i listened to the sim and others a few years ago and purchased the mcintosh ma-6500 integrated amp to go with my nht 2.9's. The nht's need a lot of power and they need a smoother sounding amp to tame the forwardness of the nht line. The mcintosh did not have enough power for the 2.9's (and the ma-6900 was not out yet). I even tried bi-amping the 2.9's with nht's sa-3 subwoofer amp, better, but something was missing. I then purchased a classe preamp and cd player with a pair of odyssey monoblock amps and things got much better. Classe equipment have a nice warm (tube-like) sound to them. Same with the Mcintosh. For integrated amps, i would listen to the Classe 151 and the Mcintosh ma-6500 or the ma-6900. I had all nht for quite a while (audio and home theater use, 2.9's, 1.5's, super zeros, super ones, super center 2, 2-sub two's) and have sold all of them (except the 2 sub two's) and purchased smoother sounding speakers. I think you would open up your options on front end equipment if you would change out your speakers. If you keep your nht's, IMO, you will need to stick to a warmer sounding amp and an amp with a lot of power, a hard combination for an integrated.