Audacity 1.2.6 on Windows 7 and the Compressor is set to default threshold -12 ratio 2:1 attack .2s and normalize to 0.
My saved Wav file is amplified to maximum without clipping. I open fiIe use the edit tool to select all of the track and then use the effects tool to get compressor, I preview and it is perfect, I then use compressor by pressing ok, and the final outcome is that it is not loud like the preview button when it is pressed.