1)   OJOsoft M4A Converter 2.7.4
It can convert M4A files to MP3, MP2, WMA, OGG, MP4(audio only), AAC, AC3, WAV. This converter not only converts M4A files to audio formats , but also supports converting video and audio files to M4A, AAC, MP4(audio only).

 2)   RER M4A Converter 3.7.4
RER M4A Converter is a professional audio converter to convert M4A files to MP3, MP2, WMA, MP4(audio only), AAC, AC3, WAV and convert audio files to M4A.