I got my hands on the Singxer SU-6 in 2020. 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 was still strong, 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 awesome experience. The Singxer SU-6 usb audio interface was noticeably more transparent and neutral.

At resolution, instrument separation, soundstage, and bass quality and depth, the Singxer SU-6 usb audio interface showed its excellence and in a way, beat out the Matrix X-SPDIF 2 in the criterion mentioned; a more neutral take. However, the Matrix X-SPDIF 2 is no slouch, at all, in these criteria.

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 its 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, and I got this impression with the Matrix X-SPDIF 2 as well.

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 transparent and spacious rendering. The depth is definitely noteworthy and there it feels that you’re listening to something that is HiFi.

It really depends on your listening preferences if that the Singxer SU-6 usb audio interface is worth the upgrade over the Matrix X-SPDIF 2. 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 difference is between the slight warmth of the Matrix X-SPDIF 2, and a bit more transparency and openness in the Singxer SU-6. The Matrix X-SPDIF 2 has a slight bloom and unique energy to the notes, whereas the Singxer SU-6 offers a cleaner and more spacious sound for the musical details to captivate. In the end, I think if anyone wants to experience a slightly warmer sound signature that is more romantic in the sense that, the notes are slightly more extended with a certain softness to them, the Matrix X-SPDIF 2 is an excellent option.

I still wholeheartedly recommend the Matrix X-SPDIF 2. The Matrix X-SPDIF 2 still remains great in its own right, again, it’s the slight warmth versus more transparency and depth. In a sense, the Matrix-SPDIF 2 may be more fun and perhaps more engaging to listen to because the sound is slightly wetter, giving it a certain alluring, magic quality to the sound by comparison to the Singxer SU-6.

Would it make a difference if all you’ve ever heard was the Matrix X-SPDIF 2? All you would have to do is imagine a Matrix X-SPDIF 2, an already excellent product, with the Singxer SU-6's more transparency, instrument separation, and deeper hitting bass. The Matrix X-SPDIF 2 is not inferior by any means, it has strengths that the Singxer SU-6 does not, and vice versa. It's fun to switch them out. I would say that the X-SPDIF 2 is for a listener who knows what they want, it's an elegant and welcoming-sounding USB audio bridge; it is certainly special and worth owning alongside the Singxer SU-6. I have both and intend to keep them, as they both cater to my listening preferences.

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. 

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