I checked its official website and these formats are listed as output: AUDIO Formats:M4R, AC3, AAC, WMA, OGG, APE, MKA, AU, FLAC, CAF, SD2, AIFF.
AS you can see there is SD2 format, but only for the output mode. These are the files for the input mode: MP3, AAC, AC3, M4A, WMA, MKA, WAV, FLAC, OGG, APE, MP2, AMR, AIFF.
My advice is to install Easy Video Converter+ and load an SD file, then choose the MP3 format, for example.
I checked its official website and these formats are listed as output: AUDIO Formats:M4R, AC3, AAC, WMA, OGG, APE, MKA, AU, FLAC, CAF, SD2, AIFF.
AS you can see there is SD2 format, but only for the output mode. These are the files for the input mode: MP3, AAC, AC3, M4A, WMA, MKA, WAV, FLAC, OGG, APE, MP2, AMR, AIFF.
My advice is to install Easy Video Converter+ and load an SD file, then choose the MP3 format, for example.