warm up time resolution audio opus 21

I have not noticed that with my RA Opus 21, and I have owned it, happily, for many years.
Of course mine is always left plugged in, (so it is in standby mode).
You might want to give Jeff Kalt, at Resolution Audio, a call to discuss it with him. (A nicer guy you will never meet.)
Good Luck in solving your problem.

That is an issue I have experienced with many of my cd players (Meridian 588, MF kW and my current Esoteric XO3SE). I leave my player on all the time and it only takes one CD or so to warm up, so issue solved by leaving it on. Gear does need time to warm up. When I know I am going to listen to my gear, I let it play for an hour or so before I go in my sound room and all is wonderful.

When in use I leave mine on all the time. No reason not too. Great player too, especially for the used prices they are going for.