@audphile1 1 month on the U2, mostly running 24/7. Should be stable by now.
Currently an Audio Envy USB and power cord on the U2. I was using a DH Labs USB. And I have an older USB that came with an Orchid DAC I had a few years ago, but haven't tried it yet.
PS Audio DSD Mk2. I reloaded the original firmware but have reverted back to the current firmware. Synergistic Blue power cord.