....by Capt Cox which incorporated the gramaphone into a drop down conversion chart, pretty handy. I don't have the details handy but try this link;
http://www.subsim.com/radioroom/showthread.php?t=118945
The gramaphone has it's own folder within the game and, I think, is all .mp3 files. Check the properties of the files there and simply ensure that any .mp3 files you add to that particular folder match the required properties, you should be good to go.