Bursts of noise in DTS HD MA tracks

[kstebor]

I've been noticing this lately and it's driving me crazy. Several films I own which have DTS HD MA audio tracks exhibit intermittent bursts of full-spectrum noise. I've noticed it primarily in older films, since their audio content generally doesn't contain a lot of high frequencies but the noise emitted does. I tried watching King Kong (1933) yesterday and couldn't even get through it, the noises were so distracting.

I was certain the noises were digital in origin and not present in the original soundtrack due to their frequency content, so I decided to try to analyze them. What I found was pretty strange. There appear to be consistent full-spectrum bursts 120 times per second, with a select few of them being significant enough to hear. The attached screenshot shows two spectrogram recordings from the headphone output of my receiver of a very brief slice of audio from King Kong (1933) at about 49:30. The top half shows when my player set to bitstream and the bottom half shows the player set to PCM, which makes the regular nature of the bursts much more clear. The very wide burst in the middle is the one that's audible in that slice.

Does anyone have any idea what might be going on here? Is it some kind of sync issue? Is it perhaps related to the infamous "DTS bomb" of the past? Some more details I've noticed are: reducing the treble on the receiver does not reduce the bursts, eliminating all additional processing with "pure direct" mode does nothing about the bursts, and the bursts are present on both the DST HD MA track as well as it's DTS core. They are not present in the HBO MAX version of the film, which has a Dolby soundtrack.

My setup is a Sony UBP X800, Pioneer Elite VSX LX102, and TCL S405. Any help would be greatly appreciated.

EDIT: I think we can ignore the 120 Hz pulses. I've been testing some more and that might just be a product of 60 Hz ground loop hum from hooking my receiver up to my audio interface. However, I've confirmed the presence of the clicks on another setup.