Looking to replace my (Mcintosh)

Love Platinum Audio Solo's. Those speakers love power. They have just an 84db efficiency. I live just a few miles down the road from where the company was located in Bedford NH. My local dealer sold the Platinum line. I would look at the Parasound A23+ and ideal the Bryston 4B3 or a used 4B SSt2 to save some money. Great speakers but they love power. Best bass response I ever heard out of a monitor. Designer Phil Jones loves getting as much bass as possible out of his speakers. The cost is you need a lot of power.

McIntosh MC 452. Plenty of power and great sound.

Jeff, I feel somewhat qualified to answer as I have owned a mac 7100, and I am a fellow Jeff. I actually miss the punchy lively sound of my old 7100, I ran it with a ARC LS1 and into some Thiel 2.2s, I have fond memories of that system. Anyway that was long ago, I am a huge fan of Wyred4 sound. One of their 250 watt amps will likely get the job done. What preamp are you running?
Thx Jeff

Pre-amp is Mcintosh C-28 but that could change as well