Not a stupid question at all! No noise at 0. And again, the 'noise' isn't the normal noise floor that almost all of those systems produce. I swear I think this is coming from the display or some other source of EFI.
Curious you should mention the display. There is an option to turn it off temporarily, but I still hear the noise, even when off. But I'm going to go play with the display brightness.
Now I need to ask a question. What's the VFD?
(and thanks for taking the time to read/respond!)