There is a certain amount of hiss from any amp. Now whether you can hear it or not, thats where Paul's comments come in.

(I completely disconnected my pre/pro, and just had amp to speakers, and I have it. But like I said, have to put my ear right up to the tweeter, *and* angle it just right to hear it. My level of low level "hiss" is a function of the amp. In my case, when I went from a 150 W/channel Nak PA-5AII to an Acurus A200x3, effectively 300W per channel for stereo listening, the "hiss" did increase, but it never approached "HISS".)

But what dealcatcher is talking about is a lot more than hiss: but HISS.

If the amount of hiss changes from hiss (low level) to HISS (high level) due to the "state" of the 950 (i.e., volume level, input selection, etc.), then that can have nothing to do with the amp and must be due to the 950...