Best amp for $550 to mate with the following...

Ok, easy one and move on it. Get the Muse 100 up for sale here for $375. Won't do better under $500.

Do yourself a huge favor and get the Class d audio. It's almost a joke that it costs $500 ish when it beats $5000 amps that I've heard.

Only responding because I saw two amps mentioned that I am familiar with, the Sonographe A250 (sold mine a month ago, very good amp)and ClassD Audio ( I have the 125W. model).
I recently heard the Crown XLS 1500, and compared to the ClassD Audio amp, the Crown won hands down.
The Sonographe is a fine choice, but they hardly ever come up for sale.

CLASS D AUDIO !! My 300/600 Watt SDS470C sounds amazing and I`m coming down off a Rogue ST90 that I loved but it just didn`t have the power I need/wanted.

For the $$$ it reminds me of the NAD 3020 I bought new waaay back !

Interesting I've heard the xls 2500 and I prefered the class d
audio. However my friend who owns the crown also has a pair of
hypex ncore mono blocks. He has often said he prefers the
crown.