If you are using a portable MiniDisk to record, the headphone output (3.5mm stereo mini-jack) is not a good idea for input to an analogue input on a sound card.

BUT! most of them have a Line Out socket (also 3.5mm stereo mini-jack) which is suitable.

You will probably find that most of the 'noise' you get is simply down to over-driving the input of the soundcard.

If you haven't a line output, turn the volume down on the MD player, and up on the line input of the soundcard. Play about with the balance between the two until you get the best results - a clean, undistorted sound, with a reasonable platback level.

Good software has a facility for filtering out the soundcard's inherent noise - you ask it to record some silence, and it fingerprints the noise for later filtering.

I would suggest that most people would not notice the difference, particularly if you are recording a session which is going to be a less-than-professional standard of recording, and using the recording primarily for learning tunes - which, I think, was the original query.

I produced my one-and-only album on cassette, and later transferred it to my hard drive, and wrote it to CD. The sound quality is as good as the original cassette - really, a lot of the debate about 'quality' is over-stated, as the differences are in frequencies out of human earshot! Now a dog...

The debate about loudspeaker cables is a typical case in point - oxygen free copper has an advantage for the manufacturer (easier to draw it out thinner), but the difference isn't audible, and hard enough to see on an oscilloscope. Polarised cables are total poppycock - loudspeaker signals are AC, not DC...

At long last people are beginning to realise they've been had!! Thick cable is better than thin cable (better current rating), and lots of fine strands are better than a few thick strands (surface effect), but that's as far as it goes!

For the 'record'(!!) I'm a full-time sound engineer...