Tuning your instrument

Thanks Hilton, I appreciate the quick reply. You put my mind at ease for now.

Hello Paul...welcome! Playing a theremin IS a little like playing a fretless instrument, EXCEPT it's even more difficult because you don't even have a fingerboard or anything else to steady yourself against. Part of the battle is training yourself to hold a position and be very still. I can't seem to do that myself standing up (and my flat feet hurt too much), so I play seated, which has improved my playing tremendously. I use a tall padded stool called a "posing" stool.
As Hilton alluded to, "tuning" a theremin is a misnomer. What your actually doing is setting the "range". Most theremins have a range of a few to several octaves (highest note at the antenna to the null point (0 Hz). With the "tuning" knob you can set it so the entire range falls within several inches of the pitch antenna all the way to a few feet away. What you decide is "right" depends on your height/arm length, and how/what you intend to play. I recommend that when you decide how you like the range set, pick a point of reference (your body at arms length, etc) that you can use to set the range consistantly every time. Personally, I use the volume side of the cabinet away from the pitch antenna on my Etherwave Pro.
There are at least two reasons a theremin needs to be "tuned". One is that all electronics are to some degree affected by the temperature. One of the reasons some theremins cost more than some others is they use components that are more stable and less affected by temperature. The other reason is the theremin works using body capacitance. Body capacitance depends on the surface area (size) of your body, and everyone is different.
I have/had a Kees theremin (it's been "lost" on it's way back to Ohio after an upgrade), so some words of advice. One... allow your Kees theremin to "warm up" at least ten to fifteen minutes before playing. If you don't, you'll notice the pitch will continue to rise ever so slowly on you until it fully warms up. Two....avoid large swings in temperature. Three...VERY important...DO NOT use the battery adapter. Once the battery starts to get a little weak, bad things start to happen. The pitch rises as you approach the volume antenna and the sound goes from a singing angel to a howling alley cat! When you get your theremin run right out to Radio Shack and buy a 9 volt adapter. You need one that's at least 200 milliamps. Important...take the theremin with you! The adapters don't come with a tip (sold separately) and there are about two dozen different ones. Don't try to eyeball it..I found out the hard way.
Good Luck! Let us know how you're getting along once you've had your theremin for a while.

Wow, Jeff! What can I say? Thanks so much for the info. Now I'm curious about the warming up aspect. You stated that the Kees should be allowed to warm up for 15 minutes. Is that unique for a Kees or do all Theremins need time to warm up? Does the Moog or others take less time and does the warming up time indicate anything about the quality of the unit?

And on a separate note, I have a drum set, guitars, bass and a 4 track recorder in my house. So, as soon as I feel brave enough, I'll put something onto disc and try to make it available to hear. I have plans to try to record a cover the track Black Sabbath by er...Black Sabbath and use the Theremin to replace the vocals and and some of the guitar. It sounds great in my head. Can't wait to see how it sounds on disc.

Paul - No need to say anything. What did you expect? A nebulous answer that doesn't really answer the question?
While the Kees theremin is a good theremin for it's price, it uses a modified Jaycar PC board...not necessarily the highest quality component available. It is more sensitive to temperature changes than the Moog Etherwave for example. To be ensure pitch stability, it's best to let the Kees theremin warm up thoroughly for "at least" 15 minutes. More is even better.

I forgot to mention...passing a current through any electronic component, especially resistors, will cause them to heat up until they reach a point of stability. When you warm a resistor up, the resistance increases slighty.
This happens to any electronic device to some degree. The theremin just happens to be especially sensitive to the phenomena since it detects minute changes in capacitance. It's just the nature of the beast.

There's also another reason why playing the theremin can be so incredibly difficult, particularly for touring musicians. Being in a different environment means changes in humidity, temperature and moisture that can affect the condutivity of the air. That quite naturally means that the even if you leave the volume antenna dial in the same place, tuning is going to change from day to day and from place to place.

That makes the theremin even more difficult to play that a fretless instrument- because the frets keep changing their positions ever so slightly!

Very interesting stuff guys. Thanks again for all of the info. (Kees just e-mailed me and I don't think I'll have my unit for another 2 weeks and I'm going nuts waiting for it.) I love a challenge and all of these invisible variables presented by such a unique instrument is really getting me excited to play. I've played drums for many years and I'm hoping that my endurance and my drumming style will help me. I use my index finger, thumb and wrist to propel my sticks as opposed to my arms so, maybe it'll help with the meticulous fingering.

If I do tackle this instrument, I guess I'll look into a Moog. I wasn't ready to drop almost $400 on something I've never played before. Also, there is a very big and very old electronics supplier locally and they specialize in RCA components. I know they have alot of old stock and specialty items. I'm gonna swing by with the RCA diagram and see what they say. I know it's a long shot, but it's worth a try.

Got my Kees Theremin yesterday. I played it for a little while last night. It was an absolute blast! One small problem I've encountered with the power supply. I went to Radio Shack and they didn't have a jack that fit. The biggest jack they have is 5.5 mm and the jack for the Theremin is 6.5mm. Question; can I take the jack that came with the Kees for the 9 volt adaptor and solder it to the Radio Shack power supply? Kees states that it needs a positive tip. The power supply has a minus sign right before the spot where you plug in the jack. Does that matter?

Nevermind. I found a big electronics place and got the problem squared away for half the price of Radio Shack.

So, I was messing around with my Theremin this weekend. After experimenting and just trying to get somewhat of a feel for it, I grabbed a tuner and attempted to hit a note-any note- so I could have a reference point, but I couldn't hit one. It was a cheap guitar/bass/other type tuner. Has anyone tried this before? Maybe these types of tuners are not capable of recognizing a Theremin tone? Also, no matter how still I stayed, It sounded like it was fluxuating ever so slightly. The only thing I can compare it to is how an automobile engine sounds when it's in need of a tune up. Although Kees provided some instructions for tuning, I'm still not sure if I have it set correctly. Is there any video that demonstrates the tuning?