TNPA3911. This board has no suffix.
TNPA3814. This board has no suffix.
TNPA3812. There is no suffix for this board.
TNPA3818 This part has no suffix.
TNPA3855S is a substitute for TNPA3855E.
Part number found on board.
These board has the suffix stamped on the board. The suffix on this board is AC.
Both left and right speakers included.