You can grab, edit and save samples from your soundcard in Traktor. It’s way simpler than I thought. I’ve uploaded a mapping which should make it even simpler.
Cheers to all the posters BTW I don’t know if it’s coincidence but I just had to reinstall my soundcard drivers because it stopped working, and that’s never happened before. It played okay, but wasn’t showing any signal on the recording side of the stereo mix. Anyway, the reinstall fixed it.