I have a similar issue, my guitar's foamed at the nut (can't foam the bridge - Fender vintage saddles), it happens with 2 different pickups at the neck position, insane way higher ping when palm muting. Yours sounds like noise from either the headstock or behind the bridge. Foam takes care of that.
If not, I had to completely EQ the frequency out which was around 1.7 K, you could locate yours.
Also on the Badonk, but to a lesser degree on other hx amp models.
Took it to the store, into a Mesa Triple , no ping at all :-/