I recently bought a 950B/770 "B-stock" combo. I noted that the B-stock 950 was a "blue dot" and assumed that it had all the latest updates and fixes. I was anticipating no problem with hiss, but did a check anyway. The first time I turned the unit on, there was a definite hiss present, albiet low. The level of hiss didn't change with volume level changes. I was in mild shock. But before I could do much, it was time to leave my home for a while, so I just shut the system off and left. I was thinking about what to do until I got home. I thought I would do a bit more investigating and try to determine if this was more or less hiss than my few-years-old THX certified Onkyo Ampli-Tuner. I used one channel of the Onkyo as a pre/pro on the 770 and got a sense of if, when and how much hiss occured under certain circumstances. Once I had a good idea of this, I restored that one channel to the 950 and powered up again. A mystery of the universe occured. The hiss level of the 950, both in the one channel I had switched to the Onkyo and back, as well as the other six channels, which had remained connected to the 950 during the Onkyo switch, had almost entirely disappeared. All of a sudden, the 950B/770 combo had become one of the most quiet systems I've experienced. What happened to the 950 between the first power-up and the second or third power-up, I don't know. But it's been quiet, when it's meant to be, ever since.