How much hard-drive space do they take up on your PC? Not that knowing that will help too much as the block size on the PC filesystem may well be different from that on the Empeg.

Bear in mind that the 4Gb Empeg unit has 3910Mb of space for tunes, or at least that's how much Empeg's Emplode (Windows tune uploader) says there is.

Cheers,

Mark.