excalibur:
I finally found an area I can represent, "idiot", that is. I have found the main differences in the 4 Theremins I have, is the player. When played by someone else, they sound fine, but when played be me they all sound ---- not so fine. So there you have it, mine must be the "lemons" that sometimes slip by the quality control department. :-)
On the serious side, you will find a vast knowledge base of experienced people here that will be able to answer your questions. Having only been playing (?) for a year now, I can't be of a lot of help, but others can. As far as my opinion when comparing them the pre amp, amp, speakers, ect, need to be taken in to account also. If you are new at Theremins, keep in mind that you will have to spend a Lot of time practicing and not get discouraged. I play for a hobby and don't intend on playing professionally, so my goals are not as lofty as others. The Theremin can be a source of peace and tranquility AND a source of frustration and despair, all at the same time.
God Bless and may your adventure in the "Ether" be a blessing.----