I recently completed my build of the CAPS v2.0 server and was itching to try it out. Previously I had been using a regular PC to stream my FLAC files via my router to an SB Touch modded with the Toolbox mods. The SB Touch was being used with a Buffalo II DAC. I was very pleased with the sound quality but knew, like a good audiophile, that there had to be more.

After the server rebuild I had tweaked Win 7 and J River Media Center 16 in accordance with the articles here on this site. I had also installed the SoTM inline power filter and Tx USB PCI board. The only thing I didn't have was a USB interface to my DAC. I knew I wanted to try I2S at the DAC end and began looking around for a suitable converter. I was intrigued by the Exa product because it was designed for DIY users and the fact that it would slot right into my Buffalo DAC without any problem. I wasn't put off by the fact that it uses proprietary ASIO drivers or the fact it has multichannel capability even though my intention is to stick to two channel at this time. It can support sampling rates up to 384 Khz.

I decided to try it out and placed an order. While I waited I installed the Squeezeserver software onto the CAPS server and used it to stream music via ethernet to the SB Touch. The improvements were pretty much what I expected. All I really did was replace one PC with another, albeit noiseless one with some tweaks to the software. There seemed to be a lowering of the noise floor which allowed more detail to come through.

When the Exa board arrived I installed it in the Buffalo DAC and installed the driver on the CAPS server with no issues. The Exa board has to take power from the same power supply that supplies the DAC, although my power supply had some issues supporting both devices, so with some excellent tech support from George at Exa I hooked up some batteries to test the board that way until I can replace the faulty parts in my power supply. I then set the Buffalo for I2S input by turning off the S/PDIF dip switch.

I connected the USB cable from the SoTM USB card to the Exa board and using J River MC 16 I selected some music at 24/96 that I had recently downloaded from HD Tracks and sat back to listen. I was very impressed. This was on a completely different level, with an increase in the amount of air around instruments and voices and it just became much more realistic and lifelike. Once again the noise floor was lowered allowing much more detail to shine through. There appeared to be so little distortion that I was able to turn up the volume a lot higher, while doing so brought to light another observation. There was a lot more power in the performances, especially drums. The sound is very clean and clear. Average recordings, or most likely, masterings, remain what they are but the difference between them and good ones are like night and day.

All in all I think a very good product from Exa and I'm very satisfied.......for now.

Colin

This review can also be found on http://www.computeraudiophile.com/content/ExaU2I-32bit384kHz-USB-I2S-Asynchronous-Interface-Review.