I know over the years a lot of people have posted about issues with the a/v sync on the UB820 when fed to an AVR, and I was one of them. From the day I bought it, it always required a ~90ms delay set in the sound settings to get the video and audio to line up, but even then it wasn't ever perfect. I went to troubleshoot and when I turned Dolby Vision off and turned it back on again in the UB820 player settings, and was offered two choices: mode 1 or mode 2. Mode 1 lets the TV process the DV, while mode 2 has the player process the DV. I had this set to mode 2 (not sure why, I probably just blindly followed a set up video when I first hooked it up) so I switched it to mode 1 and reset the audio delay to 0ms and threw on a 4k disc. Everything is literally perfect now. With the delay, you could still never get it exact but switching to mode 1 removed the need to even try and sync them up manually. It works the way it is supposed to work now. I'm really happy. This had been driving me crazy for the better part of two years and it was a simple switch in a partially hidden setting. You can't get to mode 1 without turning DV on and off again. If you are having a/v sync issues on your UB820 and AVR, give this a shot. And just for those who want this info, my AVR is the TX-RZ50 and my TV is the Sony Bravia 8 II.   submitted by   /u/itsrealbattle   to   r/4kbluray [link]   [comments]