Well, I went ahead and ordered both the sound decoder and the speaker/fuel tank, but no instructions.  The locomotive as it is, is DCC only.  The number is 6910.  Where would I be able to get written instructions on attaching the speaker and the new board?  I don't want to foul this up.
BPR

Hi,

I have a DD40X with DCC on Board.   How do I add sound to it?