NuPrime is a Class D amp.
Some ClassD’s do sometimes have a nasty (edgy) turn on sound, not a soft bump that some linear amps have.
And they can also depending on the output filters roll off point, emit HF continual noise from the tweeters.
I’ve seen results over time of these two noises continually combined cook (blue’d coil) a Wilson 8 tweeter by so called highly regarded Class D monoblocks, that had the output filter that rolled of too high, the owner would turn his system on and off quite a bit as he was a reviewer, it had a nasty sounding squelch at turn on from the tweeter and had continual hiss from the tweeter you could just hear from 1.5mts away.
Cheers George