On the HSX, it works like this: You plug the Rio600 directly into the HSX and use its front panel to put the songs onto the Rio600.

Emplode does not talk to the Rio600, it doesn't know how to speak that protocol. The HSX has an implementation of it on board, in other words, the HSX can talk to the 600, but it's not in emplode.

The type of USB port on the empeg is not the kind where you can plug the Rio 600/800 into it (it's only a slave port), so even if they did port that software from the HSX to the empeg, it wouldn't work.