Strange Behavior when measuring Phono to Output Loads (ground loop?)

[VAR]

Thanks Matt for the suggestion- will hook back up and zoom in a bit later this weekend. I snuck in some time to hook up the NAD to my speakers and a TT and just listened to some LP’s- Phono sounds fine at a level that the tests showed should have caused a problem (and beyond until my wife complained), so I am pretty confident in the amp not being a problem. Actually, the NAD sounds good through both the phono and CD inputs.

[VAR]

So here are some expanded Time plots:

and:

and 1 more:

Hopefully it will mean something. I am going to look at the Time display through the CD input for comparison as well…Thanks!