Here is a software application, called Free Sound Recorder, that may be very useful in the event you need (for example) to save a cassette tape to a CD or a LP to a CD (or to your computer).
Here is how it works: Any sound that you can pass through your sound card, Free Sound Recorder can capture it and convert it (to MP3, WMA or WAV format). In my testing I took a voice recorder (with sound already recorded on it); connected a 3.5 mm male-to-male cable to the earphone jack on the voice recorder and to the line-in jack on the computer and used Free Sound Recorder to capture the audio. The end result was quite impressive. You may need a different type of cable in the event you are capturing audio from a different type of device (e.g. cassette player, LP player, etc…).
Free Sound Recorder is a perfect audio recorder to record your own voice, music or any other sound by working directly with your sound card. It supports the record input/source from a microphone, streaming audio from the Internet, external input devices (e.g. CDs, LP, music cassettes, phone line etc.) as well as other applications like Winamp, Media Player, etc. With built-in advanced audio record engine, the recorder produces high quality recordings.
Main Features of Free Sound Recorder
Allows you to record audio into MP3, WMA or WAV format directly.
Allows you to pre-define audio recording qualities to help quickly set and manage recording parameters.
Built-in advanced audio record engine to produce high quality recording.
Allows you to preset/preview your audio recording device before starting record.
Build-in WMA WAV MP3 decoder.