I got my hands on the Singxer SU-6 last year. If anyone has seen the review I did on the Matrix X-SPDIF 2, they would know exactly how I feel about USB audio interface reclockers. 

The Singxer SU-6 usb audio interface is a device I had interest in after looking at competitors in the market that provided “clean” USB audio to the chain. Among the contestants were the Matrix X-SPDIF 2, and the Audio-GD DI-20HE. 

Superseding the Singxer SU-1, the Singxer SU-6 is a bit more expensive than the Matrix X-SPDIF 2, coming in at $690, whereas the latter is priced at $399.

The Singxer SU-6 usb audio digital interface is a new generation of high-performance USB audio. It uses XMOS’ latest xCORE-200 series and Xilinx’s high-performance large-scale PGA chip, along with a thermostat-level clock system.

Crystek’s two CCHD-957 femtosecond crystal oscillators provide the foundation for the superior audio signal quality of the Singxer SU-6 usb audio interface output.

The Singxer SU-6 usb audio interface uses a standard USB 2.0 input and has plentiful outputs, including SPDIF for fiber/coaxial RCA and BNC outputs, AES/EBU for XLR balanced output, RJ45, HDMI. It also has an I2S output (including DSD ON signal), and its clock output supports MCLK main clock and WCLK word clock, all powered and optimized for audio with a 7.5F supercapacitor.

The Singxer SU-6 usb audio interface is a unique animal, it’s build quality is not as refined as the Matrix X-SPDIF 2, but it remains of great quality with more display options, showing when the usb audio interface is playing audio and even when it is playing DSD.

With any upgrade, I’m always skeptical on whether the audio equipment will bring about any changes. With the Singxer SU-6 usb audio interface, my skepticism upheld, and I didn’t think another usb audio interface would bring about any significant change.

I was pleasantly surprised upon my first listen of the Singxer SU-6 usb audio interface. Comparing the Singxer SU-6 usb audio interface to the Matrix X-SPDIF 2 was an enlightening experience. The Singxer SU-6 usb audio interface was noticeably more transparent and neutral.

At resolution, instrument separation, holographic presentation, soundstage, and bass quality and depth, the Singxer SU-6 usb audio interface showed its excellence and beat out the Matrix X-SPDIF 2.

Some notable differences was that the Matrix X-SPDIF 2 provided more bass quantity, extension, and a warmer signature. 

The Singxer SU-6 usb audio interface provided a more cleaner, quality bass that extended deeper than the former, which could be considered an added nuance considering it’s more neutral nature. 

Plugging in the Singxer SU-6 usb audio interface for the first time is like plugging in a whole different DAC altogether. I got this impression with the Matrix X-SPDIF 2 the first time as well, but it was to a bit of a higher degree with the Singxer SU-6 usb audio interface.

One could assert: if USB power was implemented correctly, there wouldn’t be a need for such a device. And it’s true. However, it seems there’s a place in the market for everybody, and we can’t hold DAC companies accountable for not having expertise in USB audio conversion.

As a direct comparison to the Matrix X-SPDIF 2: the soundstage opens up a bit more, the bass reaches deeper frequencies, the mids sound more pronounced, and there is a sense of a more faithful rendering. The depth is definitely noteworthy and there it feels that you’re listening to something that is HiFi.

It is difficult to say that the Singxer SU-6 usb audio interface is worth the upgrade over the Matrix X-SPDIF 2. There is a certain transparency that the Singxer SU-6 provides that the Matrix X-SPDIF 2, which, while is great in it’s rendering, is not quite on the same level.

As in my review of the Matrix X-SPDIF 2, I noted that “There is a complete sense of transparency in the delivery, and, in a word, it sounds clean.” The Singxer SU-6 usb audio interface offers this, and it’s surely, from my subjective listening tests, a step up. It feels like the soundstage is given a definitive space for the musical details to shine.

The difference is between the warmth of the Matrix X-SPDIF 2 and the transparency of the Singxer SU-6 usb audio interface. The Matrix X-SPDIF offers a transparent sound, but the Singxer SU-6 offers an even cleaner, more dynamic sound. In the end, I think if anyone wants to experience a warmer sound signature that can go reach higher volumes without fatiguing, the Matrix X-SPDIF 2 would be the way to go.

On a budget, I would still wholeheartedly recommend the Matrix X-SPDIF 2. However, after hearing the Singxer SU-6 usb audio interface, if I had an option to choose honestly - it’d be both! The Matrix X-SPDIF 2 still remains great in its own right, again, it’s the warmth versus more transparency and depth. In a sense, the Matrix-SPDIF 2 may be more fun to listen to, because not all of us want the transparency rendering all the time.

Would it make a difference if all you’ve ever heard was the Matrix X-SPDIF 2? I think the answer to that is easier than one might think. All you would have to do is imagine a Matrix X-SPDIF 2, an already good product, with more transparency, instrument separation, and deeper hitting bass.

I would highly recommend the Singxer SU-6 or Matrix X-SPDIF 2 to anyone looking to upgrade their audio chain. They are both worth the price because it offers a clean USB signal to DAC’s that aren’t technologically advanced with USB technology. 

As an audiophile myself, I think the worth of devices like the Singxer SU-6 and Matrix X-SPDIF 2 especially becomes apparent when considering just how many DACs exist, and how often we will be experimenting and upgrading our gear. The Singxer SU-6 and Matrix X-SPDIF 2 would take each DAC and play it to its fullest potential, which is the real value behind usb audio interfaces.

Product Links:

Singxer SU-6: https://amzn.to/2Yk6EcG

Matrix X-SPDIF 2: https://amzn.to/3l41El6