GUSTARD U12 32Bit / 384KHz DSD XMOS USB Digital Audio Interface silver

For me the U12 is definitely worth the money. Previously I ran my Windows computer's native optical S/PDIF signal into my DAC (Schiit Bifrost Uber). The U12 is incrementally - but noticeably - better. Redbook played from JRiver Media Center sounds bigger, blacker, and more rounded. It's simply closer to DSD, and much more pleasant to listen to. I'm genuinely impressed. The fact that it has pulled my 44.1 FLACs a bit further away from harsh treble hell makes it a keeper for me. The U12 sounded a bit bright/harsh upon first use but it cleared up within the first day. Expect some burn-in time. The device itself functions flawlessly, accurately displaying all sample rates from 44.1 to 384, DSD64, and DSD128. I do appreciate seeing the sample rate display, it's helpful to know what's actually being fed to the DAC as I fiddle with various software settings. The only difficulty is getting the XMOS USB driver to install. It comes included on CD but Norton Anti-Virus flagged it as a trojan horse. (I imagine it's actually safe.) In any case I used the Luckit modified driver, which you can find in this Head-Fi thread: http://www.head-fi.org/t/736294/gustard-u12-usb-interface-8-core-xmos-chip/30. Worked great. Bottom line - I'm very thankful this product exists at this price. It has made my Redbook collection more enjoyable.

I loved the sound when it worked, which was about 10 days. My Windows 10 laptop processed an update and rebooted. The U12 has refused to reconnect to the laptop. Disconnected USB and reconnected. Deleted and reinstalled driver. Shows up on the device manager, but is highlighted because the driver (v3.34) is unsigned. So, apparently the update to Windows 10 prevents devices from using unsigned drivers. The U12 is now a paperweight until they update the driver..which they don't plan on doing. Their advice is to turn off driver certification, which involves rebooting the laptop using Shift+Restart and navigating through some menus. And you'll have to do that every time you turn off (or restart) the computer. NO THANK YOU! Back it goes...

I am pairing it with Macbook Pro at one end and Bryston BDA-1 on another, using High grade USB cable and COAX cable respectively. Software I am using is jriver. Now, to start with.. in Mac it works out of the box. No driver is needed. however USB on Mac currently support output upto 192k (Midi) ( if all system sounds passing through Gustard u12). however when playing media using Jriver you can push much higher Bit rates and depth like DSA etc and it shows the reading of Bit rate played on etc on its mini easy to read display. Since its feeding to Bryston so I had to restrict Jriver to push only upto 192k so that bryston can understand and decode it and then pass it to my Preamp. Now, as you can see... with Mac I didn't have to struggle with drivers & so forth.. setup was done within 10 minutes. over 30 minutes worth of efforts went into tweeking the system to restrict it to only send 192k which in not due to Gustard but due to my DAC in picture ( which is Love for its tonal quality) . Having said that DAC shook Hand with Gustard like a lost brother and instantly tuned in to Better sounding music. No Jitter, Connection lost or any other problem so far. it just works every time I switch to Gustard from my Wadia. it was improved the tonal quality of media being played. made with quality materials inside out. This is Bang for every Buck.

I purchased the U12 for the I2S output. The "HDMI" I2S port is proprietary and not HDMI-compliant but rather borrows high speed, low jitter components from HDMI and uses them to deliver precision I2S audio to a DAC. So don't connect the I2S output to a regular HDMI port as it will not function. The U12 would have gotten 5 stars except a few I2S signals are out of phase with the ad hoc "PS Audio" I2S method. As a result when connected to a PS Audio type HDMI I2S DAC the L - R channels are reversed and absolute audio phase 180 deg out. To fix the issue you can replace the HDMI port driver (LVDS047) with a SN65LVDS391D which corrects the polarity of the differential I2S signals on the cable. One wire is also needed to connect the chip pin 8 to Vcc instead of ground. (Lift pin 8 and attach to pin 4 Vcc). A $4 fix for me but can be deal breaker for the unskilled. Where the U12 earns 4+ stars is the sound quality is very good given its low price. I have another USB to I2S box (Off Ramp 5) that costs 18x the price of the U12. Even with a few days of runtime the U12 is holding its own against the OR5. Great bargain if it holds up over time.

This absolutely will not work on Windows 10. I've been a Windows software developer since Windows 3 and without opening serious security risks, the drivers will not install.

Not many will need this device, but for those who do it is a great value. The U12 provides for digital signal path from my computer into the digital crossovers and class-D amplifiers in my M-Audio DSM3 studio monitors: Mac to U12 via asynchronous USB 2.0; U12 to DSM3 via IES EBU. This is an amazing, unique, niche product. Superb sound. Highly recommended.

As others have said, this seems to be a good upgrade for those using a laptop as a source. I noticed an improvement in sound stage clarity immediately.

Excellent usb to spidif converter. Sounds better than the built in usb in my dac, It's a steal at this price.