Hey, yyzsantabarbara! For your benefit to assist you in your decision making process I am pasting in this comment on Krell mono blocks you’re considering. This comes from a moderator on a FB Krell member group.
“I have a pair of Solo 375 XD’s and despite them not having a crazy oversized power supply as typical in older Krell models, they are performers and can handle most anything you throw at them. Controlled and accurate bass, warm mids and highs. Non-fatiguing.
In fact, I MIGHT be on the verge of buying a pair of 575 XD’s to biamply my Egglestonworks Viginti. 575 XD’s on bass with 375 XD’s on the mids and highs.
All connected via CAST.
I would not go down the line to anything else, personally. XD is currently they best sounding amps Krell has made, to date.”
good luck to you in your decision process.