Hello all,
Can't find anything like information on adding an AC3 RF socket for the European Sony MDP-640D player.
I'm making a small request (almost a sos ) if a member of the forum knows about this modification.
There is the photo of the MP-31 card of the player as well as the service manual.
Maybe thanks for the help

Output of Q402 or R409 where it splits off to R415 on the AF-52 board is your AC3 RF tap point. Alternatively you could use the side of R415 not connected to the bandpass filter.