Suggestion for best stereo amp ?

Pierre:   

Sounds like you enjoy the sound from the Krell/Wilson combo. The problem is not with your setup it is with your other half.

I have long been a Krell/Wilson listener and truly believe that you might regret a move to lesser (more acceptable product). 

Holidays are coming so consider that you are in a good leverage position.  To swap out gear will be costly and ultimately you might not like the results. How about keeping the sound system as is and make an investment in some Diamond stud earrings for your wife.  Ask nothing in return but that she tolerate your stereo problem.

This way everyone wins!   

Happy Holidays!
Perfect_sound  

Consider the Naim 500 with the 500DR power supply.  It is incredibly natural sounding (especially when paired with the Naim 552 pre-amp).  The 500 is fast and powerful.  It is essentially two mono blocks housed in a single box.

Krell recently upgraded their line to “XD”. From what I’ve read its been well received. 

Instead of asking people on A'gon what to replace your Krells with shouldn't you be asking your wife which amps aren't going to pose the same response as the Krells ? 

+1 on the Naim 500 series power amp, analog preamp, digital front end (streamer/DAC) with Naim 500 DR power supply unit.

Or highly consider T&A gears they are excellent. The CH Precision, MBL, Tidal, Gamut, Audionet & Soulution are excellent too. The Gryphon that was recommended are also phenomenal. Gryphon makes excellent gears.