It all looked so straightforward to get involved with computer audio. I firstly ripped 15 CDs onto my laptop using dbPoweramp. With AccurateRip built-in, the tracks were checked against a database to ensure they were bit perfect. All I then needed to do was to find a way to play these bit perfect copies of my CDs. I tried Foobar and Jriver. Foobar was the easiest and simplest software to use so that was my choice and it is free. Ah… a problem. How do I connect my laptop to my Audionote DAC 2.1x? I needed a USB to SPdif (Sony Philips Digital Interface Format) coax cable. No such thing. What was needed was a box of electronics to convert the USB output from my laptop to the coax SPdif input of the DAC. I tried a few and eventually settled on the Musical Fidelity. It was limited to 24/96 but did a great job. I was able to enjoy all the benefits of digital audio including the convenience of having all my 1600 CDs at my fingertips.

Since then I have tried various streamers and I currently use an Auralic Aries that connects to a NAS drive with all my music. The Aries has a coax output that feeds the coax input of my Audionote DAC 2.1x. As well as sounding excellent this set up has allowed me to play my CDs including those I had forgotten I had.

When Elite Audio sent me the Matrix Audio Quattro II to review they included a Matrix X-SPDIF 2 USB to SPdif convertor, the subject of this review.

If you read my review of the Quattro II (and if not, why not?) you will know that Matrix Audio makes audio differently to other companies. This convertor is housed in a solid aluminium case that is CNC machined. Not something normally seen at this price. And it uses good quality components not the usual 2p resistors. It has an asynchronous digital interface and a user configurable IIS port to avoid the losses caused by digital signal protocol conversion. The X SPDIF 2 has a built-in high-quality femtosecond clock with an FPGA processing unit. This chunky box can playback up to 32bit/768kHz PCM audio stream and a 1bit/22.4MHz DSD audio stream The X SPDIF 2 uses a new generation XMOS U208 that is an 8 core digital signal processing unit with a powerful multi-core and multi-threaded processor. And the X-SPDIF 2 uses 2 Accusilicon high-quality femtosecond clocks as references for 44.1kH and 48kHz frequencies and their multiple sample rates. All of this powered by low noise power supplies.


OK enough of these technicalities how did it sound? This box is so flexible I was not able to test all of its input and outputs. For example, I do not have an IIS compatible DAC. Anyway I initially used it connected to my laptop via USB with the SPDIF coax output going into a Metrum Octave DAC. I listened to it via my Stax headphones to get an overall feel for the sound.

And it was good; no it was damn good.

I knew what the outcome would be when I compared it to the Musical Fidelity, it was clearly outclassed and in reality there was no comparison. This was with CD Quality music at 16/44.1. With a 24/96 high quality recording the gap between the two opened up considerably. I know this is a little unfair as the MF is older but it was highly rated. Comparing some 24/192, 24/96 and 16/44.1 tracks showed the significant gains from CD quality to 24/96 although the improvement from 24/96 to 24/192 was less significant but then it always is.

OK on to my main system with a Metrum Octave DAC, a Pass Labs XP12 preamplifier feeding a Pass Labs XA 30.8 power amplifier and in to my Audionote E Silver Signatures. The sound really opened up and gave a great 3D feel to the music. The bass was exceptionally tight and well controlled and really only missed a small amount of the ultra-deep bass. The mid-range was clear without being sharp or sterile. And as with the Quattro II voices were very clear and it was easy to make out what was being sung even if the language was not English. The top end literally sparkled. This little box of tricks was doing a great job.

Although the bass was very tight it did not flow as well as I was used to. However, I thought the finger of suspicion should have been pointed at my Metrum, so in went the Audionote 2.1x. The bass flow was restored, with the added bonus of more bass weight. The X SPDIF 2 was really showing what my high quality DACs were capable of. I then tried it out on my Esoteric PO3 and DO3. My version of this Esoteric transport and DAC does not have an USB input. The XSPDIF -2 showed what it could do, even in this exalted company. Under this super microscope there is a small reduction in image size, very deep bass and some musical flow compared to my Auralic Aries. But do not forget the cost difference. One is £400 and the other £1500 and one is made of high quality aluminium and the other plastic.

That makes the XSPDIF-2 a bit of a steal and I recommend it.



PCM 16-24Bit /44.1kHz48kHz88.2kHz96kHz176.4kHz192kHz DSD64(DoP)


PCM 16-32Bit /44.1kHz48kHz88.2kHz96kHz176.4kHz192kHz352.8kHz384kHz705.6kHz768kHz

DSD64/128/256/(DoP) DSD64/128/256/512(Native)

NOTE: The IIS LVDS port is not a commonly used interface, currently, it has no uniformed interface standard.

"In line with PS AUDIO standard" refers to the signal definition of HDMI connector is defined exactly the same with PS AUDIO device, but it is not guaranteed that the X-SABRE Pro is compatible with all the devices conformed to this definition.