I have otg adapter can I transfer song android phone to USB Sony mp3 walkman

Solution
You need a programme that converts from the .wav format to MP3 I won't recommend one because there are so many out there on the Net but they will all come with different amounts of advertising. I f you find one that cists a smll amount, it will be ad-free.

Search for wav to MP3 and you'll find the choices. It's best to store the converted file in a separate folder. I suggest naming it MP3 music.
You need a programme that converts from the .wav format to MP3 I won't recommend one because there are so many out there on the Net but they will all come with different amounts of advertising. I f you find one that cists a smll amount, it will be ad-free.

Search for wav to MP3 and you'll find the choices. It's best to store the converted file in a separate folder. I suggest naming it MP3 music.
 
Solution
I think that the Sony player would have to have OTG for you to be able transfer files directly from the phone to the it.
Transfer the files to a computer and from there to the DAP.