This is a review and detailed measurements of the Singxer SU-1 USB to S/PDIF, AES/EBU, and I²S Audio Bridge (converter). It is on kind loan from a member. I think the SU-1 was released back in 2016. I hear a lot about it so I am happy to have one to review now. Looking on Amazon, the SU-1 costs USD $400 including Amazon shipping. This is a lot of money to pay in this day and age when USB is built into just about every modern DAC. To use it then, it better far outperform native USB interface on DACs as many people believe.
Other than somewhat fancier feet, there is nothing to distinguish the SU-1 from countless other products from China. Here, you see it in the middle of the stack of gear I used to test it:
There is nothing to select so not much to say as far as usability. The unit was was plug-and-play in Windows without the need for any driver.
The backside shows nice set of output connectors with notable absence of Toslink optical:
It is nice to see S/PDIF both in BNC and RCA forms. AES output (XLR) is nice because it is balanced and may help ground loops if your DAC has the same input. Can't imagine anyone using the master clock/word output in consumer arena but it is there nevertheless.
As you see, there is an IEC mains socket indicating the power supply is internal. It is a linear affair so not sure why the person who sold it to the member who is loaning it to me, and re-wired it for external power supply input. It was a very clean mod so I just reversed it to AC so that I could test it as others are using it.
Measurements
The ultimate test of all of these tweaks is whether the analog waveform -- the thing we hear -- out of a DAC is changed. So put the recently reviewed Gustard DAC-X26 DAC on the bench, aiming to compare its output using native USB or through SU-1. Here is the native USB input performance on our usual dashboard:
We have seen this before so let's route the USB through Singxer SU-1 and then into S/PDIF input of Gustard DAC-X26:
Absolutely nothing is changed other than run to run variation.
Let's get more critical and run the j-test jitter and noise on the DAC again using native USB and through Singxer SU-1:
There are a few spikes here and there in both instances. All of them are below 120 dB which means they are provably inaudible.
So as far as Gustard DAC-X26 is concerned, it has no need whatsoever for the SU-1.
But maybe there are other goodies not seen with this DAC so let's analyzer the digital S/PDIF signal itself. First graph is comparison of my Audio Precision analyzer looping back onto itself versus receiving the same bits through USB/Singxer SU-1. What is being shown is the spectrum of jitter while playing the J-test signal (as above):
Ideal graph here would be below the bottom with no spikes whatsoever. The world is not ideal so even my expensive analyzer has data dependent jitter. We see spikes correlating with 12 kHz which is the main frequency of J-test (in green).
Looping through Singxer SU-1 (in red) makes matters far worse. The tight spikes are the embedded 250 hz square wave in j-test signal. Their existence here means that jitter is created in SU-1 due to data that it is processing.
Now, you may say that my analyzer better be better. So let's even out the playground by comparing the SU-1 to Gustard U12 USB to S/PDIF converter I bought a year ago but have not had time to review. Here is how the two battle it out:
The SU-1 is the same as before in red. The spikes in blue are from Gustard U12. Other than a few more spikes below 1 kHz, the magnitude of the spikes are much lower in Gustard U12. The U12 costs around half as much at USD $170.
Conclusions
As we know intuitively, a well designed DAC whose performance is measured objectively, is of no need to external tweaks. If it comes with a USB input and I show it to have good performance, that is that. Don't chase ghosts with such external measures as Singxer SU-1.
High performance DACs push my analyzer to the limit. As such, I expect a $400 USB to S/PDIF converter to do the same. That is not the case here. The SU-1 output is quite a bit dirtier than my analyzer output.
Comparison to Gustard U12 also shows that the SU-1 is nothing to write home about. The SU-1 clearly has more noise and jitter than it should.
Needless to say, I see no reason whatsoever to recommend the Singxer SU-1. If you have an older DAC without USB input, opt for cheaper options like the Gustard U12 or a few others I have tested. Heck, for half as much you can get a S/PDIF converter running on a Raspberry Pi such as Allo Gigione and get streaming option for free!
------------
As always, questions, comments, recommendations, etc. are welcome.
Look, some people want happiness. I just want more money so I can buy it for them. Please donate using:
Patreon: https://www.patreon.com/audiosciencereview), or
upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
Other than somewhat fancier feet, there is nothing to distinguish the SU-1 from countless other products from China. Here, you see it in the middle of the stack of gear I used to test it:
There is nothing to select so not much to say as far as usability. The unit was was plug-and-play in Windows without the need for any driver.
The backside shows nice set of output connectors with notable absence of Toslink optical:
It is nice to see S/PDIF both in BNC and RCA forms. AES output (XLR) is nice because it is balanced and may help ground loops if your DAC has the same input. Can't imagine anyone using the master clock/word output in consumer arena but it is there nevertheless.
As you see, there is an IEC mains socket indicating the power supply is internal. It is a linear affair so not sure why the person who sold it to the member who is loaning it to me, and re-wired it for external power supply input. It was a very clean mod so I just reversed it to AC so that I could test it as others are using it.
Measurements
The ultimate test of all of these tweaks is whether the analog waveform -- the thing we hear -- out of a DAC is changed. So put the recently reviewed Gustard DAC-X26 DAC on the bench, aiming to compare its output using native USB or through SU-1. Here is the native USB input performance on our usual dashboard:
We have seen this before so let's route the USB through Singxer SU-1 and then into S/PDIF input of Gustard DAC-X26:
Absolutely nothing is changed other than run to run variation.
Let's get more critical and run the j-test jitter and noise on the DAC again using native USB and through Singxer SU-1:
There are a few spikes here and there in both instances. All of them are below 120 dB which means they are provably inaudible.
So as far as Gustard DAC-X26 is concerned, it has no need whatsoever for the SU-1.
But maybe there are other goodies not seen with this DAC so let's analyzer the digital S/PDIF signal itself. First graph is comparison of my Audio Precision analyzer looping back onto itself versus receiving the same bits through USB/Singxer SU-1. What is being shown is the spectrum of jitter while playing the J-test signal (as above):
Ideal graph here would be below the bottom with no spikes whatsoever. The world is not ideal so even my expensive analyzer has data dependent jitter. We see spikes correlating with 12 kHz which is the main frequency of J-test (in green).
Looping through Singxer SU-1 (in red) makes matters far worse. The tight spikes are the embedded 250 hz square wave in j-test signal. Their existence here means that jitter is created in SU-1 due to data that it is processing.
Now, you may say that my analyzer better be better. So let's even out the playground by comparing the SU-1 to Gustard U12 USB to S/PDIF converter I bought a year ago but have not had time to review. Here is how the two battle it out:
The SU-1 is the same as before in red. The spikes in blue are from Gustard U12. Other than a few more spikes below 1 kHz, the magnitude of the spikes are much lower in Gustard U12. The U12 costs around half as much at USD $170.
Conclusions
As we know intuitively, a well designed DAC whose performance is measured objectively, is of no need to external tweaks. If it comes with a USB input and I show it to have good performance, that is that. Don't chase ghosts with such external measures as Singxer SU-1.
High performance DACs push my analyzer to the limit. As such, I expect a $400 USB to S/PDIF converter to do the same. That is not the case here. The SU-1 output is quite a bit dirtier than my analyzer output.
Comparison to Gustard U12 also shows that the SU-1 is nothing to write home about. The SU-1 clearly has more noise and jitter than it should.
Needless to say, I see no reason whatsoever to recommend the Singxer SU-1. If you have an older DAC without USB input, opt for cheaper options like the Gustard U12 or a few others I have tested. Heck, for half as much you can get a S/PDIF converter running on a Raspberry Pi such as Allo Gigione and get streaming option for free!
------------
As always, questions, comments, recommendations, etc. are welcome.
Look, some people want happiness. I just want more money so I can buy it for them. Please donate using:
Patreon: https://www.patreon.com/audiosciencereview), or
upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).