My friend gave me a bunch of M4A files.  Can I play them on my m250 player or do I need to convert them first.  Does anyone know of a good converter?

well, I am so sorry for my late answer, but But why not a person to answer your question? Personally think that the problem is not difficult, Sansa Media Converter application is a very good converter, https://kb.sandisk.com/app/answers/detail/a_id/4431/~/downloading-and-launching-the-sansa-media-converter The Sansa Media Converter application is available via the Sansa Firmware Updater, an application designed to deliver the latest software support, User’s Manuals, and product firmware right to your desktop. in addition, I suggest you convert m4a to WAV.http://www.videoconverterfactory.com/tips/m4a-to-wav.html Compared with M4A to MP3, M4A audio to WAV can keep the original audio quality. good luck