Actually they have been with any file, whether MP3 or other.
To move the files onto my MD player/recorder I first use CDex (a freeware CD ripper) to get the files on my hard drive. I started doing mp3's but to get the better quality I have now ripped them as WAV's. Then I import them in to OpenMG, after that I Check-In the files as LP4's or LP2's. With the WAV files I should be getting the best quality, but it doesn't seem to matter.
What is interesting is that the static I hear is always at the same level. In other words, if I turn up the volume I just hear the music louder, the static level doesn't increase. I have sensitive ears so I don't play the music loudly. I keep it at about 7-9 on the volume. At this level I can hear the static in the background.
When I turn the volume off (turn it to 0) I don't hear the music at all, but I do hear the static once again at that constant level. However if I pause or stop the music then the static is gone completely and I hear complete silence.
I guess I was wondering if this is just something that is common to MD players that when the playing mechanism is engaged you hear some static, kind of like the old tapes that you would hear a hiss at the same constant level whenever the playing mechanism is engaged.
You could test it by playing a MD and then turning the volume off and see if you can still hear a little static. I don't think that it comes from the bit rates because the static doesn't get loader as I turn up the volume only the music gets louder. Perhaps this is just a problem for people with sensitive ears.
Thanks for your help in tracking this down. I just want to know if I have a defective MZ-S1.