How do I get audacity to listen on my line-in port, instead of my microphone port?

20.04 Ubuntu
Audacity 3.0.2
Installed distribution’s release

This is probably a very common issue, but I cannot find any answer for it. I’m attempting to rip vinyl onto my computer using audacity. When I connect the amp to my microphone port, audacity can record it (terrible quality though, and coming through only one ear), but when I connect it to my line-in port, audacity doesn’t pick it up. I cannot explicitly select what device to record from meaning it is stuck on default, however it is the only thing plugged into my system (sound wise), and even so it picks it up when plugged into the microphone port.

If anyone knows any fix to get audacity recording from the right port it would be a great help.

Hi, Mr.
Not an expert here, but I suppose Audacity (and so any software) can’t record the amp connected in line-in because of signal level (level of sound of the input channel).

The mic input accepts microphone signal level, which is low, and line-in expects a stronger signal, like an instrument (or microfone after a pre-amp). Maybe your amp does not have line-in signal running in its cables, and maybe recording by the mic input is not good because of the hardware; e.g., in my 10-year notebook, any p2 microphone (mic input) gets low final quality. USB mics, althogh, are ok, because they have the audio hardware in themselves.

TL;DR
So, I would suggest you test connecting the vinyl output to the pc, to record in Audacity, throught a (USB) audio interface, if possible.

Windows guy here. Try Transport > Rescan audio devices. Then select line-in from your Device Toolbar.