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
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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.
Thanks!
Hello,
@Delta9K,
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.
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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.
Findings
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! 
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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.
Hello there! Wanted to ask, how are you liking the KTE version? (I was recently recommended picking up an SU-2 or SU-6 for my chain, so I figured I’d ask!)
Guys, need some help please. Just got my Sda2c now and downloaded the driver from singxers web page, but windows doesn’t recognize it…any thoughts?
Hello,
Try a another USB port.
Which version of the driver file did you use?
The current version should be Audio Usb 5.12.
And if it has been installed, there should be an icon with Usb Class in the bottom right-hand corner of the taskbar when you restart the computer.
Then switch on the Sd2 and it should work.
Otherwise, click on the speaker symbol and see if the output is selected correctly.
It may be that it has not yet been selected and you need to change it.
Looks like @GoldenOne posted some measurements of the SU-2 KTE! Re-posting here in case others are interested, and also because I own an SU-2 KTE and purchase validation is a thing 
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Hello,
If you only use it for streaming and cd applications, the normal Su2 will be quite sufficient in my opinion.
I think it only makes sense if you really have studio applications where it makes sense.
I think the test shows that it is clearly better after the mod than the Su 2 and Su 6.
If anything it would be interesting to see the difference between the normal Su 2 version and the tuned version.
I’m almost sure the normal version is not too far off, so not even 50% better.
Spending 600$/€ more for theoretical measurements and changing some coefficients is a bit much even if it is up to everyone.
I recently connected the Su 2 to the Little Dot Dac 1.
There was not much difference.
It gave a little more smoothing, a little more treble and a little better 3D texture.
Considering that this Dac was created in 2008/09, the implementation and components available at the time only goes to show how good a Dac can be when the
implementation is right.
Where I noticed the biggest leap and improvements was with the Denon 800ne.
When I leave the room and stand in the kitchen I can still hear the clear voices and instruments vibrating.
On the Sda 2c, even now after well over half a year of use in the combination, the improvement was not quite as clear as on the Denon much more present.
So a small improvement is still borderline for the price.
A small increase in all areas and 3D representation.
Where the Su 2 is obviously really good is with poorly designed hi-fi stereo amplifiers with a less good Dac or amplifiers that don’t have one like the vintage amplifiers from the 80/90s.
Provided it supports an analogue input.
And of course really bad usb implementation of the dac.
On the Little Dot Dac 1 which only supports Usb 16/44 versus coax, coax was slightly better but the Usb port wasn’t even bad even if it was limited.
So all quite sublime in my perception.
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Thank you for your video.
You addressed everything that needed to be addressed, thank you.
There were two points I missed.
Under Su2 it would have made sense to explain and mention the dip switches.
That you also have to set them depending on the Dac.
The second point you mentioned towards the end was whether it would be worthwhile to compare Modius and Bitfrost.
1000$/€ for Bitfrost and Su 2 is a bit much, that’s true, because you can probably get better for the money.
In the meantime I have personally connected the Little Dot Dac 1 which came out at the end of 2010 with the Su2 via Coax.
The dip switch position was the same as on the Sda 2.
My impression of the combination was that the sound quality was subtly better.
I can well imagine that the Su 2 makes sense with a less well thought out implementation of the Dac.
Like the Modius, for example.
Which more or less clearly represents that.
The fact that I personally didn’t get the impression that the Little Dot dac 1 makes a huge leap in combination shows that the implementation is quite good and quite close to the SDA 2 and that we are talking about a good 8 years difference in time and that there weren’t the electrical components then that there are now, or at the time the SDA 2 came out, roughly taken as a personal reference.
It really seems to depend more on the implementation.
But there are still alternatives, especially if you only need a coax connection, the F1 from Singxer might be interesting, if you don’t want to pay the full price of the Su 2 or even Su 6 unit.
Not to be underestimated is the possibility of an I2S connection if the Dac supports it, and of course a relatively clean USB signal.
The audio industry could build a galvanically isolated usb signal into the dac with relatively little effort for maybe 10$/€ more.
That would be worth paying for.
It would be also predominantly most of the things already on board,power supply ect…
If you look at the switch boxes like the Singxer F1 it is quite primitive and effectively done.
But for just under 200-170$/€ I am scratching my head a bit.
Let’s briefly return to the Little Dot Dac 1, which has an outdated usb port that outputs a maximum of 16/48.
Compared to the su2 via coax where 24/192 is feasible.
The usb port of the Little Dot was hardly worse and even doubt a bit the added value and price for a Singxer F1 box as an upgrade.
It really makes sense if you have an obsolete port and could spend more via coax.
If you have the file or the streaming provider offers it.
Qubozz is currently still quite open in this matter with Hi res 24/192.
But most of them share 16/48 for the most part.
Mqa makes no sense for Tidal with the outdated technology of the Dac, as it is not Mqa-capable in order to be able to listen to 24/96.
So yes, somewhere towards the end of the video I have to agree with you that it is a bit difficult.
But nevertheless, such a box is always a nice to have, pragmatically speaking.
For those who still have an I2S input on the Dac, I found the added value definitely audible and obvious.
You won’t be disappointed, but it’s not a huge leap either.
Yes @WaveTheory , nice job on the video. While I certainly appreciate the device and what it does, I found that the device I am currently using does a pretty fine job and allows me to feed my Frost via coax, which let me tell ya is damned good. It does this at considerable savings over the SU-2.
I suppose if my system were next level I would look at this unit. For my setup, however, the U2 Pro is just right.
I know this is Su-2 thread but I have a Su-6 question. Does anybody know if this is ok to watch videos with? I.e. latency, audio and video in sync?
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Hello,
good question.
I think that the quality of audio reproduction is improving.
Cleaner, deeper etc…
But something like a better picture reproduction would not be technically possible.
I hope that answers your question.
Sorry for my poorly worded question. For example Denafrips ddc’s have large latency’s which causes audio and video to be out of sync. I was wondering if Singxer Su-6 would have the same problem or not.
Cheers.
Hello,
no, I don’t think that will be the case.
As a Su 2 owner, I don’t have these problems on the PC.
Not even on Youtube when I watch something.
I would just try it if there are any doubts, it can only go wrong if it is not good :-).