My 970 does not make any noises when switching sources. I bought my 970 brand new at the end of may this year along with a used outlaw 755 200x5 amplifier and so far I have had no problems. The sound for movies is great a big upgrade from my old 1050. Music also sounds good, very full and dynamic, with a lot of detail. I have heard the 990 with a similar set up and I do think the 990 sounds a bit better with music, but almost the same quality for movies.