Dave,
It’s the hiss on the clean channel even when the volume is completely rolled off. Second video you can hear the mids knob affect it while the volume is at zero compared to the lead channel at zero which is silent, as expected.
On the gain channel with master up it makes the expected amount of signal noise as gain is increased. It starts quiet and increases when the knob is turned. Totally normal.
Clean channel is just really noisy across the board at baseline level. I’ve never encountered an amp that makes noise when the gain/volume is at zero/off. It’s REALLY loud in the room. Tubes are VHT/Ruby. I tried JJ, tung sol, ehx…everything in the house. That windy sound in the first video is pretty much gone, FWIW.