About loading from external audio sources
Spectaculator can load programs and data from audio sources connected to the Line-in socket of your soundcard.
Using this, you can load your old programs from their original cassettes into Spectaculator. Once loaded, save a zx-state (.szx) snapshot of the program for use next time.
If you're using your original tape lead that came with the Spectrum, you normally need a mono to stereo jack plug on the end as most Line-in sockets on soundcards require a stereo plug.
Although this feature was originally designed to allow loading from real cassettes, there's nothing stopping you from connecting up other sources such as a Minidisc player (if you have Spectrum programs recorded onto Minidisc).
Tip
You will probably need to experiment with the volume controls on your audio source to get programs to load correctly. As a start, set the volume at a level where the program loads into a real Spectrum.
Note
The signal coming in from the soundcard overrides the signal from the virtual cassette recorder. Make sure you disable this feature when you are not using it.