Is it possible to have two separate collections within Amarok and switch between them?

I have approx 30k music files 25% flac 75% mp3, but I only ever listen to one type of file at a time so i don't want my mp3s all mixed in with the flac as i have alot of dupes, but I prefer to use the collection tab to navigate rather than playlists.

Any suggestions? At the moment i have my mp3s loaded in Rythembox and Flac in Amarok, but Amarok is sooooo much better than Rythembox

Thnx