Is there any way of telling up front if a particular flash going to whine or not?

Isn’t it the capacitor charging up with the magic? Source quieter magic?

You have described my tinnitus precisely. 😥

my 540ez makes dogs howl in the next post code.

I assumed they all did it…at least the proper powerful ones. Handy audio cue that its charged.

I have an ancient 80s looking bargain bin one that whines really loudly; my modern (must be 4-5 years old) Olympus one is silent.

I find the Nikon ones make a short wine when first turned on or after firing on full power. I think most will make some noise when charging.

Is it not caused by the foil in the caps vibrating as charge is applied, like the reverse of a condenser mic?

As gwaelod says, handy audio cue you’re gonna get a nice bright light in a mo’…

My 580EXII and 430EXII don’t. Or my hearing is foobar and I can’t hear them.