We call Crave, Model D, CAT WASP, Pro-1 and all the others „semi-modular“ synthesisers. They are fully fledged stand-alone Synthesizers. But they also integrate themselves into the big modular world of Eurorack. A couple of patch cables and a single module and you’re in!
It's very easy to upgrade and enhance the sounds and capabilities: give your Crave a second oscillator, change the filter on the Model D or enhance the Neutron with a sequencer. We start small in this video by adding only a single module.