Good theremin project

Hi! I'm looking for a good theremin project to build. I found a lot of shematics so it's a bit hard to choose. I've done some electronics so I'm not a newbie. Does anyone know a good one to build?

Try the "RS Theremin" for a good starter project. Either that, or the Jaycar theremin kit is a fun one to build. Both are highly modifiable and with tweaks, can be quite playable.