FWIW, my 975 had similar crackling noise problems. I sent it back to Outlaw and it was diagnosed as a faulty hdmi board. I was charged a fair price for its repair and shipping back. The returned unit, didn't work as well as the one I shipped back. The crackling noise was still there and the HDMI ARC no longer worked. I documented the noise with sound recording clips using various inputs and from my headphones. Outlaw was great and asked me to ship it back on their dime. They said the problem was the main board and said they replaced it at no charge and shipped it back. This repair cured the crackling noise but I was suddenly having hdmi audio problems. I tried a HDMI reset and eventually a unit reset, eventually the entire unit bricked (no audio output from any input including the tuner and analog).

Outlaw had me send it back on their dime again. This time they basically said it couldn't be repaired. They were great and refunded the amount I spent on repairs and shipping (except for the original shipment back to them). I ended up getting a 976.