No, didn't go out today, I'll have a look tomorrow morning and maybe give it a go then.
Got the normal fin in at the moment.
What makes them hum?
Is it because they are loose?
I remember having a board with a Lexan star fin in many years ago and had that phenomenon of having the fin hum really loudly when I was dropping fast down a wave face.
I actually thought it was pretty cool

BTW, what ever happened to the star fin? Are they still around?