Hello everyone, this is my first post in this forum...
I've recently discovered that the BCA-NWHD3 adapter that came with the Sony NW-HD3 player can also be used with Sony MZ-N10 NetMD player. Both devices have the same proprietary port for data transfer and charging. All you need to do is to cut a piece of plastic that supports the adapter when connecting to the device (I used my Dremel tool to cut it; very easy stuff). Then you can attach the adapter to MZ-N10 and use a regular mini USB cable to connect the MD player to your computer. You can also charge the player via DC-in jack with an auxiliary AC-DC adapter. I use a 5V Sony PSP power adapter by the way; it works flawlessly for charging MZ-N10.
Unfortunately, you cannot attach the BCA-NWHD3 adapter to the charging cradle. Because of the plastic housing, it doesn't fit into the cradle.
Hope this information may help someone who is searching for a "hard to find" USB cable for MZ-N10...
Here are some photos: