Hi Jochen, I have been modeling HPF1 in Genesys software. I am attaching a .PDF (not sure why it captured some file text at the top).
The bottom curve- dashes- is the response of the stock filter, while the dot curve is replacing the 1uF caps with 3uF- quite a difference. I'll next pace the cap from in to out and look.
I'll also model HPF2.
This seems to indicate why the brassy sound though. I even question why this filter is needed for SSB?