“there is no real replacement for the human ear.”
I can see that when it comes to tuning the remaining notes in the tempered scale, but you can’t set that first note unless you have perfect pitch or whatever it’s called, and I’ll bet a lot of very good musicians don’t have perfect pitch.
So, bottom line, most people need to start tuning with a tuning fork or something that will do, say, A 220.
I understand. :)