from 1 piece of test gear is tough; ii) I used very basic/generic cables and they could be hot garbage; iii) I spent 2 hours this afternoon doing this so these are still going to be initial thoughts.

In general the SU-2 was cleaner sounding with blacker sonic background. The SU-2 had subtly more microdetail. The SU-2 also created a better sense of space and imaging that was very subtly more defined and more…stable(?)…that’s the best word I can come up with right now. The SU-2 brought out more texture in the sound. It also controlled the last bit sibilance that can come through on the TH900 through the Hugo 2 at times and gave the bass a touch more slam, and also more body and grunt. Overall the SU-2 created a more natural and believable sound. The delta between then two on each of the sonic attributes mentioned is very small and subtle, but add them up and there is a more natural, organic, and believable presentation through the SU-2.

I hope to come back to and play with this more in a couple weeks. I have a move coming up and will be packing and moving over the next couple weeks. It will be interesting to see what (or if) any of these thoughts change on the other side.


I’ve been getting several questions about what the Singxer SU-2 DDC does for the Schiit Bifrost 2 DAC. In my Bifrost 2 review I mentioned that it sounds best from its USB input, despite it having both coaxial and optical SPDIF inputs. This is due in large part to the quality of Schiit’s Unison USB implementation. Unison is Schiit’s in-house USB solution that cleans up some connection issues. The BF2 is the least expensive model in Schiit’s DAC lineup to include galvanic isolation with Unison USB. After my comments above stating what I heard the SU-2 do for the Chord Hugo 2, I got several questions about what might happen if I used the SU-2 with the Bifrost 2. So today, I sat down and did just that. Here’s what I found…

Test Gear

I used the Monolith Liquid Platinum (MLP) and Bottlehead Crack + Speedball (BHC; review in the works!) as the amps and used the Focal Radiance (review pending for this too!), Audeze LCD-2 prefazor revision 1, Drop + Sennheiser HD6XX, and Beyerdynamic DT880 600Ω as the headphones. I did not use my more expensive gear because I thought this test would be most useful using all mid-fi gear, as those who own and use the Bifrost 2 will most likely have other gear around that same level of technical ability; it seems the most real-world to me, anyway. The MLP was connected to the BF2 via XLR and the BHC via single-ended RCA cables. The SU-2 was connected to the coaxial spdif input of the BF2 via a basic Monoprice 75Ω coax cable and both the SU-2 and the BF2’s USB input were connected to my PC via identical and basic Monoprice USB cables.


In general, the SU-2 is a marginal technical upgrade over Unison USB. The soundstage sounds more open. This is not to say the soundstage is bigger, but there is a feeling of space beyond the soundstage that is more present with the SU-2 in the chain than just straight to Unison USB. To my ear, the left-center and right-center sonic images were also slightly more fleshed out and believable with the SU-2. The SU-2 brought out more microdetail. Even though everything was inherently volume matched because the same DAC was used and the same amp was used, I kept wanting to turn up the volume when Unison was in use. This is likely because the SU-2 was helping resolve more fine detail that was missing with Unison. The SU-2 also brought more slam and macrodynamic impact, with a more convincing representation of speed and quickness. Finally, this test gave me a better understanding of the term “tonal density”. With the SU-2, individual tones and sounds had a fuller, weightier sound to them. They didn’t sound bloated or overdone, it was more of a sense of tonal completeness than Unison was able to convey.

The above paragraph likely sounds like a blowout in the SU-2’s favor. I did not find that to be the case. The differences are always subtle. To my ear, the Radiance from the balanced headphone output of the MLP resolved these differences the most starkly. The LCD-2 from the same amp much less so. The 6XX from the BHC was probably just behind MLP + Radiance. The DT880 + BHC was probably somewhere between the LCD-2 and 6XX. The LCD-2 is a more relaxed headphone to begin with, so I suspect that is why it was most difficult to hear the differences there, though they were present. But, regardless of pairing, the differences are small. The magnitude of change is certainly less than what the SU-2 and Hugo 2 did together.

Is SU-2 Worth It For BF2?

Ugh, the question of ‘worth it?’ is so tough. There is no universal answer. If I had to my system building to do all over again and was using the BF2 as my primary DAC, knowing what I know now I would save the $429 MSRP of the SU-2, save a little longer, and look for a used Yggdrasil. A used Yggy can be found in the $1.6k-1.8k range typically. I think the jump from the $700 BF2 to that price point is larger than the jump from the $1129 total of BF2 + SU-2. However, if you have BF2 and a good deal on a used SU-2 comes along, it’s not a bad option. It is an upgrade and will pay even bigger dividends down the line if you choose to make the jump up to the next tier of DACs.

OK, I hope this helps those of you who were dying of curiosity about SU-2 + BF2. Cheers, all. Enjoy the music! :beers:


Thanks for sharing this. The timing is excellent. I am getting close to pulling the trigger on a Bifrost 2 and I was wondering this very thing about the SU-2 and whether it would be worth it. Sounds like I will be saving the money. I already have a re-clocker on my USB cable anyway which is doing a great job, so it will suffice.

Thank you @WaveTheory,

you’ve kicked things off with the usb implementation.
I agree with you there.
But that doesn’t necessarily mean that it has to be bad, depending on the dac.
As a Singxer Sda 2 user, I continue to feed it via i2S, which will certainly make a difference.

But for your conclusion, which you expressed at the end, I see the advantage rather in “for poorly implemented USB” that the Su can go one better.

Since you still have the Su 2 it might be possible to connect the SU 2 to a less good Dac to give this theory another picture?

Finally, it was as difficult for me to recognise the differences as it was for you, but in the end it makes it better.
It sometimes takes a little time, but now I only listen to the Singxer SDA 2 + SU2 combination and only enjoy it with the Feliks Euforia.