[yuga1]

For someone who is after the most complicated way to do a conversion this could be useful

I am sure there is plenty of proprietary windows software which handle wma but for linux I am aware of only soundconverter and avconv without gui...

I was only teasing and my knowledge of Linux is close to zero. How about ffmpeg? Since you know your way around a command line, that tool should be able to handle virtually everything. Alternatively, you might be able to run something like foobar2000 in wineHQ?
Have you seen this? https://github.com/dfaust/soundkonverter

Yes foobar would be better for sure. Thanks for suggestions I didn't know. For now I'm done