Designing A Theremin as a Beginner

Hi,

For quite some time now, I've been interested in the concept of the theremin, and in order to understand this fascinating instrument better, I thought of building one myself. On this website, I came across a schematics post called a vine-box theremin, which seemed to be not too hard to make and still have good sound quality (I thought that mostly because the picture intrigued me and the author sounded confident). Turned out that, according to many comments, the circuits were faulty, and the instrument wouldn’t work. 

At this point, I wasn't sure how to proceed and I felt kinda lost.

Some posts in the Construction Forum suggest beginning with the pitch oscillator. Which sounds like a great plan to begin, but I'm not quite sure which circuits to trust.

My question is if there are some builds on this website that work and are also good enough for actually building a well-playable instrument later on.

I would be very happy if you could help me.

Thanks in advance.

"My question is if there are some builds on this website that work and are also good enough for actually building a well-playable instrument later on."  - GraphiX

Good question.  I will say:

1. You need an oscilloscope to do this kind of work, preferably a decent digital scope.
2. There is rarely enough attention paid to the quality of the coils, and coils are the heart of the Theremin (if you're looking for good performance).
3. Proper grounding is super important.
4. There isn't anything mysterious going on, but it will probably take a while to figure that out with all the lame schematics and hype out there.

For oscillators, Buggins designed a really nice one: http://www.thereminworld.com/forums/T/33275?post=221506#221506

Obtaining RF chokes is a real problem now since Bourns and Hammond stopped making them.  The very best coils are single layer solenoids, but winding one to make 20mH or so is something of an ordeal, and it will be rather physically large (think RCA pitch coil).