Definitely has the "chug chug" of a GE.
DFF
Ah, that is why it sometimes (especially at the start of the video) it sounded almost like steam loco chuffing. In tunnels, when fuller sound reflected back to the microphone, it sounded more like what I would expect a Diesel loco to sound like. But since I know Jim's layout is in a Diesel era, I knew it couldn't be a steam loco.