Comparison between high end preamp and av processor?

So have learned it’s difficult to integrate hifi and ht with hope of achieving the best SQ.  So thinking about getting a high end processor, eg NAD, Maestr, to get great hifi sound.  Problem I have had is that ht sq suffers when signal passes thru a line stage preamp when doing ht bypass.  So get better hifi but ht sq suffers. Sucks!!
Anybody compare preamp hifi sound with a hifi signal from a high end av processor 

thanks