A friend of mine drove his 3.7s with a Audio Research Ref 110 tube amp. Sounded wonderful. He decided to sell it and downsize and now the Ref 110 is driving my 2.7 with no issues at all. Best amp I have owned. The Ref 150 is supposed to have a better power supply which would have better woofer control. Whatever amp you choose look at the power supply specs. It isn’t always about the WPC.