I have used Bryston, Mcintosh (452 & 600s) and none could touch the Sanders Magtech for my 3.7s and now 20.7s. A great pairing with Maggies is solid state power like the Magtech and tube source, here I started with a C2300 and upgraded that to a C1100, source DAC is a Modwright Elyse which provides a very sweet combination.
Brett
Brett