I test sound output from smartphone to record them through line-in on my computer. I have two different scenarios:
- the phone has jack output: I have a jack male cable to connect the phone to my computer and it works fine
- the phone has no jack: in that case I use a USB to jack adapter with the same jack cable as in the previous scenario but I don't get any sound. If I plug a headset instead of the jack cable, I can hear the sound without any problem.
I'm a bit puzzled because the USB to jack adapter works fine when using a headset but when using another the jack to line-in cable, there is no sound (line-in volume on my computer is at 100%). I have tried this on 3 different phones from 3 different brands (but all Android base) but it doesn't work.
Am I missing something?