I have a MZ-NHF800. I have just take it out from the bag. it is completly new, and i find that i can listen how the engine of the minidisks works... through the hearphones.
I was so sad when i discovered such NOISE. It was like static, but more like data and disk working. After some hours of sadeness, I unplugged the "remote control" from the minidisc, and i connected DIRECTLY the hearphones (SONY MDR-7506). And that was the solution.
That remote control has problems with the static and with the minidisc engine, it captures everything
But now i know how this thing works.
Do you have any other idea for having a solution to this?