The Platinum Reference I is the biggest chanllenge to power amps. I have yet to find anything that make it sound acceptable to my ears.
I have matched it with about a dozen amps 5 years ago (from $$$$ SS amps to tube amps )and gave up at the end. No matter what you feed through it, it never sound as open and relax as some other better monitor speakers. I ended up ATC SCM10s as it sound much more realistic, relax and open ( very dynamic without the constrain I felt from the Platinums.)
I have matched it with about a dozen amps 5 years ago (from $$$$ SS amps to tube amps )and gave up at the end. No matter what you feed through it, it never sound as open and relax as some other better monitor speakers. I ended up ATC SCM10s as it sound much more realistic, relax and open ( very dynamic without the constrain I felt from the Platinums.)