I now have nearly 250 hours on the Gustard U26. It seems to have stabilized. My impressions are that, in my system, it provides the Musetec MH DA006 with an improved digital input signal via I2S, and thus a better result in what comes out of the 006. I have heard better resolution, sound stage depth, clearer images, and more dynamic punch. It was like thinking you had perfect 20/20 vision and then being given glasses that allow you to have 20/15 vision. The improvement was clearly noticeable. I can’t comment on how the U26 compares to other DDC’s because I have not heard any of the better ones. Since the U26 is available through Amazon, 30 day returns allow a trial.
I listened to both streaming and local flac and dsd files via a Lumin U2 Streamer to the U26, then into the 006. Preamp is a Hegel P30, power amp, a McIntosh mc312, and speakers are Kef Reference Ones, augmented by two SVS SB-4000 subwoofers.
I have no complaints, except when playing dsd through the streamer the U26 reversed right and left channels. (i.e. with the successful U26 settings for dsd, PCM and dsd were both reversed.) My solution was to simply swap the 006's right and left output cables. Probably with more experimentation I could find the correct settings to make the swap unnecessary.