Is your Cassette recorder physically plugged into an OUTPUT PORT of your computer or laptop? What make/model is your computer? Is it a Desktop PC or a laptop?
If you're trying to record audio with an old cassette player/recorder (like from back in the 70s), and you just are putting an old style cable-microphone up to the computer or laptop speakers--this WON'T WORK! You need to have a cable running from the computer's audio out port (such as SPEAKER OUT port; mini-bnc) into the INPUT PORT of your cassette recorder. I worked with a Customer of mine who was a professional recording engineer and this is how he does it. Otherwise, due to discriminatory decibel mismatch and any background noises in your...