Does anyone experience sound improvement from restarting power off and on of DAC?

I haven’t tried it, but based on what you are doing, it may be something is getting too hot. Make sure it’s ventilated.

There have bee a number of small compute intense boxes over the years I’ve owned which malfunctioned due to the manufacturer not taking care to ventilate and add appropriate heat sinks. These were usually wifi routers but also indludes Roon like streamers. Additional cooling often helped.

My Mytek DAC also suffers this if fed very high sample rate music, so I put pucks underneath it and limit the signal rate.

With the wifi routers I sometimes would drill a hole over an offending chip and add a heat sink and micro fan. Not saying you need to, just saying it’s happened so often that I’m kind of surprised it doesn’t happen now.

I'd feel the dac and look for any particularly hot areas above or below and take care that any hot areas get extra ventilation.

With my Holo May Kitsune DAC attention must be paid to ventilation. Over-heating can be an issue otherwise. The original placement of the DAC and its separate power supply was technically inverted which was a mistake not made plain in the instructions. Placing the power supply atop the DAC - even with 3 inch tall spacers - could sometimes result in a chirping noise coming from the speakers. This was due, as I finally surmised, to overheating the DAC after an hour or two of playing. Placing the DAC atop the power supply stopped this annoyance.

My component rack is by the nature of my space vertically oriented with little lateral space around the component, so stacking a two part component such as the DAC and its power supply was an obvious convenience. Lately I have decided to just affix the DAC’s power supply to the side of the component cabinet thereby taking the over-heating issue completely out of the loop.

No idea what a one minute shutdown would cure, and especially with the DAC getting hot.

@mitchb - I would contact PS Audio and ask them.  PS Audio DACs are different from pure chip based DAC as they use FPGA (field-programmable gate array) with custom software to process the signal.  There could be a problem there.  Also, have you upgraded to the newest software version?

...From PS Audio's sales brochere:

DirectStream converts every input signal, both PCM and DSD, to single-bit, high sample rate 20X DSD signal. Use of a FPGA rather than an off the shelf DAC chip provides immense processing power, resulting in complete lack of digital glare, and allows the owner to download OS updates as they are released.

Years ago I read something about this and clearing a buffer, memory cache (or something) was the reason given for the improvement in SQ.

DeKay