Yes the noise is normal it's the heater cycling on and off and is a hopperlabs inside joke that it's the hopper chirpinglol
So this hum is also very quiet and I have now tested 3/5 of my hoppers, all of them have the noise.
Strange that nobody else has it. I still have to try my 2 others, but since it is not only on one of my devices and the hopper employee also told me it
was normal, everything is good for me !!! because all devices have it
and you can only hear it when the device is on and you hold the oven close to your ear
It can hardly be such a coincidence that only my 5 devices have it and no one else
or you mean with click the same what i mean with hum..it sounds it sounds like a fast running quieter.
but it doesn't matter. everything is fine for me