Error code.

[Axel]

Interesting! I've had the exact same error once and also heard it happening. The amp literally stopped outputting music for a split second only my sub continued.

Took a picture of the error on the screen, exactly the same as you report, but haven't bothered yet to report it. It happened on the second or third day and I had it running continuously (playing music or a burn-in disc at low volume when away) since first power on. Removed power cord and reinserted it and it hasn't happened since, just checked no errors logged. Don't really think this reinserting the power cable solved it other than fully resetting the device. I blamed it on it being new and/or a calibration error.

My D is connected to a P3 PowerPlant to output an exact and steady 230V so I doubt it's really an external over voltage issue.

Thanks, Antoine. 
I won't bother looking at my supply circuits, but I'll reset my amp. as you did and see what happens.