The “errors” are NOT the problem and they aren’t really errors. It just means the optional FFmpeg library (used for importing/exporting various audio formats) is not installed.
How is your turntable connected?
Make sure you’ve selected the correct Recording Device. (Don’t select anything that says “loopback”).
We may need to know more about your hardware so tell us as much as you can…
Turntables need a phono preamp (which may be built-into your stereo receiver or the turntable itself). And for an analog connection you need a line input (blue on a regular soundcard). If you have a laptop you may need a USB audio interface.
Thank you for your reply.
I have an Audio Technica ATL0120XUSB connected to my windows computer through USB cable.
I actually realized that if I select Phono mode on the turntable, no sounds is coming out from speakers. So I selected the Line mode (thinking carefully, it’s obvious ^^), now the export works.
But the sound that is coming out from speakers is very strange, like loudly saturated.
Make sure you’ve directly selected the USB device as your recording device. “Stereo Mix” or anything that says “loopback” can create an internal feedback loop.
It’s not obvious to me that would affect the USB output but I think I’ve read that before. It should be in the user manual.