High powered amps for low sensitivity

I have a pair of speakers that are 3 way with raal ribbon tweeters

Several amps I have do not like the 84 db sensitivity or 4 own load at higher volumes and with dynamics

The speakers sound fabulous when not pushing the amps limits

I am running out of usuable volume in my system due to a .24 mv mc cartridge and the high demands

Looking for something very dynamic and natural sounding that can handle a hard load to drive these